GB307306A - Process for the manufacture of new anthraquinone derivatives - Google Patents

Abstract

307,306. I. G. Farbenindustrie Akt.- Ges. March 3, 1928, [Convention date]. Samples furnished. Anthraquinone vat dyes. - 5-Amino-4<1>-acylamino-1: 1<1>-anthrimidocarbazoles, and their aerivatives containing substituents, such as alkoxyl and hydroxyl groups, in the anthraquinone nuclei, are obtained by saponifying the corresponding diacylamino compounds under relatively mild conditions, whereby the acylamino group in the 5-position is saponified, while that in the i-position remains intact. For this purpose, the diacylamino compounds may be treated with alcoholic caustic alkali of 8-15 per cent strength and at a temperature between about 100-120‹ G., or, preferably, heated in sulphuric acid to a temperature not exceeding 60‹ G. The products are dark-brown powders which may be used as vat dyes, dyeing cotton in reddish shades, fast to chlorine, or as intermediates for the manufacture of dyes. In examples, (1) 5: 4<1>-dibenzoyldiamino-1: 1<1>-anthrimidocarbazole is saponified by means of sulphuric acid; the product, when diazotized and boiled with alcohol, yields 4- benzoylamino - 1 : 11 - anthrimidocarbazole, (2) 5 ' 4<1> dibenzoyldiamino-8-methoxy-1 : 1'-anthrimidocarbazole (Specification 298,696) is saponified with sulphuric acid, and (3) 5: 4'-diacetyldiammo-1 : 1'-anthrimidocarbazole is saponified by heating with alcoholic potash in an autoclave. Specification 29352/10 also is referred to. The Specification as open to inspection under Sect. 91 (3) (a) also mentions the preparation of halogen derivatives of 5-amino-4-acylamino-l : 1'- anthrimidocarbazoles; this subject-matter does not appear in the Specification as accepted.