Patent GB-886271-A (GB)
Title: Improvements in or relating to sensitized photographic emulsions and to new sensitizing dyes
Inventor: NYS JEAN MARIE
IPC: C07D293/12
Filed: 1957-06-20
Abstract: Quaternary salts of heterocyclic nitrogen compounds having a group -A-CO-O-B-SO3M (where A is a -CH2- or p-CH2-C6H4-group, B is a methylene, ethylene, propylene or butylene group and M is an alkali metal atom or ammonium group) on the nitrogen atom are prepared by reacting the corresponding base with a compound of the formula X-A-CO-O-B-SO3M wherein X is a halogen atom.  Examples are giving using as base 2-methyl-benzselenazole, 2-methyl-benzthiazol and its 6-methyl, 6-methoxy, 5-methyl or 5,6-dimethyl derivatives, 2-methylbenzoxazole and its 6-methoxy or 5-phenyl derivatives, 2-methyl-thiazoline, 2,4-dimethylthiazole and 1-ethyl-2-methyl-5,6-dichlorobenzimidazole.  Alternatively, the quaternary salts can be prepared by treating the base with a compound X-A-COOH to give a quaternary salt having a -A-COOH group on the nitrogen atom and reacting this with n-propane sultone or n-butane sultone.  An example is given of reacting 2-methyl-3-p-carboxybenzyl-benzthiazolium bromide with butane sultone in the presence of sodium methoxide.  Compounds of the general formula X-A-CO-O-B-SO3M(I) wherein B is a propylene or butylene radical and the other symbols are as defined above are prepared by heating a compound of the formula X-A-COOM with propane sultone or butane sultone. Examples are given of heating sodium bromo-acetate with propane sultone or butane sultone.  Compounds of formula I wherein B is a methylene group are prepared by heating an anhydride (X-A-CO)2O with a compound of the formula HO-CH2-SO2-OM.  An example is given of heating bromo-acet-anhydride with sodium hydroxy-methane sulphonate.ALSO:The invention relates to monomethine, trimethine and rhodacyanine dyes in which at least one of the heterocyclic nitrogen atoms carries the group -A-CO-O-B-SO3- wherein A is a methylene or p-CH2-C6H4-group and B is methylene, ethylene, propylene or butylene radical, the group forming an internal salt with the nitrogen atom. Examples are given of the preparation of a monomethine dye from 2-methyl-3(o -sodium sulpho-carbobutoxymethyl)- benzthiazolium bromide and 2-methylmercapto-3-methyl-b -naphthothiazolium methosulphate, of the preparation of symmetrical trimethine dyes from benzthiazolium or benzoxazolium salts having a 3-(o -sodium sulpho-carbobutoxymethyl) group and ethyl ortho formate, of the preparation of unsymmetrical meso substituted carbocyanine dyes from 2-methyl-3-(sodium sulpho-carbomethoxymethyl) benzthiazolium bromide and 2-(b -methyl-b -methylmercaptovinyl) - 3 - ethyl - benzthiazolium methosulphate or from 2-methyl-3-(o -sodium sulpho-carbopropoxymethyl) benzselenazolium bromide and 2-(b -methyl-b -methylmercaptovinyl)-3-ethyl-benzselenazolium methosulphate, and of the preparation of unsymmetrical trimethine dyes by condensing benzthiazolium, benzoxazolium, benzselenazolium or thiazolium salts having a -A-CO-O-B-SO3Na group on the nitrogen atom with b -acetanilino-vinyl derivatives of selenazolinium, thiazolinium, benzthiazolium, benzoxazolium or b -naphthothiazolium salts or by condensing 1-ethyl-2-methyl-3-(sodium sulpho-carbomethoxymethyl)-5; 6-dichloro-benzimidazolium bromide with 2-(phenylimino - ethylidene) - 3 - ethyl - benzoxazoline.  A rhodacyanine dye is prepared by condensing 2 - methyl - 3 - [p - (o - sulpho - carbobutoxy) benzyl] benzthiazolium bromide with the methyl-p-toluene sulphonate of 3-ethyl-5-[a -benzyl-b -(3-ethyl 2- 3-dihydro-2-benzthiazolylidene) ethylidene]-rhodanine.