Patent GB-684187-A (GB)
Title: Improvements in merocyanine dyestuffs
IPC: C09B23/10
Filed: 1950-09-01
Abstract: 2 - Hydroxythionaphthen - 3 - aldehyde anil is prepared by reacting together 2-hydroxythionaphthen and diphenylformamidine.  2 - Hydroxy - 3 - acetylthionaphthen is prepared by condensing 2-hydroxythionaphthen and diphenylacetamidine and hydrolysing the resulting anil.ALSO:Merocyanine dyes of the general formula <FORM:0684187/IV (c)/1> wherein n is 0 or 1, R1 is H or a hydrocarbon radical, R2 is H or methyl, R3 is a hydrocarbon radical, X is the residue of a 5- or 6-membered heterocyclic nitrogen ring or a polycyclic homologue thereof, and the benzene nucleus A may carry one or more substituents or a fused-on ring, are prepared by heating a 2-hydroxythionaphthen-3-aldehyde or an anil thereof or a 2-hydroxythionaphthen carrying as substituent in the 3-position a -CO-R group, where R is a hydrocarbon radical, with a quaternary salt of a heterocyclic nitrogen compound carrying a methyl or ethyl group in the a - or g -position to the quaternary nitrogen atom or with a heterocyclic nitrogen compound carrying a methylene group in the a -position to a tertiary nitrogen atom, preferably in an organic liquid medium in the presence of a basic substance. 3-(N-Ethylbenzthiazolylidene - ethylidene) - 2 - ketodihydrothionaphthen is prepared by refluxing together 2 - hydroxythionaphthen - 3 - aldehyde (or its anil), 2 - methylbenzthiazole ethiodide, piperidine, and methanol.  3-(1 : 3 : 3-Trimethylindolylidene - ethylidene) - 2 - keto - 6 - ethoxydihydrothionaphthen, 3 - (N - methylbenzselenazolylideneethylidene) - 2 - ketodihydrothionaphthen, 3 - (N - methyldihydroquinolylidene - (2) - ethylidene) - 2 - keto - 4 : 5 - benzdihydrothionaphthen, 3 - (N - methyldihydropyridylidene - ethylidene) - 2 - ketodihydrothionaphthen, 3 - (N - ethyldihydrobenzthiazolylidene - b  - methylethylidene) - 2 - ketodihydrothionaphthen, 3 - (N - methyldihydrobenzthiazolylidene - a - methylethylidene) - 2 - keto - dihydrothionaphthen, 3 - (N - methyldihydrobenzthiazolylidene - a  : b  - dimethylethylidene) - 2 - ketodihydrothionaphthen, 3 - [N - methyldihydroquinolylidene - (2) - ethylidene] - 2 - ketodihydrothionaphthen, 3 - [N - ethyldihydroquinolylidene - (2) - ethylidene] - 2 - ketodihydrothionaphthen, 3 - [N - methyldihydroquinolylidene - (4) - ethylidene]-2 - ketodihydrothionaphthen, 3 - (1 : 3 : 3 - trimethyldihydroindolylidene - ethylidene) - 2 - ketodihydrothionaphthen, 3 - [N - methyldihydroquinolylidene - (2) - ethylidene] - 2 - keto - 6 - ethoxy - dihydrothionaphthen, 3 - [N - methyldihydroquinolylidene - (4) - ethylidene] - 2 - keto - 6 - ethoxydihydrothionaphthen, 3 - [N - methyldihydroquinolylidene - (4) - ethylidene] - 2 - keto - 4 : 5 - benzdihydrothionaphthen, 3 - [N - methyldihydroquinolylidene - (2) - ethylidene] - 2 - keto - 4 - methyl - 6 - chlorodihydrothionaphthen, 3 - [N - methyldihydroquinolylidene - (4) - ethylidene] - 2 - keto - 4 - methyl - 6 - chlorodihydrothionaphthen, 3 - [N - methyldihydropyridylidene - (4) - ethylidene] - 2 - ketodihydrothionaphthen, 3 - [N - ethyldihydrobenzthiazolylidene - ethylidene] - 2 - keto - 6 - ethoxydihydrothionaphthen, 3 - [N - ethyldihydrobenzthiazolylidene - ethylidene) - 2 - keto - 4 : 5 - benzdihydrothionaphthen, 3 - (N - ethyldihydrobenzthiazolylidene - ethylidene) - 2 - keto - 4 - methyl - 6 - chlorodihydrothionaphthen, 3 - (N - ethyl - 5 : 6 - dimethyldihydrobenzthiazolylidene - ethylidene) - 2 - ketodihydrothionaphthen, 3 - (N - ethyl - 6 : 7 - tetramethylene - dihydrobenzthiazolylidene - ethylidene) - 2 - ketodihydrothionaphthen, 3 - (N - ethyl - 4 : 5 - diphenyldihydrothiazolylidene - ethylidene) - 2 - ketodihydrothionaphthen, 3 - (N - ethyl - 6 - chlorodihydrobenzthiazolylidene - ethylidene) - 2 - ketodihydrothionaphthen, 3 - (N - ethyl - 4 : 5 : benzdihydrobenzthiazolylidene - ethylidene) - 2 - ketodihydrothionaphthen, 3 - (N - ethyldihydroquinolylidene - (4) - ethylidene) - 2 - ketodihydrothionaphthen, 3 - (N - ethyldihydrobenzselenazolylidene - ethylidene) - 2 - ketodihydrothionaphthen, 3 - [N - ethyldihydroquinolylidene - (4) - ethylidene] - 2 - keto - 6 - ethoxythionaphthen, and the dye from 11 - phenyl - 2 - methylindolo - (31 : 21 - 3 : 4) - isoquinoline methiodide and 2-hydroxythionaphthen-3-aldehyde are similarly prepared.