Chromene compound

A photochromic compound featuring a large fading rate to prevent a change in the color tone at the time of fading, exhibiting little color after aged, and exhibiting good durability in the photochromic property. The photochromic compound is a novel chromene compound having a substituted phenyl group at the second position of the naphthopyrane ring and an alkyl group at the fifth position thereof, and is represented by, for example, the following formula, ##STR1## wherein R1 is an alkyl group, R2 and R3 are substituted phenyl groups, and R4 and R5 are substituents.

 

What is claimed is:

1. A chromene compound represented by the following general formula (1), ##STR191##

wherein

R1 is an alkyl group in which a carbon atom bonded to a naphthopyrane ring is a primary carbon atom, a secondary carbon atom or a tertiary carbon atom,

R2 and R3 are substituted or unsubstituted aryl groups or substituted or unsubstituted heteroaryl groups which may be different from each other, or R2 and R3 may be coupled to each other to form a substituted or unsubstituted adamantane ring, a substituted or unsubstituted bicyclononane ring, or a substituted or unsubstituted norbornane ring,

R4 is a substituent,

n is an integer of 0 to 4 representing the number of the substituents R4 and, when n is 2 or larger, R4 may be the same or different substituents,

R5 is a hydrogen atom or a substituent, and wherein when R1 is an alkyl group in which a carbon atom bonded to the naphthopyrane ring is a primary carbon atom, R2 and R3 may be each a group represented by the following formula (2), ##STR192##

wherein X is an oxygen atom or a sulfur atom, or a group represented by the following formula (3), ##STR193##

wherein R6 is an alkoxyl group or a trifuloromethoxy group, and k is 0 or 1,

and R2 and R3 may be different from each other, and at least either R2 or R3 is a group represented by the above formula (3), and

R5 is a hydrogen atom.

2. A chromene compound represented by the following general formula (1'), ##STR194##

wherein

R1 is an alkyl group having 1 to 10 carbon atoms in which a carbon atom bonded to the naphthopyrane ring is a primary carbon atom,

R2 and R3 are groups represented by the following formula (2), ##STR195##

wherein X is an oxygen atom or a sulfur atom, or groups represented by the following formula (3), ##STR196##

wherein R6 is an alkoxyl group or a trifluoromethoxy group, and k is 0 or 1, and R2

and R3 may be different from each other and at least either R2 or R3 is a group represented by the above formula (3),

R4 is a substituent, and

n is an integer of 0 to 4 representing the number of the substituents R4 and when n is not smaller than 2, R4 may be the same or different substituents.

3. A chromene compound according to claim 2, wherein R1 in the general formula (1') is an alkyl group having 1 to 4 carbon atoms in which a carbon atom bonded to the naphthopyrane ring is a primary carbon atom.

4. A chromene compound according to claim 2, wherein R1 in the general formula (1') is a methyl group or an ethyl group.

5. A chromene compound according to claim 2, wherein in the general formula (1'), R2 and R3 are both groups represented by the formula (3), R6 in the formula (3) is a methoxy group, an ethoxy group or a trifluoromethoxy group and when k=1, a fluorine atom is substituted for an ortho position relative to the group R6.

6. A chromene compound according to claim 2, wherein in the general formula (1'), R1 is a straight-chain alkyl group having 1 to 4 carbon atoms in which a carbon atom bonded to the naphthopyrane ring is a primary carbon atom, R2 and R3 are groups represented by the formula (2) or groups represented by the following formula (3'), ##STR197##

wherein R6 is a methoxy group, an ethoxy group or a trifluoromethoxy group, k is 0 or 1,

and R2 and R3 may be different from each other, and at least either one of R2 or R3 is a group represented by the above formula (3'), R4 is a group or an atom selected from is an alkyl group, an aryl group, an alkoxyl group, an aralkyl group and a halogen atom, n is an integer of 0 to 2 representing the number of the substituents R4 and when n is 2, R4 may be the same or different groups or atoms.

7. A chromene compound represented by the following general formula (1"), ##STR198##

wherein

R1 is an alkyl group having 3 to 15 carbon atoms and in which a carbon atom bonded to the naphthopyrane ring is a secondary carbon atom or a tertiary carbon atom,

R2 and R3 are substituted or unsubstituted aryl groups or substituted or unsubstituted heteroaryl groups which may be different from each other, or R2 and R3 may be coupled to each other to form a substituted or unsubstituted adamantane ring, a substituted or unsubstituted bicyclononane ring or a substituted or unsubstituted norbornane ring,

R4 is a substituent,

n is an integer of 0 to 4 representing the number of the substituents R4 and when n is not smaller than 2, R4 may be the same or different substituents, and

R5 is a hydrogen atom or a substituent.

8. A chromene compound according to claim 7, wherein in the general formula (1"), R1 is an alkyl group having 3 to 6 carbon atoms in which a carbon atom bonded to the naphthopyrane ring is a secondary carbon atom or a tertiary carbon atom.

9. A chromene compound according to claims 7, wherein in the general formula (1"), R1 is an isopropyl group or a t-butyl group.

10. A chromene compound according to claim 7, wherein in the general formula (1"), R2 and R3 are aryl groups having 6 to 14 carbon atoms or heterocyclic groups having 4 to 12 carbon atoms, and each of the aryl groups having 6 to 14 carbon atoms or the heterocyclic groups having 4 to 12 carbon atoms may be substituted by at least one group or atom selected from the group consisting of:

an alkyl group having 1 to 4 carbon atoms;

an alkoxyl group having 1 to 4 carbon atoms;

an aralkyl group having 7 to 10 carbon atoms;

an alkylcarbonyl group having 2 to 7 carbon atoms;

an amino group having, as a substituent, an alkyl group with 1 to 10 carbon atoms or a hetero atom-containing alkyl group;

a substituted or unsubstituted heterocyclic group having a nitrogen atom as a hetero atom, and in which the nitrogen atom is bonded to the aryl group having 6 to 14 carbon atoms or to the heterocyclic group having 4 to 12 carbon atoms;

a condensed heterocyclic group formed by the condensation of the heterocyclic group with an aromatic hydrocarbon ring or an aromatic heterocyclic ring;

an aryl group having 6 to 14 carbon atoms; and

a halogen atom.

11. A chromene compound according to claim 7, wherein R5 in the general formula (1") is a hydrogen atom.

12. A chromene compound according to claim 7, wherein in the general formula (1"), R1 is an alkyl group having 3 to 6 carbon atoms in which a carbon atom bonded to the naphthopyrane ring is a secondary carbon atom or a tertiary carbon atom, R2 and R3 are substituted or unsubstituted phenyl group which may be different from each other or are each a substituted or unsubstituted heteroaryl group selected from the group consisting of a furyl group, a pyryl group, a thienyl group and a benzothienyl group, R4 is a group selected from the group consisting of an alkyl group, an aryl group, an alkoxyl group, an acyloxyl group and a hydroxyl group, n is 0 or 1, and R5 is a hydrogen atom.

13. A chromene compound according to claim 1, wherein the chromene compound is a 5-isopropyl-2,2-diphenyl-2H-benzo(h) chromene.

14. A chromene compound according to claim 1, wherein the chromene compound is a 5-t-butyl-2,2-diphenyl-2H-benzo(h) chromene.

15. A chromene compound according to claim 1, wherein the chromene compound is a 5-isopropyl-2,2-bis(3-fluoro-4-methoxyphenyl)-2H-benzo(h) chromene.

16. A chromene compound according to claim 1, wherein the chromene compound is a 5-methyl-2,2-bis(4-methoxyphenyl)-2H-benzo(h) chromene.

17. A chromene compound according to claim 1, wherein the chromene compound is a 5-isopropyl-2-(4-methoxyphenyl)-2-(4-trifluoromethoxyphenyl)-2H-benzo(h) chromene.

18. A chromene compound according to claim 1, wherein the chromene compound is a 5-isopropyl-2-phenyl-2-(4-trifluoromethoxyphenyl)-2H-benzo(h) chromene.

19. A photochromic material comprising a chromene compound of claim 1.

20. A photochromic polymerizable composition comprising 100 parts by weight of a polymerizable monomer and 0.001 to 10 parts by weight of a chromene compound of claim 1.

21. A photochromic polymerizable composition according to claim 20, wherein the polymerizable monomer comprises 100 parts by weight of a radically polymerizable monomer, and 1 to 30 parts by weight of a compound having at least one epoxy group in one molecule thereof and a radically polymerizable group.

22. A chromene composition comprising 100 parts by weight of a chromene compound represented by the following general formula (1), ##STR199##

wherein

R1 is an alkyl group in which a carbon atom bonded to a naphthopyrane ring is a primary carbon atom, a secondary carbon atom or a tertiary carbon atom,

R2, and R3 are substituted or unsubstituted aryl groups or substituted or unsubstituted heteroaryl groups which may be different from each other, or R2 and R3 may be coupled to each other to form a substituted or unsubstituted adamantane ring, a substituted or unsubstituted bicyclononane ring, or a substituted or unsubstituted norbornane ring,

R4 is a substituent,

n is an integer of 0 to 4 representing the number of the substituents R4 and, when n is 2 or larger, R4 may be the same or different substituents,

R5 is a hydrogen atom or a substituent, and wherein when R1 is an alkyl group in which a carbon atom bonded to the naphthopyrane ring is a primary carbon atom, R2 and R3 may be each a group represented by the following formula (2), ##STR200##

wherein X is an oxygen atom or a sulfur atom, or a group represented by the following formula (3), ##STR201##

wherein R6 is an alkoxyl group or a trifuloromethoxy group, and k is 0 or 1, and R2 and R3 may be different from each other, and at least either R2 or R3 is a group represented by the above formula (3), and R5 is a hydrogen atom,

and 10 to 1000 parts by weight of a chromene compound represented by the following general formula (7), ##STR202##

wherein

R7 is an amino group represented by the following general formula (8), ##STR203##

wherein R11 and R12 are hydrogen atoms, substituted or unsubstituted alkyl groups having 1 to 10 carbon atoms, substituted or unsubstituted aromatic hydrocarbon groups having 6 to 10 carbon atoms, or heterocyclic groups, which may be different from each other,

or substituted or unsubstituted heterocyclic groups having a nitrogen atom as a hetero atom and in which the nitrogen atom is bonded to the naphthopyrane ring, or are condensed heterocyclic groups formed by the condensation of the heterocyclic groups with an aromatic hydrocarbon ring or an aromatic heterocyclic ring,

R8 and R9 are substituted or unsubstituted aromatic hydrocarbon groups, substituted or unsubstituted aromatic heterocyclic groups, or alkyl groups, which may be different from each other,

R10 is a substituent,

m is an integer of 0 to 4 representing the number of the substituents R10 and when m is not smaller than 2, R10 may be the same or different groups.

23. A photochromic polymerizable composition comprising 100 parts by weight of a polymerizable monomer, and 0.001 to 10 parts by weight of a chromene composition of claim 22.

24. A photochromic polymerizable composition according to claim 23, wherein the polymerizable monomer contains 100 parts by weight of a radically polymerizable monomer, and 1 to 30 parts by weight of a compound containing at least one epoxy group and radically polymerizable groups in one molecule thereof.

25. A photochromic composition comprising 100 parts by weight of a chromene compound represented by the following general formula (1), ##STR204##

wherein

R1 is an alkyl group in which a carbon atom bonded to a naphthopyrane ring is a primary carbon atom, a secondary carbon atom or a tertiary carbon atom,

R2 and R3 are substituted or unsubstituted aryl groups or substituted or unsubstituted heteroaryl groups which may be different from each other, or R2 and R3 may be coupled to each other to form a substituted or unsubstituted adamantane ring, a substituted or unsubstituted bicyclononane ring, or a substituted or unsubstituted norbornane ring,

R4 is a substituent,

n is an integer of 0 to 4 representing the number of the substituents R4 and, when n is 2 or larger, R4 may be the same or different substituents,

R5 is a hydrogen atom or a substituent, and wherein when R1 is an alkyl group in which a carbon atom bonded to the naphthopyrane ring is a primary carbon atom, R2 and R3 may be each a group represented by the following formula (2), ##STR205##

wherein X is an oxygen atom or a sulfur atom, or a group represented by the following formula (3), ##STR206##

wherein R6 is an alkoxyl group or a trifuloromethoxy group, and k is 0 or 1,

and R2 and R3 may be different from each other, and at least either R2 or R3 is a group represented by the above formula (3), and

R5 is a hydrogen atom, 10 to 1000 parts by weight of a chromene compound represented by the following general formula (7), ##STR207##

wherein

R7 is an amino group represented by the following general formula (8), ##STR208##

wherein R11 and R12 are hydrogen atoms, substituted or unsubstituted alkyl groups having 1 to 10 carbon atoms, substituted or unsubstituted aromatic hydrocarbon groups having 6 to 10 carbon atoms, or heterocyclic groups, which may be different from each other,

or substituted or unsubstituted heterocyclic groups having a nitrogen atom as a hetero atom and in which the nitrogen atom is bonded to the naphthopyrane ring, or are condensed heterocyclic groups formed by the condensation of the heterocyclic groups with an aromatic hydrocarbon ring or an aromatic heterocyclic ring,

R8 and R9 are substituted or unsubstituted aromatic hydrocarbon groups, substituted or unsubstituted aromatic heterocyclic groups, or alkyl groups, which may be different from each other,

R10 is a substituent,

m is an integer of 0 to 4 representing the number of the substituents R10 and when m is not smaller than 2, R10 may be the same or different groups, 10 to 1000 parts by weight of a spirooxazine compound; and 10 to 1000 parts by weight of a fulgimide compound.

26. A photochromic polymerizable composition comprising 100 parts by weight of a polymerizable monomer, and 0.02 to 1 part by weight of a photochromic composition of claim 25.

27. A photochromic polymerizable composition according to claim 26, wherein the polymerizable monomer comprises 100 parts by weight of a radically polymerizable monomer, and 1 to 30 parts by weight of a compound containing at least one epoxy group and radically polymerizable groups in one molecule thereof.

28. A photochromic lens made of a polymer of a photochromic polymerizable composition of claim 26.

29. A chromene compound represented by the following general formula (1'), ##STR209##

wherein

R1 is an alkyl group having 1 to 10 carbon atoms in which a carbon atom bonded to the naphthopyrane ring is a primary carbon atom,

R2 and R3 are groups represented by the following formula (2), ##STR210##

wherein X is an oxygen atom or a sulfur atom, or groups represented by the following formula (3), ##STR211##

wherein either R2 or R3 is a group represented by the formula (2) and the other one of R2 and R3 is a group represented by the formula (3), R6 in the formula (3) is a methoxy group, an ethoxy group or a trifluoromethoxy group and k=0 or 1, and when k=1, a fluorine atom is substituted for an ortho position relative to the group R6,

R4 is a substituent, and

n is an integer of 0 to 4 representing the number of the substituents R4 and when n is not smaller than 2, R4 may be the same or different substituents.

30. A chromene compound represented by the following general formula (1), ##STR212##

Wherein

R1 is an alkyl group having up to 10 carbon atoms in which a carbon atom bonded to a naphthopyrane ring is a primary carbon atom, a secondary carbon atom or a tertiary carbon atom,

R2 and R3 are substituted or unsubstituted aryl groups or substituted or unsubstituted heteroaryl groups which may be different from each other,

R4 is a substituent,

n is an integer of 0 to 4 representing the number of the substituents R4 and, when n is 2 or larger, R4 may be the same or different substituents,

R5 is a hydrogen atom, and wherein when R1 is an alkyl group in which a carbon atom bonded to the naphthopyrane ring is a primary carbon atom, R2 and R3 may each be a group represented by the following formula (2), ##STR213##

wherein X isan oxygen atom or a sulfur atom, or a group represented by the following formula (3), ##STR214##

wherein R6 is an alkoxyl group or a trifluoromethoxy group, and k is 0 or 1, and R2 and R3 may be different from each other, and at least either R2 or R3 is a group represented by the above formula (2).

31. A chromene compound represented by the following general formula (1') ##STR215##

wherein

R1 is an alkyl group having 3 to 6 carbon atoms and in which a carbon atom bonded to the naphthopyrane ring is a secondary carbon atom or a tertiary carbon atom,

R2 and R3 are groups represented by the following formula (2), ##STR216##

wherein X is an oxygen atom or a sulfur atom, or groups represented by the following formula (3), ##STR217##

wherein R6 is an alkoxyl group or a trifluoromethoxy group, and k is 0 or 1, and R2 and R3 may be different from each other and at least either R2 or R3 is a group represented by the above formula (3),

R4 is a substituent, and

n is an integer of 0 to 4 representing the number of the substituents R4 and when n is not smaller than 2, R4 may be the same or different substituents.

32. A chromene compound according to claim 31, wherein in the general formula (1'), either R2 or R3 is a group represented by the formula (2) and the other one of R2 and R3 is a group represented by the formula (3), R6 in the formula (3) is a methoxy group, an ethoxy group or a trifluoromethoxy group and when k=1, a fluorine atom is substituted for an ortho position relative to the group R6.

TECHNICAL FIELD

The present invention relates to a novel chromene compound which changes into a colored state upon irradiation with light containing ultraviolet rays such as of sunlight or light of a mercury lamp, the change being reversible, and exhibits excellent fading rate as well as excellent durability in the photochromic property, getting little colored even after it is aged. The invention further relates to a photochromic material, to a chromene composition, to a photochromic composition, to a photochromic polymerizable composition and to a photochromic lens, which contain the chromene compound.

BACKGROUND ART

Photochromism is a phenomenon which is drawing attention in these several years, and stands for a reversible action of a compound; i.e., a compound quickly changes its color when it is irradiated with light containing ultraviolet rays such as of sunlight or light of a mercury lamp, and resumes its initial color when it is no longer irradiated with light and is placed in a dark place. The compound having such a property is called photochromic compound. Though a variety of compounds have heretofore been synthesized, no common feature is particularly recognized among their structures.

U.S. Pat. No. 4,980,089 discloses a chromene compound represented by the following formula (A), ##STR2##

This chromene compound exhibits photochromic properties near room temperature (20 to 30.degree. C.) but exhibits a slow fading rate when it is placed in a dark place after it has developed a color upon being irradiated with ultraviolet rays. When the colors are mixed upon being combined with photochromic compounds having other color tones, such as a fulgimide and a spirooxazine having relatively fast fading rates, the hue changes when the colors fade.

Furthermore, PCT Unexamined Patent Publication WO95/16215 discloses a chromene compound represented by the following formula (B), ##STR3##

wherein B1 is an aminocarbonyl group or an alkoxycarbonyl group, B2 and B3 are hydrogen atoms, alkyl groups, substituted or unsubstituted phenyl groups or alkoxyl groups, m is from 0 to 3, B4 and B5 are substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted adamantylidene groups, or substituted or unsubstituted norbornylidene groups.

This compound exhibits an increased fading rate compared to the compound disclosed in the above U.S. Pat. No. 4,980,089 but is not still capable of completely preventing a change in the hue when the mixed colors fade. When aged, furthermore, this compound is more colored than when the compound (A) is aged.

PCT Unexamined Patent Publication WO95/16215 further discloses, as a comparative example, a compound represented by the following formula (C), ##STR4##

exhibiting, however, a fading rate nearly the same as that of the above-mentioned compound (A).

As described above, the conventional chromene compounds are not still satisfactory with respect to the fading rate and the color after they are aged.

DISCLOSURE OF THE INVENTION

The object of the present invention therefore is to provide a chromene compound which exhibits improved photochromic property, increased fading rate, and is little colored after it is aged and exhibits excellent durability in the photochromic property compared with those of the conventional chromene compounds.

The present invention was proposed in order to accomplish the above-mentioned object, and is concerned with a chromene compound in which the fifth position of a naphthopyrane ring is substituted by an alkyl group. The chromene compound of the present invention exhibits a large fading rate, permits the hue to change little when the mixed colors are to be faded, is little colored after it is aged, and exhibits excellent durability in the photochromic property.

That is, the present invention is concerned with a chromene compound represented by the following general formula (1), ##STR5##

wherein

R1 is an alkyl group in which a carbon atom bonded to a naphthopyrane ring is a primary carbon atom, a secondary carbon atom or a tertiary carbon atom,

R2 and R3 are substituted or unsubstituted aryl groups or substituted or unsubstituted heteroaryl groups which may be different from each other, or R2 and R3 may be coupled to each other to form a substituted or unsubstituted adamantane ring, a substituted or unsubstituted bicyclononane ring, or a substituted or unsubstituted norbornane ring,

R4 is a substituent,

n is an integer of 0 to 4 representing the number of the substitutents R4 and, when n is 2 or larger, R4 may be the same or different substituents,

R5 is a hydrogen atom or a substituent, and wherein when R1 is an alkyl group in which a carbon atom bonded to the naphthopyrane ring is a primary carbon atom, R2 and R3 may be each a group represented by the following formula (2), ##STR6##

wherein X is an oxygen atom or a sulfur atom, or a group represented by the following formula (3), ##STR7##

wherein R6 is an alkoxyl group or a trifuloromethoxy group, and k is 0 or 1, and R2 and R3 may be different from each other, and at least either R2 or R3 is a group represented by the above formula (3), and R5 is a hydrogen atom.

Other inventions are concerned with a chromene composition containing a chromene compound represented by the above-mentioned general formula (1) and other chromene compounds; a photochromic composition containing a chromene compound represented by the above-mentioned general formula (1), other chromene compounds, a spirooxazine compound and a fulgimide compound; a photochromic polymerizable composition containing a polymerizable monomer and the compositions; and a photochromic lens obtained by curing the photochromic polymerizable composition.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a diagram of a proton nuclear magnetic resonance spectrum of a chromene compound of Example 1.

BEST MODE FOR CARRYING OUT THE INVENTION

In the present invention, it is important that an alkyl group is substituted for carbon at the fifth position of a naphthopyrane ring. With the alkyl group being substituted for a carbon atom at the fifth position of the naphthopyrane ring, the compound of the invention exhibits a fading rate larger than that of the conventional chromene compounds.

In the general formula (1), R1 is an alkyl group. The alkyl group R1 may be the one in which a carbon atom bonded to the naphthopyrane ring is a primary carbon atom or the one in which a carbon atom bonded to the naphthopyrane ring is a secondary carbon atom or a tertiary carbon atom.

There is no particular limitation on the alkyl group in which a carbon atom bonded to the naphthopyrane ring is a primary carbon atom provided it is the alkyl group in which a carbon atom directly bonded to the naphthopyrane ring is a primary carbon atom. Other carbon atoms such as a carbon atom bonded to the primary carbon atom or the succeeding carbon atoms may be primary carbon atoms, secondary carbon atoms or tertiary carbon atoms. Among such alkyl groups, the alkyl group having 1 to 4 carbon atoms is preferred from the standpoint of yield of synthesis. Preferred examples of the alkyl group in which a carbon atom bonded to the naphthopyrane ring is a primary carbon atom include methyl group, ethyl group, n-propyl group and n-butyl group. Among them, the methyl group and the ethyl group are particularly preferred from the standpoint of easy synthesis.

There is no particular limitation on the alkyl group in which a carbon atom bonded to the naphthopyrane ring is ada secondary carbon atom or a tertiary carbon atom provided it is the alkyl group in which a carbon atom directly bonded to the naphthopyrane ring is a seconary carbon atom or a tertiary carbon atom. Other carbon atoms such as a carbon atom bonded to the secondary carbon atom or the tertiary carbon atom or the succeeding carbon atoms may be primary carbon atoms, secondary carbon atoms or tertiary carbon atoms. Among such alkyl groups, the alkyl group having 3 to 15 carbon atoms and, particularly, 3 to 6 carbon atoms is preferred. Preferred examples of the alkyl group in which a carbon atom bonded to the naphthopyrane ring is a secondary carbon atom or a tertiary carbon atom include isopropyl group, sec-butyl group, t-butyl group, iso-butyl group and t-amyl group. Among them, the isopropyl group and the t-butyl group are particularly preferred from the standpoint of easy synthesis.

In the above-mentioned general formula (1), R2 and R3 are substituted or unsubstituted aryl groups or substituted or unsubstituted heteroaryl groups which may be different from each other. Or, R2 and R3 may be coupled to each other to form a substituted or unsubstituted adamantane ring, a substituted or unsubstituted bicyclononane ring, or a substituted or unsubstituted norbornane ring.

Though there is no particular limitation on the substituted or unsubstituted aryl group, it is desired that the aryl group has 6 to 14 carbon atoms. Concrete examples of the aryl group include phenyl group, naphthyl group and tolyl group.

Though there is no particular limitation on the substituent of the substituted or unsubstituted aryl group, preferred examples of the substituent include alkyl group, alkoxyl group, trifluoromethoxy group, aralkyl group, alkylcarbonyl group, alkoxycarbonyl group, cyano group, substituted amino group, substituted or unsubstituted heterocyclic group having nitrogen atom as a hetero atom and is substituted or is not substituted by the nitrogen atom, or a condensed heterocyclic group formed by the condensation of the above heterocyclic group with an aromatic hydrocarbon ring or an aromatic heterocyclic ring, aryl group, acyloxyl group, nitro group, hydroxyl group and halogen atom. The above-mentioned substituents will now be described.

There is no particular limitation on the above-mentioned alkyl group. Generally, however, it is desired to use an alkyl group having 1 to 10 carbon atoms and, particularly, 1 to 4 carbon atoms from the standpoint of easy synthesis. Concrete examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, and t-butyl group.

There is no particular limitation on the alkoxyl group. Generally, however, it is desired to use an alkoxyl group having 1 to 10 carbon atoms and, particularly, 1 to 4 carbon atoms from the standpoint of easy synthesis. Concrete examples of the alkoxyl group include methoxy group, ethoxyl group, n-propoxyl group, isopropoxyl group, n-butoxy group, sec-butoxy group and t-butoxy group.

Though there is no particular limitation on the aralkyl group, it is generally desired to use an aralkyl group having 7 to 16 carbon atoms and, particularly, 7 to 10 carbon atoms from the standpoint of easy synthesis. Concrete examples of the aralkyl group include benzyl group, phenylethyl group, phenylpropyl group and phenylbutyl group.

Though there is no particular limitation on the alkylcarbonyl group, it is generally desired to use an alkylcarbonyl group having 2 to 15 carbon atoms and, particularly, 2 to 7 carbon atoms from the standpoint of easy synthesis. Concrete examples of the alkylcarbonyl group include methylcarbonyl group, ethylcarbonyl group, propylcarbonyl group, isopropylcarbonyl group, n-butylcarbonyl group, t-butylcarbonyl group and benzoyl group.

Though there is no particular limitation on the substituted amino group, it is generally desired to use an amino group having a substituent such as an alkyl group having 1 to 10 carbon atoms or an alkyl group containing a hetero atom. Among them, it is desired to use a substituted amino group having 1 to 5 carbon atoms from the standpoint of easy synthesis. Concrete examples of the substituted amino group include methylamino group, ethylamino group, propylamino group, isopropylamino group, dimethylamino group, diethylamino group, methylethylamino group, 2-hydroxyethylamino group and di-(2-hydroxyethyl)amino group.

There is no particular limitation on the substituted or unsubstituted heterocyclic ring having the nitrogen atom as a hatero atom and in which the nitrogen atom is bonded to the substituted or unsubstituted aryl group or on the condensed heterocyclic ring formed by the condensation of the above heterocyclic ring with an aromatic hydrocarbon ring or an aromatic heterocyclic ring. It is, however, desired that the heterocyclic ring is constituted by 2 to 10 carbon atoms and, more preferably, by 2 to 6 carbon atoms. The ring may include a hetero atom in addition to the nitrogen atom that is bonded to the substituted or unsubstituted aryl group. Not being limited to the nitrogen atom only, furthermore, there may be bonded an oxygen atom, a sulfur atom or a nitrogen atom. As the aromatic hydrocarbon ring or the aromatic heterocyclic ring bonded to the heterocyclic ring, furthermore, there can be exemplified an aromatic hydrocarbon ring or an aromatic heterocyclic ring having 6 to 10 carbon atoms. There can be preferably used a benzene ring, a thiophene ring or a furan ring. As the substituent for the heterocyclic ring or the condensed heterocyclic ring, there can be used an alkyl group having 1 to 4 carbon atoms. Concrete examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, and t-butyl group.

Piperidino group, morpholino group, N-methylpiperadinyl group, thiomorpholino group, aziridinyl group and pyrolydinyl group are concrete examples of the substituted or unsubstituted heterocyclic ring having the nitrogen atom as a hetero atom and in which the nitrogen atom is bonded to the substituted or unsubstituted aryl group or of the condensed heterocyclic ring formed by the condensation of the above heterocyclic ring with the aromatic hydrocarbon ring or the aromatic heterocyclic ring.

Though there is no particular limitation on the aryl group, it is generally desired to use an aryl group having 6 to 20 carbon atoms and, particularly, 6 to 14 carbon atoms from the standpoint of easy synthesis. Concrete examples Of the aryl group include phenyl group, naphthyl group and tolyl group.

Though there is no particular limitation on the acyloxyl group, it is generally desired to use an acyloxyl group having 1 to 15 carbon atoms and, particularly, 2 to 7 carbon atoms from the standpoint of easy synthesis. Concrete examples of the acyloxyl group include acetoxyl group, propionyloxy group, benzoyloxy group and (meth)acryloyloxy group.

Though there is no particular limitation on the halogen atom, concrete examples of the halogen atom that can be favorably used in the present invention include fluorine atom, chlorine atom and bromine atom.

Though there is no particular limitation on the position of the substituent of the substituted or unsubstituted aryl group or on the number of the subsituents, it is desired that the aryl group is substituted at the meta-position and/or the para-position, and the total number of the substituents is generally not larger than 3 and, preferably, not larger than 2.

There is no particular limitation on the substituted or unsubstituted heteroaryl group provided it is a substituted or unsubstituted heteroaryl group including a hetero atom such as oxygen atom, nitrogen atom or sulfur atom. It is, however, desired to use a substituted or unsubstituted heteroaryl group having 4 to 12 carbon atoms. Preferred examples of the unsubstituted heteroaryl group include furyl group, benzofuryl group, pyryl group, thienyl group, benzothienyl group, oxazolyl group, imidazolyl group, and pyrazolyl group. From the standpoint of easy synthesis, however, it is desired to use the furyl group and the thienyl group. Preferred substituents of the substituted heteroaryl group will be the same as the preferred substitutes of the substituted aryl group. There is no particular limitation on the position of the substituent of the substituted heteroaryl group and on the number of the substituents. Preferably, however, the heteroaryl group is substituted at the third position and/or the fourth position, the total number of the substituents is generally not larger than 3 and, preferably, not larger than 2.

There is no particular limitation on the substituted or unsubstituted adamantane ring, substituted or unsubstituted bicyclononane ring or substituted or unsubstituted norbornane ring formed by the groups R2 and R3 that are coupled together. Preferably, however, there is used a 2-adamantane ring, a bicyclo[3,1,1]-9-nonane ring or a 2-norbornane ring. Preferred substituents of the substituted adamantane ring, substituted bicyclononane ring or substituted norbornane ring will be the same as the preferred substituents of the substituted aryl group. There is no particular limitation on the position of the substituent of the substituted adamantane ring, substituted bicyclononane ring or substituted norbornane ring or on the number of the substituents. From the standpoint of easy synthesis, however, it is desired to use the ring in an unsubstituted form.

The substituent R4 in the above-mentioned general formula (1) is the one at the seventh position, eighth position, ninth position or tenth position of the naphthopyrane ring. This substituent is usually introduced in order to adjust a maximum absorption wavelength that affects the tone of color developed by the chromene compound of the present invention. In the present invention, therefore, an optimum substituent is selected depending upon a desired tone of color.

Though there is no particular limitation on the substituent R4, there can be used the same substituents as those of the above-mentioned substituted or unsubstituted aryl group. Particularly preferred examples of the substituent R4 include alkyl group, aryl group, halogen atom, aralkyl group and alkoxyl group. As the alkyl group, there can be generally used the one having 1 to 4 carbon atoms though there is no particular limitation on the number of carbon atoms. Preferred examples Of the alkyl group include methyl group, ethyl group, propyl group and butyl group. Though there is no particular limitation on the number of carbon atoms of the aryl group, it is generally desired that the aryl group has 6 to 10 carbon atoms. Preferred examples of the aryl group include phenyl group and naphthyl group. As the halogen Atom, there can be used a fluorine atom, a chlorine atom, a bromine atom or an iodine atom. Though there is no particular limitation on the number of carbon atoms of the aralkyl group, it is generally desired to use an aralkyl group having 7 to 11 carbon atoms. Preferred examples of the aralkyl group include benzyl group, phenylethyl group, phenylpropyl group and phenylbutyl group. Though there is no particular limitation on the number of carbon atoms of the alkoxyl group, it is generally desired to use an alkoxyl group having 1 to 5 carbon atoms. Preferred examples of the alkoxyl group include methoxy group, ethoxyl group, n-propoxy group, isopropoxy group, n-butoxy group, sec-butoxy group and t-butoxy group.

In the general formula (1), n is the number of the substituents R4 and is an integer of 0 to 4. The value n may be from 0 to 4. For easy synthesis, however, n is preferably not larger than 3 and, more preferably, not larger than 2. When n is not smaller than 2, the substituents R4 may be the same ones or the different ones.

In the general formula (1), R5 is a hydrogen atom or a substituent. There is no particular limitation when R5 is a substituent. In this case, the substituent R5 is the same as the substituent R4. From the standpoint of suppressing color due to aging, however, it is desired that R5 is a hydrogen atom.

In the general formula (1), when R1 is an alkyl group in which a carbon atom bonded to the naphthopyrane ring is a primary carbon atom, R2 and R3 are groups represented by the following formula (2), ##STR8##

wherein X is an oxygen atom or a sulfur atom, or groups represented by the following formula (3), ##STR9##

wherein R6 is an alkoxyl group or a trifluoromethoxy group, and k is 0 or 1, which may be different from each other, and at least either one of them is a group represented by the above formula (3), and R5 is a hydrogen atom.

The above formula (2) Represents a 2-thienyl group or a 2-furanyl group. From the standpoint of color density, the furanyl group is preferred since it develops color of a high density. From the standpoint of initial color (color of before being irradiated with light containing ultraviolet rays), on the other hand, the thienyl group is preferred since it initially develops less color.

In the above-mentioned formula (3), the substituent R6 is an alkoxyl group or a trifluoromethoxy group. As the alkoxyl group, it is desired to use an alkoxyl group having 1 to 5 carbon atoms and, particularly, an alkoxyl group having 1 to 2 carbon atoms from the standpoint of easy synthesis.

Preferred examples of the alkoxyl group used in the present invention include methoxy group and ethoxy group. As the substituent R6, an alkoxyl group is preferred since it enables the fading rate to be increased.

When the group represented by the above formula (3) has a fluorine atom as a substituent, it is desired that the fluorine atom is substituted at a position neighboring the substituent R6 (ortho position relative to R6) in order to decrease the initial color, though there is no particular limitation on the position at where the fluorine atom is substituted.

Preferred examples of the group of the formula (3) include 4-methoxyphenyl group, 4-methoxy-3-fluorophenyl group, 4-ethoxyphenyl group and 4-trifluorophenyl group. It is desired that the combination of R2 and R3 is represented by the above-mentioned formula (3) from the standpoint of durability in the photochromic property.

Among the chromene compounds of the present invention, it is desired to use chromene compounds represented by the following formulas since they can be synthesized maintaining a good yield and exhibit small changes in the color after the coloring-fading cycles are repeated, ##STR10##

wherein

R1 is a methyl group or an ethyl group, R2 and R3 are thienyl groups or groups represented by the following formula (3), ##STR11##

wherein R6 is an alkoxyl group or a trifluoromethoxy group, and k is 0 or 1, wherein R2 and R3 may be different from each other, but at least either R2 or R3 is a group represented by the above formula (3), and R4 and n are as defined in the above-mentioned formula (1), ##STR12##

wherein R1 is an alkyl group having 3 to 15 carbon atoms and in which a carbon atom bonded to the naphthopyrane ring is a secondary carbon atom or a tertiary carbon atom, R2 and R3 are aryl groups having 6 to 14 carbon atoms which may be different from each other, R4 is a group selected from alkyl group, alkoxyl group, aryl group, acyloxyl group and hydroxyl group, n is an integer of 0 to 2 and when n is 2, R4 may be the same or different groups, ##STR13##

R1 is an alkyl group having 3 to 15 carbon atoms and in which a carbon atom bonded to the naphthopyrane ring is a secondary carbon atom or a tertiary carbon atom, and R2 and R3 are substituted or unsubstituted heteroaryl groups having 4 to 12 carbon atoms which may be different from each other, ##STR14##

wherein R1 is an alkyl group having 3 to 15 carbon atoms and in which a carbon atom bonded to the naphthopyrane ring is a secondary carbon atom or a tertiary carbon atom, R2 is a substituted or unsubstituted heteroaryl group having 4 to 12 carbon atoms, and R3 is a substituted aryl group having 6 to 14 carbon atoms, ##STR15##

wherein R1 is an alkyl group having 3 to 15 carbon atoms and in which a carbon atom bonded to the naphthopyrane ring is a secondary carbon atom or a tertiary carbon atom, R2 and R3 form a substituted or unsubstituted norbornane ring having 7 to 13 carbon atoms by being coupled to each other, R4 is a group selected from alkyl group, alkoxyl group, aryl group, acyloxyl group and hydroxyl group, n is an integer of 0 to 2 and when n is 2, R4 may be the same or different groups, ##STR16##

wherein R1 is an alkyl group having 3 to 15 carbon atoms and in which a carbon atom bonded to the naphthopyrane ring is a secondary carbon atom or a tertiary carbon atom, R2 and R3 form a substituted or unsubstituted bicyclononane ring having 9 to 15 carbon atoms by being coupled to each other, R4 is a group selected from alkyl group, alkoxyl group, aryl group, acyloxyl group and hydroxyl group, n is an integer of 0 to 2 and when n is 2, R4 may be the same or different groups, and ##STR17##

wherein R1 is an alkyl group having 3 to 15 carbon atoms and in which a carbon atom bonded to the naphthopyrane ring is a secondary carbon atom or a tertiary carbon atom, R2 and R3 form a substituted or unsubstituted adamantane ring having 10 to 16 carbon atoms by being coupled to each other, R4 is a group selected from alkyl group, alkoxyl group, aryl group, acyloxyl group and hydroxyl group, n is an integer of 0 to 2 and when n is 2, R4 may be the same or different groups.

Furthermore, there can be used the chromene compounds represented by the following formulas since they can be synthesized maintaining a good yield, exhibit a small change in the developed color after the coloring-fading cycles and exhibit large fading rates, ##STR18##

wherein R4, R6, k and n are as defined in the above-mentioned formulas (1) and (3), ##STR19##

wherein R1 is an isopropyl group or a t-butyl group, R2 and R3 are substituted aryl groups having 6 to 14 carbon atoms which may be different from each other, R4 is a group selected from alkyl group, alkoxyl group, aryl group, acyloxyl group and hydroxyl group, and n is an integer of 0 to 2 and when n is 2, R4 may be the same or different groups, ##STR20##

wherein R1 is an isopropyl group or a t-butyl group, and R2 and R3 are substituted or unsubstituted heteroaryl groups having 4 to 12 carbon atoms which may be different from each other, ##STR21##

wherein R1 is an isopropyl group or a t-butyl group, R2 is a substituted or unsubstituted heteroaryl group having 4 to 12 carbon atoms, and R3 is a substituted aryl group having 6 to 14 carbon atoms, ##STR22##

wherein R1 is an isopropyl group or a t-butyl group, R2 and R3 form a substituted or unsubstituted norbornane ring having 7 to 13 carbon atoms by being coupled to each other, R4 is a group selected from alkyl group, alkoxyl group, aryl group, acyloxyl group and hydroxyl group, and n is an integer of 0 to 2 and when n is 2, R4 may be the same or different groups, ##STR23##

wherein R1 is an isopropyl group or a t-butyl group, R2 and R3 form a substituted or unsubstituted bicyclononane ring having 9 to 15 carbon atoms by being coupled to each other, R4 is a group selected from alkyl group, alkoxyl group, aryl group, acyloxyl group and hydroxyl group, and n is an integer of 0 to 2 and when n is 2, R4 may be the same or different groups,

and ##STR24##

wherein R1 is an isopropyl group or a t-butyl group, R2 and R3 form a substituted or unsubstituted adamantane ring having 10 to 16 carbon atoms by being coupled to each other, R4 is a group selected from alkyl group, alkoxyl group, aryl group, acyloxyl group and hydroxyl group, and n is an integer of 0 to 2 and when n is 2, R4 may be the same or different groups.

Concrete examples of the chromene compound that can be favorably used in the present invention include:

1) 5-methyl-2,2-bis(4-methoxyphenyl)-2H-benzo(h) chromene;

2) 5-methyl-2,2-bis(3-fluoro-4-methoxyphenyl)-2H-benzo(h) chromene;

3) 5-ethyl-2,2-bis(4-methoxyphenyl)-2H-benzo(h) chromene;

4) 5-methyl-2,2-bis(4-methoxyphenyl)-2H-benzo(h) chromene;

5) 5-methyl-2-(4-methoxyphenyl)-2-(4-trifluoromethoxyphenyl)-2H-benzo(h) chromene;

6) 5-methyl-2-(2-furyl)-2-(3-fluoro-4-methoxyphenyl)-2H-benzo(h) chromene;

7) 5-methyl-2-(2-thienyl)-2-(4-methoxyphenyl)-2H-benzo(h) chromene;

8) 7-methoxy-5-methyl-2,2-bis(4-methoxyphenyl)-2H-benzo(h) chromene;

9) 5-methyl-2-(4-methoxyphenyl)-2-(3-fluoro-4-methoxyphenyl)-2H-benzo(h) chromene;

10) 5-n-propyl-2,2-bis(4-methoxyphenyl)-2H-benzo(h) chromene;

11) 5-tert-butyl-2,2-diphenyl-2H-benzo(h) chromene;

12) 5-tert-butyl-2-bicyclo[3.3.1]nonane-2H-benzo(h) chromene;

13) 5-tert-pentyl-2-(2-furyl)-2-(4-methoxyphenyl)-2H-benzo(h) chromene

14) 5-sec-butyl-2-(3-cyano-4-methoxyphenyl)-2-(4-methoxyphenyl)-2H-benzo(h) chromene;

15) 5-(1-ethyl-1-methylpropyl)-2,2-bis(3-fluoro-4-methoxyphenyl)-2H-benzo h) chromene;

16) 5-t-butyl-2-phenyl-2-(2-thienyl)-2H-benzo(h) chromene;

17) 5-isopropyl-2-(2-naphthyl)-2-(phenyl)-2H-benzo(h) chromene;

18) 8-methoxy-2-(2-N-methylpyryl)-2-phenyl-5-(2-phenyl-1-methyl ethyl)-2H-benzo(h) chromene;

19) 8-hydroxy-5-isopropyl-2,2-bis(2-thienyl)-2H-benzo(h) chromene;

20) 8-acetoxy-5-isopropyl-2,2-bis(4-methylphenyl)-2H-benzo(h) chromene;

21) 5-isopropyl-2,2-diphenyl-2H-benzo(h) chromene;

22) 5-isopropyl-2,2-bis(3-fluoro)-4-methoxyphenyl)-2H-benzo(h) chromene;

23) 5-isopropyl-2-(4-methoxyphenyl)-2-(4-trifluoromethoxyphenyl)-2H-benzo(h) chromene;

24) 5-isopropyl-2-phenyl-2-(4-trifluoromethoxyphenyl)-2H-benzo(h) chromene; and

25) 5-isopropyl-2,2-bis(4-methoxyphenyl)-2H-benzo(h) chromene.

The chromene compound represented by the above-mentioned general formula (1) of the present invention usually exists in the form of a colorless or pale yellow solid or a viscous liquid at normal temperature under normal pressure, and can be confirmed by means (a) to (c) described below.

(a) Measurement of the proton nucleus magnetic resonance spectrum (.sup.1 H-NMR) indicates peaks near .delta.5.5 to 9.0 ppm due to an aromatic proton and a proton of an alkene, and peaks near .delta.1.0 to 4.0 ppm due to protons of an alkyl group and an alkylene group. Upon relatively comparing the spectral intensities, furthermore, it is possible to know the number of protons of the bonded groups.

(b) The composition of a corresponding product can be determined based on the elemental analysis.

(c) Measurement of the .sup.13 C-nuclear magnetic resonance spectrum (.sup.13 C-NMR) indicates a peak near .delta.110 to 160 ppm based on a carbon atom of an aromatic hydrocarbon group, a peak near .delta.80 to 140 ppm due to a carbon atom of an alkene, and peaks near .delta.20 to 80 ppm due to carbon atoms of an alkyl group and an alkylene group.

The chromene compound represented by the above-mentioned general formula (1) of the present invention can be synthesized by any method without any particular limitation. A representative method that is generally preferably employed will be described below.

A compound of the present invention represented by the general formula (1) wherein R1 is an alkyl group in which a carbon atom bonded to the naphthopyane ring is a primary carbon atom can be produced by, for example, the following process A.

Process A

A naphthol derivative represented by the following general formula (4), ##STR25##

wherein R1 is an alkyl group in which a carbon atom bonded to the naphthopyrane ring is a primary carbon atom, and R4 and n are as defined in the general formula (1),

is reacted with a propargyl alcohol derivative represented by the following general formula (5), ##STR26##

wherein R2 and R3 are as defined in the general formula (1), in the presence of an acid catalyst.

There is no particular limitation on the methods of synthesizing the compounds represented by the above-mentioned general formulas (4) and (5). The naphthol derivative represented by the above-mentioned general formula (4) can be synthesized by, for example, reacting an o-bromoacetophenone and a propyne derivative at 10 to 160.degree. C. for 10 minutes to 2 hours, and adding a potassium hexamethyldisilazide (KHMDS) at -78.degree. C., followed by heating at 75.degree. C. for 30 minutes to 2 hours. In this case, when an o-bromoacetophenone is used having substituents at the second position, third position, fourth position and fifth position, there can be synthesized a chromene compound having substituents at the tenth position, ninth position, eighth position and seventh position of the naphthopyrane ring.

Furthermore, the propargyl alcohol derivative represented by the above-mentioned general formula (5) can be synthesized by, for example, reacting a ketone derivative corresponding to the above-mentioned general formula (5) with a metal acetylene compound such as lithium acetylide.

The reaction of the compound represented by the above-mentioned general formula (4) with the compound represented by the above-mentioned general formula (5) is usually carried out as described below. That is, the reaction ratio of these two kinds of compounds is selected from a wide range, but is generally selected from a range of 1:10 to 10:1 (molar ratio). As the acid catalyst, furthermore, there is used sulfuric acid, benzenesulfonic acid, p-toluenesulfonic acid or acidic alumina in an amount of from 0.1 to 10 parts by weight with respect to the sum of 100 parts by weight the reaction substrates represented by the above-mentioned general formulas (4) and (5). The reaction temperature is, usually, from 0 to 200.degree. C. As the solvent, there is used a non-protonic organic solvent such as N-methylpyrrolidone, dimethylformamide, tetrahydrofuran, benzene or toluene.

A compound of the present invention represented by the general formula (1) wherein R1 is an alkyl group in which a carbon atom bonded to the naphthopyane ring is a secondary carbon atom or a tertiary carbon atom, and R2 and R3 are aryl groups or heteroaryl groups, can be produced by, for example, the following process B.

Process B

A naphthol derivative represented by the following general formula (4'), ##STR27##

wherein R1 is an alkyl group in which a carbon atom bonded to the naphthopyrane ring is a secondary carbon atom or a tertiary carbon atom, and R4, R5 and n are as defined in the general formula (1), is reacted with a propargyl alcohol represented by the following general formula (5), ##STR28##

wherein R2 and R3 are as defined in the general formula (1), in the presence of an acid catalyst.

There is no particular limitation on the methods of synthesizing the compounds represented by the above-mentioned general formulas (4') and (5). The naphthol derivative represented by the above-mentioned general formula (4') can be synthesized by, for example, reacting a phenylacetyl chloride and an acetylene derivative at 180.degree. C. followed by hydrolysis. In this case, when a phenylacetyl chloride is used having substituents at the second position, third position, fourth position and fifth position, there can be synthesized a chromene compound having substituents at the tenth position, ninth position, eighth position and seventh position of the naphthopyrane ring.

Furthermore, the propargyl alcohol derivative represented by the above-mentioned general formula (5) can be synthesized by, for example, reacting a ketone derivative corresponding to the above-mentioned general formula (5) with a metal acetylene compound such as lithium acetylide.

The reaction of the compound represented by the above-mentioned general formula (4') with the compound represented by the above-mentioned general formula (5) is usually carried out as described below. That is, the reaction ratio of these two kinds of compounds is selected from a wide range, but is generally selected from a range of 1:10 to 10:1 (molar ratio). As the acid catalyst, furthermore, there is used sulfuric acid, benzenesulfonic acid, p-toluenesulfonic acid or acidic alumina in an amount of from 0.1 to 10 parts by weight with respect to the sum of the reaction substrates represented by the above-mentioned general formulas (4') and (5). The reaction temperature is, usually, from 0 to 200.degree. C. As the solvent, there is used a non-protonic organic solvent such as N-methylpyrrolidone, dimethylformamide, tetrahydrofuran, benzene or toluene.

A compound of the present invention represented by the general formula (1) wherein R2 and R3 are coupled to each other to form an adamantane ring, a bicyclononane ring or a norbornane ring, can be produced by, for example, the following process C.

Process C

A naphthol derivative represented by the following general formula (4'), ##STR29##

wherein R1, R4, R5 and n are as defined in the general formula (1), is reacted with an aldehyde derivative represented by the following general formula (6), ##STR30##

wherein R2 and R3 form an adamantane ring, a bicyclononane ring or a norbornane ring as defined in the general formula (1), in the presence of a metal alkoxide.

There is no particular limitation on the method of synthesizing the compound represented by the above-mentioned general formula (6). That is, the aldehyde derivative represented by the above-mentioned general formula (6) can be synthesized by, for example, reacting a Schiff base obtained from an acetaldehyde and a cyclohexylamine with a lithium diisopropylamide, followed by the reaction with a ketone derivative having a substituent corresponding to the above general formula (6).

Thereafter, the reaction is carried out in an aqueous solution of an oxalic acid.

The reaction of the compound represented by the above-mentioned general formula (4') with the compound represented by the above-mentioned general formula (6) is usually carried out as described below. That is, the reaction ratio of these two kinds of compounds is selected from a wide range, but is generally selected from a range of 1:10 to 10:1 (molar ratio). As the metal alkoxide, furthermore, there is used a tetraethoxytitanic acid or the like acid in an amount of from 0.25 to 10 parts by weight with respect to the compound represented by the above-mentioned general formula (4'). The reaction temperature is, usually, from 0 to 200.degree. C. As the solvent, there is used a non-protonic organic solvent such as N-methylpyrrolidone, dimethylformamide, tetrahydrofuran, benzene or toluene.

The chromene compound of the present invention represented by the above-mentioned general formula (1) dissolves well in a general organic solvent such as toluene, chloroform or tetrahydrofurane. When the chromene compound of the present invention represented by the above-mentioned general formula (1) is dissolved in such a solvent, the solution is generally nearly colorless and transparent. When irradiated with sunlight or ultraviolet rays, however, the solution readily develops color and returns back to its initial colorless state when light is shut off; i.e., the solution exhibits a favorable and reversible photochromic action. The photochromic fluid can be used for such applications as ornamental uses.

The chromene compounds of the present invention represented by the general formula (1) can be used in a single kind or being mixed together in two or more kinds depending upon the purpose of use. Furthermore, the chromene compounds of the present invention can be combined together with other chromene compounds to obtain a chromene composition exhibiting more excellent photochromic properties.

As the other chromene compound to be used in combination, there can be favorably used a chromene compound represented by the following general formula (7), ##STR31##

wherein R7 is AN AMINO GROUP represented by the following formula (8), ##STR32##

wherein R11 and R12 are hydrogen atoms, substituted or unsubstituted alkyl groups having 1 to 10 carbon atoms, or substituted or unsubstituted aromatic hydrocarbon groups or heterocyclic groups having 6 to 10 carbon atoms, which may be different from each other,

or a substituted or unsubstituted heterocyclic group having a nitrogen atom as a hetero atom and in which the nitrogen atom is bonded to the naphthopyrane ring, or a condensed heterocyclic group formed by the condensation of the above heterocyclic group with an aromatic hydrocarbon ring or an aromatic heterocyclic ring,

R8 and R9 are substituted or unsubstituted aromatic hydrocarbon groups, substituted or unsubstituted aromatic heterocyclic groups or alkyl groups, which may be different from each other,

R10 is a substituent, and

m is an integer of 0 to 4 representing the number of the substituents R10 and when m is not smaller than 2, R10 may be the same or different groups.

When the chromene compound represented by the general formula (7) is used alone, a high color-developing sensitivity is obtained and a high fading rate is obtained accompanied, however, by a large initial color and a large degree of coloring after aged. By mixing the chromene compound of the general formula (7) to the chromene compound represented by the general formula (1), however, the initial color can be decreased and color due to aging can be decreased, too, though the color-developing sensitivity decreases to some extent.

In the above-mentioned general formula (7), R7 is an amino group represented by the above formula (8) or a substituted or unsubstituted heterocyclic group having a nitrogen atom as a hetero atom and in which the nitrogen atom is bonded to the naphthopyrane ring, or a condensed heterocyclic ring formed by the condensation of the above heterocyclic group with an aromatic hydrocarbon ring or an aromatic heterocyclic ring.

As the substituted or unsubstituted alkyl group having 1 to 10 carbon atoms or as the substituted or unsubstituted aromatic hydrocarbon group or heterocyclic group having 6 to 10 carbon atoms represented by R11 and R12 in the above-mentioned formula (8), there can be used any known group without any particular limitation. As the alkyl group, aromatic hydrocarbon group or heterocyclic group, there can be used an alkyl group having 1 to 4 carbon atoms, a benzene ring or a naphthalene ring, As the substituent for the alkyl group, aromatic hydrocarbon group or heterocyclic group, furthermore, there can be used a hydroxyl group, a cyano group or a halogen atom.

Concrete examples of the amino group represented by the above formula (8) include methylamino group, ethylamino group, propylamino group, isopropylamino group, dimethylamino group, diethylamino group, dipropylamino group, methylethylamino group, 2-hydroxyethylamino group, di(hydroxyethyl)amino group, di(cyanomethyl)amino group and diphenylamino group. The substituents R11 and R12 may be the same or different.

Referring to the substituted or unsubstituted heterocyclic group having a nitrogen atom as a hetero atom and in which the nitrogen atom is bonded to the naphthopyrane ring or the condensed heterocyclic group formed by the condensation of the above heterocyclic group with an aromatic hydrocarbon ring or an aromatic heterocyclic ring, represented by R7 in the general formula (7), it is desired that the number of carbon atoms constituting the heterocyclic group is from 2 to 10 and, more preferably, from 2 to 6. The ring may contain a hetero atom in addition to the nitrogen atom bonded to the naphthopyrane ring. Though there is no limitation, it is desired that the hetero atom is an oxygen atom, a sulfur atom or a nitrogen atom. AS the aromatic hydrocarbon ring or the aromatic heterocyclic ring to be condensed with the heterocyclic group, there can be used an aromatic hydrocarbon ring or an aromatic heterocyclic ring having 6 to 10 carbon atoms, which will be a benzene ring, a thiophene ring or a furan ring. As the substituted or unsubstituted heterocyclic ring having the nitrogen atom as a hetero atom and which is bonded to the naphthopyrane ring through the nitrogen atom, or as the condensed heterocyclic group formed by the condensation of the above heterocyclic group with an aromatic hydrocarbon ring or an aromatic heterocyclic ring, there can be exemplified pyrrolidinyl group, piperidino group, hexamethyleneimino group, 2,2,6,6-tetramethylpiperidino group, morpholino group, 2,6-dimethylmorpholino group, N-methylpiperadinyl group, thiomorpholino group, indolyl group, methylindolyl group, tetrahydroquinolyl group and aziridinyl group.

In the above-mentioned general formula (7), R8 and R9 are substituted or unsubstituted aromatic hydrocarbon groups, substituted or unsubstituted aromatic heterocyclic groups or alkyl groups, which may be different from each other.

Though there is no particular limitation on the aromatic hydrocarbon group, it is generally desired to use an aromatic hydrocarbon group having 6 to 10 carbon atoms. Concrete examples of the aromatic hydrocarbon group include phenyl group, 2-naphthyl group and 1-naphthyl group.

Though there is no particular limitation on the aromatic heterocyclic group, it is generally desired to use an aromatic heterocyclic group having 3 to 20 carbon atoms and, preferably, 3 to 12 carbon atoms. There is no particular limitation on the hetero atom contained in the aromatic heterocyclic group. Preferably, however, the hetero atom is an oxygen atom, a sulfur atom or a nitrogen atom, and its number is from 1 to 3 and, preferably from 1 to 2. When hetero atoms are contained in a plural number in the aromatic heterocyclic group, those hetero atoms may be of the same kind or of different kinds. Moreover, the aromatic heterocyclic group may be ring-condensed with an aromatic ring. As the aromatic ring which may be ring-condensed, there can be used an aromatic ring having 6 to 10 carbon atoms, such as benzene ring or naphthalene ring. Concrete examples of the aromatic heterocyclic group include furyl group, thienyl group, pyrrolyl group, benzofuryl group, indole group, quinolyl group, isoquinolyl group, dibenzofuryl group and carbazole group.

Though there is no particular limitation, the alkyl group generally has 1 to 5 carbon atoms and, preferably, 1 to 3 carbon atoms. Concrete examples of the alkyl group include methyl group, ethyl group, n-propyl group and isopropyl group. By taking the practicable durability into consideration, the methyl group is most preferred.

The aromatic hydrocarbon group and aromatic heterocyclic group represented by R8 and R9 may have any known substituent, and there is no limitation on the kind thereof. Preferably, however, there can be used alkyl group, alkoxyl group, alkoxyalkoxyl group, aryloxyl group, alkoxyalkyl group, aralkyl group, substituted amino group, substituted or unsubstituted heterocyclic group having a nitrogen atom as a hetero atom and in which the nitrogen atom is bonded to the aromatic hydrocarbon group and to the aromatic heterocyclic group, acyloxyl group, hydroxyl group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, halogen atom, cyano group, trifluoromethyl group, trifluoromethoxy group and nitro group. There is no particular limitation on the positions and the numbers of the substituents bonded to the aromatic hydrocarbon group and to the aromatic heterocyclic group. Preferably, however, the number of the substituents is 0 to 4 and, preferably, 0 to 3. These substituents may be of the same kind or may be of different kinds and may be used in combination without any limitation.

There is no particular limitation on the alkyl group which is a substituent for the aromatic hydrocarbon group or the aromatic heterocyclic group represented by R8 and R9. Generally, however, the alkyl group has 1 to 10 carbon atoms and, preferably, 1 to 4 carbon atoms. Concrete examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group and t-butyl group.

Though there is no particular limitation, the alkoxyl group generally has 1 to 10 carbon atoms and, preferably, 1 to 4 carbon atoms. Concrete examples of the alkoxyl group include methoxy group, ethoxyl group, n-propoxyl group, isopropoxyl group, n-butoxy group and t-butoxy group.

Though there is no particular limitation, the alkoxyalkoxyl group generally has 2 to 20 carbon atoms and, preferably, 3 to 10 carbon atoms. Concrete examples of the alkoxyalkoxyl group include methoxyethoxyl group, ethoxyethoxyl group, methoxypropoxyl group and methoxybutoxy group.

Though there is no particular limitation, the aryloxyl group generally has 6 to 14 carbon atoms and, preferably, 6 to 10 carbon atoms. Concrete examples of the aryloxyl group include phenoxy group, 1-naphthoxy group and 2-naphthoxy group.

Though there is no particular limitation, the alkoxyalkyl group generally has 2 to 10 carbon atoms and, preferably, 2 to 6 carbon atoms. Concrete examples of the alkoxyalkyl group include methoxymethyl group, ethoxymethyl group, propoxymethyl group, dimethoxymethyl group, 2,2-dioxacyclopentane-1-il group and butoxymethyl group.

Though there is no particular limitation, the aralkyl group generally has 7 to 16 carbon atoms and, preferably, 7 to 10 carbon atoms. Concrete examples of the aralkyl group include benzyl group, phenylethyl group, phenylpropyl group and phenylbutyl group.

Though there is no particular limitation, the acyloxyl group generally has 1 to 15 carbon atoms and, preferably, 1 to 6 carbon atoms. Concrete examples of the acyloxyl group include acetoxyl group, propionyloxy group, butyryloxy group, (meth)acryloyloxy group and benzoyloxy group.

Though there is no particular limitation, the substituted amino group generally has a substituent such as an alkyl group with 1 to 10 carbon atoms, or a hydroxy-substituted alkyl group. Concrete examples of the substituted amino group include methylamino group, ethylamino group, propylamino group, isopropylamino group, dimethylamino group, diethylamino group, dipropylamino group, methylethylamino group, 2-hydroxyethylamino group and di(hydroxyethyl)amino group.

Referring to the substituted or unsubstituted heterocyclic group having a nitrogen atom as a hetero atom and in which the nitrogen atom is bonded to the aromatic hydrocarbon group and to the aromatic heterocyclic group, it is desired that the number of carbon atoms constituting the heterocyclic group is from 2 to 10 and, preferably, from 2 to 6. The ring may contain a hetero atom in addition to the nitrogen atom bonded to the aromatic hydrocarbon group and to the aromatic heterocyclic group. Though there is no particular limitation, it is desired that the hetero atom is an oxygen atom, a sulfur atom or a nitrogen atom. As the substituted or unsubstituted heterocyclic group having the nitrogen atom as a hetero atom and in which the nitrogen atom is bonded to the aromatic hydrocarbon group and to the aromatic heterocyclic group, there can be exemplified pyrrolidinyl group, piperidino group, hexamethyleneimino group, 2,2,6,6-tetramethylpiperidino group, morpholino group,2,6-dimethylmorpholino group, N-methylpiperadinyl group and thiomorpholino group.

Though there is no particular limitation, the alkoxycarbonyl group generally has 1 to 10 carbon atoms and, preferably, 1 to 7 carbon atoms. Concrete examples of the alkoxycarbonyl group include methoxycarbonyl group, ethoxycarbonyl group, (iso)propoxycarbonyl group, and (iso, t-)butyloxycarbonyl group.

Though there is no particular limitation on the aryloxycarbonyl group, the aryl group is an aryloxy group having generally 6 to 14 carbon atoms and, preferably, 6 to 10 carbon atoms. Concrete examples of the aryloxycarbonyl group include phenoxycarbonyl group, 1-naphthoxycarbonyl group and 2-naphthoxycarbonyl group.

Though there is no particular limitation, the acyl group generally has 1 to 15 carbon atoms and, preferably, 1 to 7 carbon atoms. Concrete examples of the acyl group include formyl group, acetyl group, propionyl group, butylyl group and benzoyl group.

Though there is no particular limitation, the halogen atom is generally a fluorine atom, a chlorine atom, a bromine atom or an iodine atom.

In the above-mentioned general formula (7), R10 is a substituent substituted for the seventh position, eighth position, ninth position and tenth position of the naphthopyrane ring. Introduction of the substituent does not seriously affect the effect of the present invention. As the substituent, there can be used alkyl group, alkoxyl group, aralkyl group, acyl group, alkoxycarbonyl group, substituted amino group, substituted or unsubstituted heterocyclic group having a nitrogen atom as hetero atom and in which the nitrogen atom is bonded to the naphthopyrane ring, aromatic hydrocarbon group, acyloxyl group, nitro group, hydroxyl group or halogen atom. As the aromatic hydrocarbon group, though there is no particular limitation on the number of carbon atoms, it is desired to use an aromatic hydrocarbon group having 6 to 14 carbon atoms. Preferred examples of the aromatic hydrocarbon group include phen