Patent GB-629123-A (GB)
Title: Improvements in the manufacture of intermediates for the production of dyes, in the manufacture of polymethin dyes and in photographic silver salt emulsions containing such dyes
IPC: C09B23/12
Filed: 1946-02-22
Abstract: Polymethine dyes are prepared by condensing a heterocyclic ternary nitrogen base having a dianiloisopropylidene group in the a - or g -position to the ternary nitrogen atom with a 5- or 6-membered heterocyclic compound having an intracyclic reactive methylene group adjacent to a carbonyl or thiocarbonyl group by heating together in presence of a condensing agent, the time and temperature of heating being sufficient to cause one molecular proportion of the base to combine with one molecular proportion but insufficient to combine with two molecular proportions of the reactive methylene compound to give a dye of the general formula <FORM:0629123/IV (c)/1> wherein P1(R2) represents the residue of a heterocyclic N compound connected in the a - or g -position to the N atom to which the group R2 is attached, R2 represents alkyl, aralkyl, or aryl, Q1 represents the residue of a 5- or 6-membered heterocyclic compound having an intracyclic reactive methylene group adjacent to a carbonyl or thiocarbonyl group, and Ar1 represents a phenyl or substituted phenyl group.  These dyes may be condensed with a further 5- or 6-membered heterocyclic compound having an intracyclic reactive methylene group adjacent to a carbonyl or thiocarbonyl group or with a quaternary salt of a heterocyclic nitrogen compound having a methyl group in the a - or g -position to the quaternary N atom to give a tri-nuclear polymethine dye.  5 - (3 - Ethylrhodanine)] [2 - (3 - ethylbenzthiazole)] - b  - anilomethyldimethinemerocyanine is prepared by heating together 3-ethyl-2-dianiloisopropylidenebenzthiazoline, 3 - ethylrhodanine, and pyridine.  Similar dyes may be prepared in which one nucleus is 2-(3-ethylbenzthiazole) or 2-(3-ethylbenzselenazole) and the other 2-(4-keto-2-thio-3-ethyltetrahydro-oxazole); in which one is 2-(5-chloro-3-ethylbenzthiazole) and the other 5-(1-phenyl-3-ethyl - 2 - thiohydantoin) or 5 - (2 - diphenylamino - 4 - keto - D 2 - thiazoline); in which one is 2-(3-ethylbenzselenazole) and the other 5 - (3 - ethylrhodanine) or 5 - (1 - phenyl - 3-ethyl - 2 - thiohydantoin); or in which one is 2 - (4 - methyl - 3 - ethylthiazole) and the other 5 - (3 - ethylrhodanine, 5 - (4 - keto - 2 - thio-3 - ethyltetrahydro - oxazole) or 5 - (1 - phenyl-3-ethyl-2-thiohydantoin).  [5 - (4 - Keto - 2 - thio - 3 - ethyltetrahydro-oxazole)] [2 - (3 - ethylbenzthiazole)] [b  - methin-51 - (31 - ethylrhodanine)] - dimethinemerocyanine is prepared by heating together either [5-(3-ethylrhocanine)] [2 - (3 - ethylbenzthiazole)]-b  - anilomethyldimethinemerocyanine, 4 - keto-2 - thio - 3 - ethyltetrahydro - oxazole, anhydrous sodium acetate, and acetic anhydride, or [5 - (4 - keto - 2 - thio - 3 - ethyltetrahydro-oxazole)] [2 - (3 - ethylbenzthiazole)] - a -anilomethyldimethinemerocyanine, 3 - ethylrhodanine, sodium acetate, and acetic anhydride.  Similar dyes can be obtained in which one nucleus is 2-(3-ethylbenzthiazole, the second 5-(3-ethylrhodanine), and the third either 5-(3 - ethylrhodanine) or 2 - (1 - ethylquinoline); in which one is 2-(4-methyl-3-ethylthiazole), the second 5-(3-ethylrhodanine), and the third 5 - (4 - keto - 2 - thio - 3 - ethyltetrahydro-oxazole); in which one is 2-(3-ethylbenzselenazole; the second 5-(3-ethylrhodanine), and the third either 5-(4-keto-2-thio-3-ethyl-tetrahydro - oxazole), 2 - (3 - ethylbenzthiazole), 2 - (3 - ethylbenzselenazole), or 2 - (3 - ethyl-6 : 7 - benzbenzthiazole); or in which one is 2-(4-methyl-3-ethylthiazole) and either the second 5-(3-ethylrhodanine) and the third 2-(3 - ethyl - 6 : 7 - benzbenzthiazole) or 2 - (3-ethylbenzthiazole or the second 5-(1-phenyl-3-ethyl-2-thiohydantoin) and the third 2-(3-ethylbenzthiazole).  Specifications 629,106 and 629,122 are referred to.