Patent GB-450958-A (GB)
Title: Improvements in photographic emulsions
IPC: G03C1/22
Filed: 1934-10-15
Abstract: Dyes having the grouping <FORM:0450958/IV/1> wherein A stands for oxygen or sulphur, C<4>--N<1>--C<1>--C<2>-- form part of a five or six-membered heterocyclic ring, N<2> forms part of a second heterocyclic ring, the linkage between the nuclei being through the carbon atom in the a - of g -position to N<2>, and n stands for 1, 2 or 3, are prepared by condensing a 5- or 6-membered heterocyclic ring compound comprising the grouping <FORM:0450958/IV/2> with a heterocyclic nitrogen compound containing in a - or g -position to the nitrogen atom a halogen, a thioether group or an arylido mono- or di-vinyl group.  Such condensation is often advantageously effected in presence of a strong organic base such as triethylamine as condensing agent.  In the cases where N<2>--forms part of a quinoline nucleus linked to the rest of the molecule through the g -position to N<2> condensation may also be effected by using as starting material a quinoline compound which is unsubstituted in the g -position.  In the cases where the foregoing products contain a thiohydantoin or rhodanine residue they may be subjected to a further alkylation in presence of alkali to yield further products.  These substances are of use in sensitizing photographic silver halide emulsions; for this purpose they may be added to the uncast emulsion in the form of a solution, for instance an alcoholic solution, in quantities of about 1 part per 250,000 parts wet emulsion, or the coated emulsion may be bathed in a solution of the dye.  The dyes may also be selected where different emulsions having differing sensitivities to different colours for use in colour photography are required; thus multi-layer or multi-particle layer films for colour photography (see for example Specifications 245,198, [Class 98 (ii)], and 376,838, and 444,198, [both in Group XX], may be sensitized by incorporating one or more dyes in one or more layers or batches of particles.  As an example of a three-colour process different emulsions may be sensitized, (a) high for green and yellow by means of 5 - (2 - ethyl - 1 - benzoxazylidene - ethylidene 3 - phenyl - 2.4 - thiazoledione, (b) to yellow and red by means of 5-(1-ethyl-2-quinolylideneethylidene) - 3 - phenyl - 2.4 - thiazoledione, or 3 - ethyl - 5 - (2 - ethyl - 1 - benzoxazylidenebutenylidene)-rhodanine, and (c) to blue by means of 3-ethyl-5-(2-ethyl-1-benzothiazolyidene)-rhodanine. Dyes may also be selected which sensitive emulsions in sharply defined regions of the spectrum, and thus permit of subsequent operations on these emulsions being performed in various safe-lights.  The manufacture and sensitizing properties of the products are exemplified in considerable detail, in almost all cases the sensitizing spectrograms of the products of the examples being furnished.  The examples are comprised within the following type preparations: (1) (a) 5 - (1 - ethyl - 2 - quinolylidene) - 3 - phenylrhodanine by condensing 2-phenylthio- or 2-iodoquinoline ethiodide with 3-phenylrhodanine in alcohol and in presence of triethylamine; (b) 5-(1-ethyl-4-quinolylidene)-rhodanine by condensing quinoline ethiodide with 3-ethylrhodanine in alcoholic potash; (c) 5-(1 -ethyl-2-quinolylidene)-2-methylmercapto-4(5)-thiazolone by treating 5-(1-ethyl-2-quinolylidene)-rhodanine in alcoholic potash with methyl-p-toluenesulphonate.  In analogous manner are prepared similar compounds wherein a double linkage unites N-ethyl-benzthiazole (1) with 2 - diphenylamino - 4(5) - thiazolone, 1.3-diphenyl-2-thiohydantoin, 3-ethyl-2-thio-2.4-oxazoledione, 3-ethylrhodanine and 3-phenylrhodanine, N-ethyl-benzoxazole (1) with 3-ethylrhodanine, N-ethylquinoline (2) with 3-ethyl2-thio-2.4-oxazoledione, 3-ethyl- 1 -phenyl-2-thiohydantoin, 2.4.6-triketohexahydropyrimidine, 2-thio-2.4.6-triketohexahydropyrimidine, 3-ethylrhodanine and rhodanine; N-ethyl-quinoline-(4) with 3-phenylrhodanine, 2-ethylmercapto and -methylmercapto-4(5)-thiazolone, and rhodanine; N-ethylpyridine (2) with 3-phenylrhodanine, and 3-ethylrhodanine; N-ethyl-b -naphthoquinoline (2) with rhodanine, 3-ethylrhodanine and 3-phenylrhodanine.  (2) (a) 5 - (2 - ethyl - 1 - benzoxazylidene - ethylidene)-hydantoin is prepared by condensing hydantoin with 1-b -acetanilidovinylbenzoxazole ethiodide in acetic anhydride and in presence of sodium acetate; (b) 4 - (2 - ethyl - 1 - benzoxazylideneethylidene) - 2 - methylmercapto - 1 - phenyl - 5(4)-imidazolone is prepared by treating 5-(2-ethyl-1-benzoxazylidene-ethylidene) - 3 - phenyl - 2 - thiohydantoin in alcoholic potash with methyl-p-toluenesulphonate. In an analogous manner similar compounds are prepared wherein an ethylidene linkage unites N-ethylbenzoxazole (1) with 3-aminorhodanine, 3-phenylaminorhodanine, 3-carbethoxymethylrhodanine, 3-p-dimethylaminophenyl - rhodanine, 3 - ethylrhodanine, 3-isopropylrhodanine, 3-allylrhodanine, 3-b -oxyethylrhodanine, 3-methylrhodanine, 3 - n - propylrhodanine, 3 - phenylrhodanine, 3-phenyl-2-thiohydantoin, 3-ethyl-2 - thiohydantoin, 3 - methyl - 2 - thiohydantoin, 1-phenyl-2-thiohydantoin, 1.3-diphenyl-2-thio-hydantoin, 2-thiohydantoin, 3-ethyl-1-phenyl-2-thiohydantoin, 1 - acetyl - 2 - thiohydantoin, 4-thiohydantoin, 2 - methylmercapto - 1 - methyl-5(4) -imidazolone, 3-ethyl-2-thio-2.4-oxazoledione, 3-p-tolyl-2.4-thiazoledione, 3-phenyl2.4-thiazoledione, 3-phenyl-2-phenylimino-4-thiazolidone, 2-methylphenylamino-4(5) -thiazolone, 2 - ethylphenylamino - 4(5) - thiazolone, 2 - diphenylamino - 4(5) - thiazolone, 2 - phenylamino-4(5)-thiazolone, 2-methylmercapto-4(5)-thiazolone, 2 - ethylmercapto - 4(5) - thiazolone, 2.4.6 - triketohexahydropyrimidine and 2-thio-2.4.6 - triketohexahydropyrimidine; N-methylbenzoxazylidene (1) with 3-ethylrhodanine; N - allylbenzoxazylidene (1) with 3 - ethylrhodanine; N-methylthiazoline with 2-thio-2.4-oxazoledione, 3-ethyl-2-thio-2.4-oxazoledione, 3-ethyl-1-phenyl-2-thiohydantoin, 3-ethylrhodanine, and 3-phenylrhodanine; N-ethylbenzthiazole-(1) with 3-phenyl-4-thiorhodanine, 3 - phenylrhodanine, 3 - ethylrhodanine, 3 - n - propylrhodanine, 3 - isopropylrhodanine, 2 - methylphenylamino - 4(5)-thiazolone, 2 - ethylphenylamino - 4(5) - thiazolone, 2 - phenylamino - 4(5) - thiazolone, 2-diphenylamino - 4(5) - thiazolone, 2 - ethylmercapto - 4(5) - thiazolone, 2 - methylmercapto-4(5) - thiazolone, 3 - phenyl - 2 - phenylimino - 4 - thiazolidone, 2.4.6 - triketohexahydropyrimidine, 2-thio-2.4.6-triketohexahydropyrimidine, 3-ethyl-2-thiohydantoin, 2-thiohydantoin, 1.3-diphenyl-2-thiohydantoin, 3-ethyl-1-phenyl-2-thiohydantoin, 4 - thiohydantoin, 3 - ethyl - 2 - thio - 2.4 - oxazoledione, 2 - thio - 2.4 - oxazoledione and 3-phenyl-2.4-thiazoledione; N-ethyl-b -naphthathiazole-(2) with 2-diphenylamino - 4(5) - thiazolone, 3 - phenylrhodanine, rhodanine and 3-ethylrhodanine; N-ethylbenzselenazole-(1) with 2-diphenylamino-4(5)-thiazolone; N-ethylquinoline-(2) with 3-aminorhodanine, 3 - methylrhodanine, 3 - ethylrhodanine, 3-carbethoxymethylrhodanine, 3-p-dimethylaminophenylrhodanine, 3 - phenylaminorhodanine, 3 - phenylrhodanine, 2-diphenylamino - 4(5) - thiazolone, 2 - methylmercapto - 4(5) - thiazolone, 1.3 - diphenyl - 2 - thiohydantoin, 3-p-tolyl-2.4-thiazoledione, 3-phenyl - 2.4 - thiazoledione and 3 - phenyl - 2 - phenylimino-4-thiazolidone; N-methylquinoline-(2) with 3-ethylrhodanine; N-ethylquinoline-(4) with 3-ethylrhodanine, rhodanine and 3-phenylrhodanine; 3-ethylrhodanine with 1.6-dimethylquinoline-(2) and 1-ethyl-6-methylquinoline-(2); 3-ethylrhodanine with 1-methyl-6-ethoxyquinoline-(2) and 1-ethyl-6-ethoxyquinoline-(2); N-ethyl-b -naphthoquinoline-(2) with 3-ethylrhodanine; (3) 5-(1-ethyl-2-b -naphthathiazylidine - butenylidene - 1.3 - diphenyl-2-thiohydantoin is prepared by condensing 2 - o  - acetanilido - butadienyl(1.3)-b -naphthothiazole ethiodide with 1.3-diphenyl-2-thiohydantoin in alcohol and in presence of triethylamine.  In an analogous manner similar compounds are prepared wherein a butadienyl chain unites N-ethylbenzthiazole-(1) with 3-ethyl - 2 - thio - 2.4 - oxazoledione, 3 - ethylrhodanine, 3-phenylrhodanine, rhodanine, 2-diphenylamino - 4(5) - thiazolone and 1.3-diphenyl - 2 - thiohydantoin; N - ethylbenzoxazole-(1) with 2-diphenylamino-4(5)-thiazolone and 3-ethylrhodanine; N-ethylbenzselenazole-(2) with 1.3-diphenyl-2-thiohydantoin and 2-diphenylamino -4(5) - thiazolone.  Specification 355,693 also is referred to.  2 - b  - anilidovinylthiazoline methiodide is prepared by the action of diphenylformamidine on 2-methylthiazoline methiodide in glacial acetic acid.  Butodienyl-azole derivatives.  The m -o -acetanilidobutadienyl(1.3) - derivatives of benzoxazole ethiodide, benzthiazole ethiodide, benzselenazole ethiodide, and b -naphthothiazole ethiodide are prepared by treating the corresponding m -methyl derivatives with b -anilinoacrolein-anil hydrochloride in acetic anhydride.  Rhodanines.  3-b -oxyethylrhodanine, 3-n-propylrhodanine and 3-isopropylrhodanine are prepared analogously to 3-ethylrhodanine (cf. J. prak. Chem 81, 451), 3 - phenyl - 4 - thiorhodanine is prepared by treating 3-phenylrhodanine in toluene with phosphorus pentasulphide.  3-Ethyl-1-phenyl-2-thiohydantoin is prepared by reacting together a mixture of phenylglycine ethyl ester and ethylisothiocyanate.  Benzthiazole and benzoxazole thioethers. 1-Methylmercaptobenzthiazole is prepared by alkylating 1-mercaptobenzthiazole; the corresponding 1-phenyl, 1-n-butyl and 1-b -naphthyl derivatives are similarly made, and likewise the corresponding oxazole derivatives.  Reference has been directed by the Comptroller to Specifications 426,718, 428,222, and 428,359.