Patent GB-637387-A (GB)
Title: Trinuclear cyanine dyes and photographic silver halide emulsions sensitized with the dyes
IPC: C09B23/01
Filed: 1947-05-05
Abstract: 1 - Ethyl - 2 - amino - 5 - methyl - 1 : 3 : 4-triazole is prepared by adding sodium ethylate to an ethanol solution of 2-amino-5-methyl-1 : 3 : 4-triazole and then adding ethyl iodide dropwise.  2 - Amino - 4 - ethyl - 5 - methyl - 1 : 3 : 4-thiadiazolium iodide is prepared by heating together at 105 DEG  to 110 DEG  C. for 4 hours in a sealed bomb 2 - amino - 5 - methyl - 1 : 3 : 4-thiadiazole and ethyl iodide.  2 - Amino - 3 - ethyl - 5 - methyl - 1 : 3 : 4-thiadiazolium iodide is obtained as a by-product. 2 - Amino - 4 - ethyl - 5 - methyl - 1 : 3 : 4-oxadiazolium iodide and 1 : 4-diethyl-2-amino-5-methyl-1 : 3 : 4-triazolium iodide are similarly obtained.  Specifications 461,688 and 489,335, [both in Group IV], are referred to.ALSO:Dyes of the general formula <FORM:0637387/IV (c)/1> wherein A is the residue of a heterocyclic nitrogen compound, R and R2 are alkyl or aralkyl groups, X is an acid radical, Y is O, S, or NR1 (R1 being hydrogen or an alkyl group), m is 0, 1 or 2, and p is 0 or 1 are prepared by condensing in the presence of an acid binding agent a compound of the general formula <FORM:0637387/IV (c)/2> with a compound of the general formula <FORM:0637387/IV (c)/3> wherein R2 is an anilido or hydrocarbonmercapto group.  The second reactant may be obtained by quaternizing 2-amino-5-methyl-1 : 3 : 4 - oxadiazole, 2 - amino - 5 - methyl-1 : 3 : 4 - thiadiazole, or 2 - amino - 5 - methyl-1 : 3 : 4-triazole. Numerous intermediates suitable for use as the first reactant are described.  Dyes are prepared by heating together in pyridine containing triethylamine 2 - amino - 4 - ethyl - 5 - methyl - 1 : 3 : 4-thiadiazolium iodide, and (1) 2-(b -acetanilidovinyl) - 3 - ethylbenzthiazolium iodide; (2) 2 - (b  - acetanilidovinyl) - 3 - ethylbenzoxazolium iodide; (3) 2 - methylmercapto - 1-ethyl - 6 - methylquinolinium iodide; (4) 2-(b  - acetanilidovinyl) - 3 - ethyl - 5 : 6 - methylenedioxybenzthiazolium iodide; (5) 2 - (b -anilidovinyl) - 3 - ethyl - 4 : 5 - diphenylthiazolium iodide; (6) 2 - methylmercapto-3 - ethylbenzselenazolium iodide; (7) 2-methylmercapto - 3 - ethyl - 5 : 6 - dimethoxybenzselenazolium - p - toluenesulphonate; (8) 2 - methylmercapto - 3 - methyl - 4 - p - tolyl-5 - phenylthiazolium iodide; (9) 2 - methylmercapto - 3 - ethylbenzthiazolium iodide; (10) 2 - (b  - anilidovinyl) - 3 - ethyl - 6 - methoxybenzselenazolium iodide; (11) 2 - (b  - acetanilidovinyl)-3-ethylbenzselenazolium iodide; (12) 2 - (b  - anilidovinyl) - 1 - ethyl - 3 : 3 : 5-trimethylindoleninium iodide; (13) 2 - (b -anilidovinyl) - 3 - methylthiazolinium iodide; (14) 2 - (b  - acetanilidovinyl) - 3 - ethyl - 5-methoxybenzthiazolium iodide; (15) 2 - (b -acetanilidovinyl) - 3 - ethyl - 4 : 5 - benzbenzoxazolium iodide; (16) 2 - (b  - acetanilidovinyl) - 3 - ethyl - 5 : 6 - dimethylbenzoxazolium iodide; (17) 2-(b -acetanilidovinyl)-3-ethyl-5-phenylbenzoxazolium iodide; (18) 2-(b -acetanilidovinyl) - 3 - ethyl - 5 - methoxybenzoxazolium iodide; (19) 2-(b -acetanilidovinyl)-3-ethyl-5-methylbenzthiazolium iodide, and (20) 2-(4)-acetanilidobutadienyl - 3 - ethylbenzthiazolium iodide; 2 - amino - 4 - ethyl - 5 - methyl-1 : 3 : 4 - oxadiazolium iodide and 2 - (b -acetanilidovinyl) - 3 - ethyl - 6 - methylbenzthiazolium iodide; and 1 : 4-diethyl-2-amino - 5 - methyl - 1 : 3 : 4 - triazolium iodide and 2 - (b  - acetanilidovinyl) - 3 - ethylbenzthiazolium iodide.  In the case of dyes (5), (10), (12), (13), (14), (15), and (17), the reaction mixture also contains acetic anhydride.  Dyes (2), (5), (10), (12), (13), (16), (17), and (18) are converted to the perchlorate, and dye (7) to the bromide. Specifications 461,688 and 489,335, [both in Group IV], are referred to.