Patent GB-1209813-A (GB)
Title: Improved photographic silver halide material
Inventor: WILLEMS JOZEF FRANS
IPC: C07D249/12
Filed: 1968-02-22
Abstract: 1,209,813. Derivatives of aeterocyclic thioethers. GEVAERT-AGFA N.V. 12 Feb., 1969 [22 Feb., 1968], No. 8652/68. Heading C2C. [Also in Division G2] 2 - Methylthiomethyl - 5(6) - sulphobenzimidazole is prepared by refluxing 3,4-diaminobenzenesulphofluoride and (methylthio) acetic acid in 6N hydrochloric acid. 2-(2-Methylthioethyl)- 5(6)-sulphobenzimidazole, 2-(3-methylthiopropyl)- 5(6) - sulphobenzimidazole, 2 - phenylthiomethyl- 5(6) - sulphobenzimidazole, 2 - (tetrahydro - 2 - thienyl) - 5(6) - sulphobenzimidazole, bis - (5(6) - sulpho - 2 - benzimidazolylmethyl) sulphide and 2 - phenylselenomethyl - 5(6) - sulphobenzimidazole are prepared similarly starting from 3,4-diaminobenzenesulphonic acid. 2-(o-Methylthiophenyl) - 5(6) - sulphobenzimidazole is prepared by heating 3,4-diaminobenzenesulphonic acid and o-(methylthio) benzoic acid in polyphosphonic acid. 2-Methylthiomethyl-5(6)-carboxybenzimidazole hydrochloride is prepared by refluxing 3,4-diaminobenzoic acid hydrochloride and methylthio-acetic acid in 6N hydrochloric acid. 2 - (3 - Sulphopropylthiomethyl) benzimidazole, 2 - [2 - (3 - sulphopropylthio) ethyl]- benzimidazole, 2 - (3 - sulphopropylthiomethyl) - 5(6) - sulphobenzimidazole, 2 - [3 - (3 - sulphopropylthio) propyl] - benzimidazole, 2 - (3 - sulphopropylthiomethyl) - 5(6) - carboxybenzimidazole, 2 - [o - (3 - sulphopropylthio) phenyl] - #<SP>2</SP> - imidazoline and 3 - (3 - sulphopropylthio) - 5 - methylthiomethyl - 1H - 1,2,4 - triazole are prepared by refluxing the corresponding starting material with sodium methylate in methanol and propanesultone (giving the 3-sulphopropyl group). 2 - (4 - sulphobutylthiomethyl) benzimidazole and 2 - (1,3 - dimethyl - 3 - sulphobutylthiomethyl) benzimidazole are prepared by refluxing 2-mercaptomethylbenzimidazole and sodium methylate in methanol with butanesultone and 1,1,3-trimethylpropanesultone, respectively. 2 - Carboxymethylthiomethylbenzimidazole is prepared by adding an aqueous solution of sodium chloroacetate to a solution of 2-mercaptomethylbenzimidazole in IN sodium hydroxide. 2 - [2 - (Ethylthio) ethylthio] - 5(6) - sulphobenzimidazole is prepared by adding a solution of 2-chloroethylthioethane in dimethyl formamide to a solution of the disodium salt of 2 - mercapto - 5(6) - sulphobenzimidazole in dimethyl formamide and keeping at 80-90‹ C. for 3 hours. 2 - Allylthiomethyl - 5(6) - sulphobenzimidazole is prepared by heating the disodium salt of 2-mercaptomethyl-5(6)-sulphobenzimidazole and allyl chloride in dimethylformamide at 70‹ C. for 6 hours. 2-(α-Succinylthiomethyl) benzimidazole monohydrate is prepared by adding an aqueous solution of disodium α-bromosuccinate to a solution of 2- mercaptomethylbenzimidazole in 1N sodium hydroxide at 50‹ C. The potassium salt of 3-(3- sulphopropylthio) - 5 - [2 - (ethylthio) ethylthio] - 1H-1,2,4-triazole is prepared by refluxing a suspension of 3-(3-sulphopropylthio)-5-mercapto- 1H-1,2,4-triazole sodium salt in a solution of potassium in ethanol and chloroethylethylsulphide. The preparations of the following starting materials for the preparations above are also given. 2 - Mercaptomethyl - 5(6) - sulphobenzimidazole is prepared by refluxing 3,4-diaminobenzenesulphonic acid and mercaptoacetic acid in 6N hydrochloric acid. 2-(3-Mercaptopropyl)- benzimidazole is prepared by reducing at a hydrogen pressure of 1500 p.s.i. using Re 2 S 7  as catalyst bis - [3 - (2 - benzimidazolyl) propyl]- disulphide in ethylene glycol monomethylether. Bis - [3 - (2 - benzimidazolyl) propyl] - disulphide is prepared by refluxing o-phenylenediamine and bis-(3-carboxypropyl) disulphide in 6N hydrochloric acid. 2 - Mercaptomethyl - 5(6) - carboxybenzimidazole hydrochloride is prepared by refluxing 3,4-diaminobenzoic acid hydrochloride and mercaptoacetic acid in 6N hydrochloric acid. 1 - (Methylthio) acetylthio-semicorbazide is prepared by the addition of (methylthio)- acetyl chloride to a suspension of thiosemicarbazide in dry pyridine. The residue is cyclized to 5-methylthio-methyl-1H-1,2,4-triazole- 3-thiol by dissolving in methanol and adding sodium methylate and heating on a steam bath overnight.