GB2267287A

GB2267287A - Optical sensitising dyes

Info

Publication number: GB2267287A
Application number: GB9207519A
Authority: GB
Inventors: Malcolm David Tirel; William Edward Long
Original assignee: Ilford Ltd
Current assignee: Ilford Imaging UK Ltd
Priority date: 1992-04-07
Filing date: 1992-04-07
Publication date: 1993-12-01
Anticipated expiration: 2012-04-07
Also published as: GB9207519D0; GB2267287B

Abstract

These are described N-sulphonated optical sensitising dyes of the general formula I. <IMAGE> in which Dye represents the chromophoric residue of photographic sensitising dye, L represents alkylene and R represents a substituent group, which may be joined to L to form a ring system or systems, and n is 1 or 2, X is a counter ion and m is 0 or 1.

Description

This invention relates to novel chemical compounds, to their production, and to their use as optical sensitisers for photographic materials.

According to the present invention there are provided N-sulphonated compounds of the general formula I:

in which Dye represents the chromophoric residue of a photographic sensitising dye, L represents alkylene and R represents a substituent group, which may be joined to L to form a ring system or systems, and n is 1 or 2, X is a counter ion and m is O or 1.

Examples of substituent groups R are lower alkyl groups having from 1 to 6 carbon atoms and in particular methyl, ethyl or propyl groups or a phenyl group. Examples of rings in which R is linked to L include piperidine and pyrrolidine rings.

The linking group L is an alkylene chain with up to 6 carbon atoms which may be branched or joined with R. Examples of suitable alkylene chains for L are ethylene, 1, 2-propylene and 1, 3-propylene.

Examples of suitable chromophoric dye groups are dyes of the cyanine class, which may be monomethine, trimethine, pentamethine or heptamethine cyanine dyes, and dyes of the merocyanine class. The group L is linked to the dye chromophore through a suitable heteroatom, and in particular through a nitrogen atom which forms part of a heterocyclic ring system or systems. Examples of suitable counter ions X include hydrogen ions, alkali metal ions such as sodium or potassium, and ammonium ions such as triethyl ammonium.

Suitable dyes of the cyanine class have the following general formula II4-

in which R and L have the meanings assigned above, R1 is a substituent, R2, R3 and R4 are H or substituents, p is 0, 1, 2, or 3, and the groups A and B represent the atoms necessary to complete a heterocyclic ring system or systems, which may be substituted.

The substituent R1 can be a group L

a lower alkyl group, or a substituted lower alkyl group which is substituted by another alkyl group, a halogen atom or atoms, a carboxylic acid, ester, or amide group, or a sulphonic acid or amide group. Suitable substituents R2, R3 and R4 are lower alkyl, lower alkoxy, lower alkylthio, halogen dialkylamino, and aromatic or heterocyclic rings. Alternatively two of R2, R3 and R4 may be joined to form a ring.Suitable heterocyclic rings represented by the groups A and B, which may be the same or different, include benzoxazole, benzimidazole, benzothiazole, benzoselenazole, indole, quinoline, thiazole, thiazolidine, or pyrrole rings, which may be substituted by lower alkyl, lower dialkylamino, lower alkoxy, lower alkyl thio, an aromatic or heterocyclic ring, halogen, cyano, or trifluoromethyl, or may be further annelated to give, for example, a naphthothiazole ring.

Suitable dyes of the merocyanine class have the following general formula III:

in which R, L, A, X, m, R2 and R3 have the meanings assigned above, q is O or 1, and Y and Z are CN or carbonyl containing groups, or Y and Z together are combined to form a ring which contains a carbonyl group.

Preferably Y and Z represent a hydantoin, thiohydantoin, or rhodanine ring.

A second feature of the present invention relates to novel intermediate compounds of formula (IV):-

in which A, R, and L have the meanings' assigned above, and G is a lower alkyl group or a leaving group, or is a group containing a leaving group. Suitable leaving groups G are lower alkyl thio groups, lower alkoxy groups or halogen. Particularly suitable lower alkyl groups in formula IV are methyl groups.

Thenovel intermediates of formula IV may be prepared by reaction of a heterocycle of formula V:

in which A and G have the meanings assigned above with a 1, 2, 3oxathiazolidine -S,-S-dioxide or tetrahydro 1, 2, 3 oxathiazine S, S-dioxide of formula VI

in which R and L have the meanings assigned above. Compounds of formula VI may be prepared by known routes, and in particular by the route described in Journal of Organic Chemistry, 1991, vol 56, p 3177 involving the reaction of an alkanolamine of formula VII with thionyl chloride, and oxidation to give a compound of formula VI

Examples of intermediate compounds of formula VI include compounds 1, 2, 3, and 4.

Compound 1 Compound 2

Compound 3 Compound 4

Examples of heterocyclic compounds which may be reacted with compounds of formula VI to yield compounds of formula IV include

Examples of compounds of formula IV include

The intermediate compounds of formula (IV) may be converted to the dyes of formula (II) or (III) by known routes, and in particular those described in the book Cyanine Dyes and Related Compounds, by F.M. Hamer, published by Interscience in 1964.

For instance, monomethine cyanine dyes may be prepared by reaction of an intermediate of formula (IV) in which G is methyl with a salt of formula (VIII)

in which R1 and B have the meanings assigned above, and G1 is a leaving group, and especially a methylthio group in the presence of a basic catalyst.

Trimethine dyes of formula (II) may be prepared by reaction of an intermediate of formula (IV) in which G is a lower alkyl group, and especially a methyl group, with an intermediate of formula IX

in which B, R, R3, and R4 have the meanings assigned above, and G2 is a leaving group, and especially aryl amino which may be activated to form a leaving group by reaction with acetic anhydride. Intermediates of type IX are well known to be useful intermediates for the preparation of sensitising dyes.

Merocyanine dyes of. formula (III) may be prepared, for example, by reaction of an intermediate of formula (IV) in which the group G is a leaving group, and especially a methyl thio group with a rhodanine, hydantoin or thiohydantoin compound in the presence of a basic catalyst.

The N-sulphonate dyes of formula I are useful as optical sensitising dyes for photographic silver halide emulsions and are particularly useful as they are relatively soluble in water, which avoids or reduces the need for organic solvents in formulation, and reduces dye-stain in the final photographic image.

The invention includes photographic silver halide emulsions which include at least one dye of formula I and photographic silver halide materials which comprise at least one such emulsion. These emulsions may comprise any silver halide or combinations thereof used for photographic materials as well as additives normally present in such emulsions for example hardeners or stabilisers.

The following Examples will serve to illustrate the invention. Example I relates to the preparation of a sensitising dye of formula I. Example II lists dyes of formula I which have been prepared in a similar manner.

Example I 3-Ethvl 1. 2. 3 - Oxathiazolidine - S - Oxide A solution of thionyl chloride (37.9 ml; 0.52 mol) in CHC13 (40 ml) was added dropwise during lh to a chilled, stirred solution of N-ethylethanolamine (42.15g; 0.473 mol) and triethylamine (138 ml) in CHCl (140 ml) maintaining the internal temperature between 2" and 5".

3 The solution was stirred in an ice-bath for a further 2h, then at room temperature for lh. The solution was washed (H20 x 2; NaHCO3 aq) dried over MgSO4 and evaporated in vacuo to give a brown liquid 44g. This material was distilled and the fraction boiling between 85 -94 at 0.25 mmHg yielded the title compound as a pale yellow liquid 29g (47%).

Nmr (CDC13): = 1.35, t, 3H; 2.90-3.60, m, 4H; 4.20-5.00, m, 2H.

3-Ethvl 1. 2. 3 - Oxathiazolidine - S. S - Dioxide A solution of 3-ethyl 1, 2, 3-oxathiazolidine - S - Oxide (5.00g; 37 mmol) in cold ethyl acetate (25ml) was added to a chilled, stirred solution of sodium periodate (29g; 0.135mol) in water (250ml) containing ruthenium (III) chloride (ca. 20mg). The mixture was stirred in an ice-bath for 1/2 h and extracted (EtOAc; 3x75ml). The combined organic washes were treated with isopropanol (20ml), dried (MgSO4) and filtered through a Kieselguhr pad. The filtrate was evaporated in vacuo to give, as a near colourless liquid, the oxathiazolidine - S, S-dioxide 4.73g (84%) Nmr (CDCl3): = 1.35, t, 3H; 3.20, q, 2H; 3.60, t, 2H; 4.60, t, 2H.

The material was used without further purification.

Green Sensitisina Cvanine dye A mixture of 5, 6 - dichloro - 1 - ethyl - 2 - methylbenzimidazole (0.slug; 2.22 mmol) and 3 - ethyl 1, 2, 3 - oxathiazolidine - S - S dioxide (0.35g; 2.32 mmol) was heated at 1350 for 1/4 h, refluxed with acetone (20ml) for 10 min. The mixture was ground under ether, filtered, washed (ether) and dried in vacuo to yield the quaternary salt as a cream solid 0.58g (69%).

This solid was heated under reflux with 2 - (4-chlorophenylaminovinyl) 3 - ethyl - 5 - methoxybenzoxazolium tosylate (0.80g; 1.60 mmol) in acetonitrile (4 ml), acetic anhydride (0.16 ml) and triethylamine (0.47 ml) during 3/4 h. The mixture was diluted with acetone (6 ml), cooled, filtered, washed (acetone; ether) and dried to give a crimson solid 0.47g. This material was refluxed in acetone (10 ml) for 1/4 h, filtered and dried in vacuo to afford the title dye as a crimson solid 0.42g (45%). M.p. 181-3 (dec). Requires: C=53.7%;' H=5.2%; N=9.6%.

Found: C=53.6%; H=5.1%; N=9.4%.

Summary:

Dye I was dissolved in methyl alcohol added to a photographic silver halide emulsion of the black and white paper type. The emulsion was coated on a paper base. After exposure to a step wedge, silver halide development and fixing the maximum sensitivity was determined.

The maximum sensitivity was 535nm.

Example 2 The following dyes were made as outlined above.

Merocyanine Dye

Dye 2 Monomethine Cyanine Dye

#max (MeOH)=485nn Dye 3 Trimethine Cyanine Dye

max (MeOH) = 483 nm sens max = 525 nm Dye 4 Trinethine Cyanine Dye

#max (Me0H) = 481 nm sens max = 520 nm Dye 5 Trimethine Cyanine Dye ' max (MeOH) = 485 nm sens max = 520 nm

Dye 6 Trimethine Cyanine Dye

#max (Me OH) = 484 nm #max (Me OH) = 484 nm sens max = 520 mm Dye 7 Trimethine Cyanine Dye

ss max (Me OH) = 493 nm sens max = 535 nm Dye 8 Trimethine Cyanine Dye

#max (Me OH) = 485 nm Dye 9 Trimethine Cyanine Dye

max (Me OH) = 543 nm Dye 10 Cyanine

#max (Me OH) = 502 nm Dye 11 Trimethine cyanine dye

Claims

Claims:1. N-sulphonated compounds of the general formula I:

in which Dye represents the chromophoric residue of a photographic sensitising dye, L represents alkylene and R represents a substituent group, which may be joined to L to form a ring system or systems, and n is 1 or 2, X is a counter ion and m is 0 or 1.
2. An N-sulphonated compound according to claim 1 wherein L is ethylene, 1, 2-propylene or 1, 3-propylene.
3. An N-sulphonated compound according to claim 1 wherein R is methyl, ethyl, propyl or an aryl group.
4. An N-sulphonated compound according to claim 1 wherein R is linked to L to form a piperidine or pyrrolidine ring.
5. An N-sulphonated compound according to claim 1 wherein Dye represents the chromophoric residue of a monomethine, trimethine, pentamethine or heptamethine cyanine dye or a merocyanine dye.
6. An N-sulphonated compound according to claim 5 wherein the compound is a cyanine dye of the following general formula II:

in which R and L have the meanings assigned above, R1 is a substituent, R2, R3 and R4 are H or substituents, p is 0, 1, 2, or 3, and the groups A and B represent the atoms necessary to complete a heterocyclic ring system or systems, which may be substituted.
7. An N-sulphonated compound according to claim 6 wherein R1 is a group L

a lower alkyl group, or a substituted lower alkyl group which is substituted by another alkyl group, a halogen atom or atoms, a carboxylic acid, ester, or amide group, or a sulphonic acid or amide group.
8. An N-sulphonated compound according to claim 6 wherein R2, R3 or R 2' 3 4 are lower alkyl, lower alkoxy, lower alkylthio, halogen, dialkylamino, and aromatic or heterocyclic rings or two of R2, R3 and R4 may be joined to form a ring.
9. An N-sulphonated compound according to claim 6 wherein groups A and B may be the same or different, and may be benzoxazole, benzimidazole, benzothiazole, benzoselenazole, indole, quinoline, thiazole, thiazolidine, or pyrrole rings, which may be substituted by lower alkyl, lower dialkylamino, lower alkoxy, lower alkyl thio, an aromatic or heterocyclic ring, halogen, cyano, or trifluoromethyl, or may be further annelated.
10. An N-sulphonated compound according to claim 5 wherein the compound is a merocyanine dye of the general formula III:

in which R, L, A, Z, m, R2 and R3 have the meanings assigned above, q is O or 1, and Y and Z are CN or carbonyl containing groups, or Y and Z together are combined to form a ring which contains a carbonyl group.
11. An N-sulphonated compound according to claim 10 wherein Z is an hydantoin, thiohydantoin or rhodanine ring.
12. A method of'preparation of the dyes according to claim I wherein an N-sulphonated compound of general formula IV:

in which A, R, and L have the meanings assigned in the foregoing claims, and G is a lower alkyl group or a leaving group, or is a group containing a leaving group is used as an intermediate