Patent GB-431187-A (GB)
Title: Improvements in or relating to the production of compounds containing a polymethine chain
IPC: C09B23/01
Filed: 1933-12-23
Abstract: Dyes containing a polymethine chain are prepared by reacting a body containing the grouping <FORM:0431187/IV/1> (wherein R1, R2, R3 may be hydrogen or the hydrocarbon groupings of a cyclopentadiene homologue or R1 and R2 may be part of an arylene residue as in indene) with a quaternary salt of a heterocyclic nitrogen compound containing as a reactive group a thioether or selenoether grouping. An alternative procedure comprises reacting the above 5-membered ring compound, heterocyclic nitrogen base and an alkyl salt together so as to form the quaternary salt simultaneously with the main reaction. Starting materials comprise cyclopentadiene and its homologues and indenes; on the other hand quaternary salts derived from heterocyclic nitrogen bases having reactive a - or g - alkyl-, aryl-, aralkyl thioether or selenoether or thione or selenone groupings and alkyl salts (the selenoether derivatives are obtained by heating an a - or g -chloro substituted heterocyclic nitrogen base with alcoholic selenourea followed by alkylation of the resulting selenomercaptan); reference is made to quaternary salts of alkyl-quinoline-2-thiones, alkylmercapto derivatives of quinolines, thiazoles, oxazoles, pyridines, diazoles, quinazolines, pyrimidines and phthalazines. Many of the dyes are useful for modifying the sensitivity of photographic emulsions (cf. Specification 431,142, [Group XX]), and some appear to be suitable for dyeing textiles.  They are all regarded as carbocyanines in which the trimethine chain is itself part of a five-membered carbocyclic ring system.  In examples: (1) 1 - methylmercaptobenzthiazole is heated with methyl- or ethyl-p-toluenesulphonate, cyclopentadiene and pyridine added with further heating, and the products precipitated as the bromide and iodide respectively by adding potassium bromide or iodide to give 2 . 2<1> - dimethyl ( - or - diethyl -) - 7 . 7<1> - dimethenylthiocarbocyanine bromide or iodide.  By similar or analogous processes the following dyes are also made:--1 . 1<1> - dimethyl - and 1 . 1<1> - diethyl - 9 - 9<1> - dimethenyl - 2 . 2<1> - carbocyanine bromide from 1 - methyl - and 1 - ethyl - quinoline - 2 - thiones respectively, 2 . 2<1> - dimethyl (and - diethyl -) - 4 . 5 . 4<1> . 5<1> - tetraoxydimethylene - 7 . 7<1> - dimethenylthiocarbocyanine - p - toluene sulphonate from 1 - methylmercapto - 4 . 5 - dioxymethylenebenzthiazole, 2 . 2<1> - dimethyl - (and - diethyl -) 4 . 5 : 4<1> . 5<1> - tetramethoxy - 7 . 7<1> - dimethenyl-thiocarbocyanine - p - toluenesulphonate from 1 - methylmercapto - 4 . 5 - dimethoxybenzthiazole, thiocarbocyanines from dimethylmercapto - b  . b <1> - thiodiazole (cf. Example 1 of Specification 425,609), cyclopentadiene and ethyl - and methyl - p - toluenesulphonates, 2 . 2<1> - dimethyl - 3 . 4 . 3<1> . 4<1> - dibenzo - 7 . 7<1> - dimethynylthiocarbocyanine - p - toluenesulphonate from 2 - methylmercapto - b  - naphthothiazole, 2 . 2<1> - dimethyl - 7 . 7<1> - dimethenyloxacarbocyanine bromide from 1 - methylmercaptobenzoxazole; (2) 1 . 1<1> - dimethyl - 9 . 9<1> - o - phenylene - 2 . 2<1> - carbocyanine - p - toluenesulphonate is prepared by heating methylquinoline - 2 - thione with ethyl - p - toluenesulphonate and indene in presence of pyridine; by similar or analogous processes the following dyes are also obtained:--1 . 1<1> - diethyl - 9 . 9<1> - o - phenylene - 2 . 2<1> - carbocyanine bromide from 1 - ethylquinoline - 2 - thione, 2 . 2<1> - dimethyl - 7 . 7<1> - o - phenylenethiocarbocyanine iodide from 1 - methylmercaptobenzthiazole and 2 . 2<1> - diethyl - 7 . 7<1> - o - phenylenethiocarbocyanine p - toluenesulphonate and iodide from this base, 2 . 4 . 6 . 2<1> . 4<1> . 6<1> - hexamethyl - 7 . 7<1> - o - phenyleneoxacarbocyanine iodide from 1 - methylmercapto - 4 . 5 - dimethylbenzoxazole, dimethyl - o - phenylene - phthalazocarbocyanine iodide from methyl-mercaptophthalazine (prepared by heating phthazonic acid to give phthazone, treating this with phosphorus pentachloride and then with potassium hydrogen sulphide and finally methylating), 2 . 2<1> - dimethyl - 7 . 7<1> - o - phenyleneoxacarbocyanine iodide from 1-methylmercaptobenzoxazole, 2 . 2<1> - dimethyl - (and - diethyl -) - 4 . 5 . 4<1> . 5<1> - tetroxydimethylene - 7 . 7<1> - o - phenylenethiocarbocyanine - p - toluenesulphonate from 1 - methylmercapto - 4 . 5 - dioxymethylenebenzthiazole, 2 . 2<1> - dimethyl - 4 . 5 . 4<1> . 5<1> - tetramethoxy - 7 . 7<1> - o - phenylene - thiocarbocynic bromide from 1 - methylmercapto - 4 . 5 - dimethoxybenzthiazole, thiocarbocyanine dyes from dimethylmercapto - b .b <1> (and - a  . b <1> -) - thiodiazoles, indene and methyl- and ethyl-p-toluenesulphonates, 1 . 1<1> - diethyl - 9 . 9<1> - o - phenylene - 4 . 4<1> - quinazocarbocyanine iodide and the corresponding dimethyl - p - toluenesulphonate, 2 . 2<1> - dimethyl - 3 . 4 . 3<1> . 4<1> - dibenzo - 7 . 7<1> - o - phenylene-thiocarbocyanine bromide, 3 . 3<1> - dimethyl - 2 . 2<1> - dimethylmercapto - o - phenylene - 4 . 4<1> - pyrimidocarbocyanine - p - toluenesulphonate and the corresponding diethyl-bromide compound, 1 . 1<1>-dimethyl - 7 . 7<1> - o - phenylene - 2 . 2<1> - pyridocarbocyanine iodide from 2-methylmercaptopyridine and 3 . 3<1> - dimethyl - 2 . 2<1> . 6 . 6<1> - tetramethylmercapto - o - phenylene - 4 . 4<1> - pyrimidocarbocyanine bromide from 2 . 4 . 6 . trimethylmercaptopyrimidine.