Patent GB-517457-A (GB)
Title: Manufacture of sulphur-containing organic compounds
Filed: 1938-06-27
Abstract: 517,457. Sulphoxides sulphones. ELLING- WORTH, S., ROSE, F. L., and IMPERIAL CHEMICAL INDUSTRIES, Ltd. June 27, 1938. Nos. 16703 and 13248. Divided out of 517,421. [Class 2 (iii)] Sulphoxides and sulphones of the general formula where X may be >S=O or >S # and R hydrogen, an aliphatic, aliphatic-aromatic, or aromatic radical are prepared by reducing the nitro group of the corresponding 4-nitro-4<1>- acyl-aminodiphenyl-sulphoxide or -sulphone, or by causing an acid or acids of the formula R-COOH or a functional derivative of such an acid to react with 4:4<1>-diaminodiphenyl-sulphoxide or -sulphone, or in the case of the sulphoxides oxidizing the corresponding 4-amino-4<1>- acylaminodiphenyl sulphide. Functional derivatives of the acids R-COOH include the anhydrides, acid halides or esters such as methyl or ethyl esters of the acid. Reducing agents for the nitro compounds mentioned include iron and hydrochloric acid, zinc dust and acetic acid, or stannous chloride. and hydrochloric acid. The oxidizing agent for the sulphides which is preferred is hydrogen peroxide in solution in aqueous acetic acid. In examples (1) 4 - nitro - 4<1> - acetylaminodiphenyl sulphone prepared by oxidizing 4-nitro-41-acetylaminodiphenyl sulphide with hydrogen peroxide or chromic acid in hot glacial acetic acid is reduced in aqueous-alcohol solution with iron borings and hydrochloric acid to give 4-amino- 41-acetylaminodiphenyl sulphone ; (2) 4-nitro- 4<1>-acetylaminosulphone is reduced in glacial acetic acid solution with zinc dust to give 4- amino-4<1>-acetylaminodiphenyl sulphone ; (3) 4 - nitro - 4<1> - formylaminodiphenyl sulphone is reduced in aqueous-alcohol solution with iron borings and hydrochloric acid to give 4-amino- 41-formylaminodiphenyl sulphone. The starting material in this example is preferably made by heating 4-nitro-4<1>-aminodiphenyl sulphide with formic acid and oxidizing the formyl compound so produced with hydrogen peroxide in acetic acid solution ; (4) 4-nitro-4<1>-benzoylamino-diphenyl sulphone prepared by heating 4-nitro-4<1>-amino-diphenyl sulphone with benzoyl chloride is reduced in alcohol solution with iron borings and hydrochloric acid to give 4- amino-4<1>-benzoylaminodiphenyl sulphone ; (5) 4-amino-4<1>-acetylaminodiphenyl sulphide is oxidized in aqueous-acetone solution with hydrogen peroxide to give 4-amino-4'-acetylaminodiphenyl sulphoxide ; (6) 4-41-diaminodiphenyl sulphone is treated with acetic anhydride in acetone solution, acidified with hydrochloric acid and filtered from 4:4<1>-diacetyldiaminodiphenyl sulphone produce as a by-product and the filtrate crystallized to give 4-amino-41- acetylaminodiphenyl sulphone; (7) 4:41-diaminodiphenyl sulphone is boiled for some time in acetic acid solution to give the same mixture as is obtained in example (6) which is worked up in a similar manner; (8) 4:4'- diaminodiphenyl sulphone is treated in acetone solution with acetyl chloride to give the same mixture of products as obtained in example (6), and the desired 4-amino-4<1>-acetylaminodiphenyl sulphone is separated by treatment with boiling methanol.