Patent GB-681451-A (GB)
Title: Improvements in or relating to polymethine compounds and to photographic silver halide emulsions sensitised therewith
Inventor: KENDALL JOHN DAVID
IPC: C09B23/01
Filed: 1950-03-20
Abstract: Dyes of the general formula <FORM:0681451/IV (c)/1> wherein R1 and R2 are alkyl or aralkyl groups, D is the residue of a substituted or unsubstituted thiazole nucleus, X is 0 or 5, and Y is -CN or -COOR3 (R3 being alkyl or aralkyl), are prepared by condensing dyes of the general formula <FORM:0681451/IV (c)/2> wherein Z is an acid radicle, with compounds of the general formula <FORM:0681451/IV (c)/3> wherein R4 is an alkyl or aralkyl group, in the presence of a strong inorganic or secondary or tertiary organic base.  Ethyl 6-(31-methyl-21 : 31-dihydrobenzthiazolylidene - 21) - 5 - methoxy - 2 - cyano-2 : 4-hexadienoate is prepared by fusing together 2 - acetylmethylene - 3 - methyl - 2 : 3 - dihydrobenzthiazole and methyl p-toluenesulphonate, adding alcohol and ethyl ethoxymethylenecyanacetate, warming, adding triethylamine, and refluxing.  Ethyl 6-(31-ethyl-21 : 31 - dihydro - 41 : 51 - benzbenzthiazolylidene - 21) - 5 - ethoxy - 2 - cyano - 2 : 4 - hexadienoate, ethyl 6 - (31 - ethyl - 21 : 31 - dihydrobenzthiazolylidene - 21) - 5 - ethoxy - 2 - cyano - 2 : 4 - hexadienoate, ethyl 6 - (31 - ethyl - 21 : 31 - dihydrobenzthiazolylidene - 21) - 5 - methoxy - 2 - cyano - 2 : 4 - hexadienoate, 5 - (31 - methyl - 21 : 31 - dihydrobenzthiazolylidene - 21) - 4 - methoxy - 1 : 1 - dicyano - 1 : 3 - pentadiene, 5 - (31 - methyl - 21 : 31 - dihydro - 41 : 51 - benzbenzthiazolylidene - 21) - 4 - ethoxy - 1 : 1 - dicyano - 1 : 3 - pentadiene, 5 - (31 - methyl - 21 : 31 - dihydrobenzthiazolylidene - 21) - 4 - ethoxy - 1 : 1 - dicyano - 1 : 3 - pentadiene, 5 - (31 - ethyl - 21 : 31 - dihydrobenzthiazolylidene - 21) - 4 - ethoxy - 1 : 1 - dicyano - 1 : 3 - pentadiene 5 - (31 - methyl - 21 : 31 - dihydrobenzthiazolylidene - 21) - 4 - methoxy - 1 : 1 - dicyano - 1 : 3 - pentadiene, 5 - (31 - methyl - 21 : 31 - dihydrobenzthiazolylidene - 21) - 4 - ethylthio - 1 : 1 - dicyano - 1 : 3 - pentadiene, ethyl 6 - (31 - methyl - 21 : 31 - dihydrobenzthiazolylidene - 21) - 5 - ethylthio - 2 - cyano - 2 : 4 - hexadienoate, ethyl 6 - (31 - methyl - 21 : 31 - dihydro - 51 : 61 - benzbenzthiazolylidene - 21) - 5 - ethylthio - 2 - cyano - 2 : 4 - hexadienoate, ethyl 6 - (31 - ethyl - 21 : 31 - dihydro - 41 : 51 - benzbenzthiazolylidene - 21) - 5 - ethylthio - 2 - cyano - 2 : 4 - hexadienoate, ethyl 6 - (31 - methyl - 21 : 31 - dihydro - 51 : 61 - dimethoxybenzthiazolylidene - 21) - 5 - ethylthio - 2 - cyano - 2 : 4 - hexadienoate, ethyl 6 - (31 - ethyl - 21 : 31 - dihydrobenzthiazolylidene - 21) - 5 - ethylthio - 2 - cyano - 2 : 4 - hexadienoate, 5 - (31 - ethyl - 21 : 31 - dihydro - 51 : 61 - benzbenzthiazolylidene - 21) - 4 - ethylthio - 1 : 1 - dicyano - 1 : 3 - pentadiene, 5 - (31 - ethyl - 21 : 31 - dihydro - 41 : 51 - benzbenzthiazolylidene - 21) - 4 - ethylthio - 1 : 1 - dicyano - 1 : 3 - pentadiene, 5 - (31 - methyl - 51 : 61 - dimethoxy - 21 : 31 - dihydrobenzthiazolylidene - 21) - 4 - ethylthio - 1 : 1 - dicyano - 1 : 3 - pentadiene, 5 - (31 - ethyl - 21 : 31 - dihydrobenzthiazolylidene - 21) - 4 - ethylthio - 1 : 1 - dicyano - 1 : 3 - pentadiene, 5 - (31 - ethyl - 51 : 61 - methylene-dioxy - 21 : 31 - dihydrobenzthiazolylidene - 21) - 4 - ethoxy - 1 : 1 - dicyano - 1 : 3 - pentadiene, 5 - (31 - ethyl - 41 - chloro - 21 : 31 - dihydrobenzthiazolylidene - 21) - 4 - ethoxy - 1 : 1 - dicyano - 1 : 3 - pentadiene, 5 - (31 - ethyl - 21 : 31 - dihydro - 41 : 51 - benzbenzthiazolylidene - 21) - 4 - methoxy - 1 : 1 - dicyano - 1 : 3 - pentadiene, ethyl 6-(31-ethyl-21 : 31-dihydro-51 : 61-methylenedioxybenzthiazolylidene - 21) - 5 p  - ethoxy - 2 - cyano - 2 : 4 - hexadienoate, ethyl 6 - (31 - ethyl - 51 - methyl - 21 : 31 - dihydrobenzthiazolylidene - 21) - 5 - ethoxy - 2 - cyano - 2 : 4 - hexadienoate, ethyl 6 - (31 - ethyl - 21 : 31 - dihydro - 41 : 51 - benzbenzthiazolylidene - 21) - 5 - methoxy - 2 - cyano - 2 : 4 - hexadienoate, methyl 6 - (31 - methyl - 21 : 31\h - dihydrobenzthiazolylidene - 21) - 5 - ethoxy - 2 - cyano - 2 : 4 - hexadienoate, and methyl 6 - (31 - methyl - 21 : 31 - dihydrobenzthiazolylidene - 21) - 5 - ethylthio - 2 - cyano - 2 : 4 - hexadienoate are similarly prepared.  According to the Provisional Specification, the dyes may have the formula <FORM:0681451/IV (c)/4> wherein R1, R2, X, and Y are as before, D may be the residue of a substituted or unsubstituted thiazole, oxazole, or selenazole nucleus, and n and x are each 0 o 1.