GB285389A - Manufacture of vat-dyestuffs of the 2-thionaphthene-3-indolindigo series - Google Patents

Abstract

285,389. I. G. Farbenindustrie Akt.- Ges. Feb. 14, 1927, [Convention date]. 2-Thionaphthene-3-indole-indigoid dyes are obtained by condensing 6-amino-oxythionaphthene with a 5 : 7-dihalogenisatin and then introducing two chlorine atoms into the 5 : 7-positions on the thionaphthene side by means of sulphuryl chloride, or by condensing 5: 7-dichlor-6-aminooxythionaphthene with a 5 :7-dihalogenisatin. According to examples, (1) , 6-amino-oxythionaphthene is condensed with 5 : 7-dibromisatin in acetic acid containing a little hydrochloric acid, or with 5: 7-dichlorisatin in alcohol in presence of sodium carbonate, and the product chlorinated with sulphuryl chloride in mono- or di-chlorbenzene : (2) 5 : 7-dichlor-6-amino-oxythionaphthene is condensed with 5 : 7-dibromisatin. The products dye cotton from the vat in brown shades of greater purity and fastness to kier-boiling than those given by the brown dyestuffs of Specification 28170/09. 5 : 7-Dichlor-6-amino-oxythionaphthene is obtained by chlorinating 4-nitro-1-aminobenzene, acetylating and reducing the resulting 4-nitro- 2 : 6-dichlor-1-aminobenzene to obtain 4-amino- 2 6-dichlor-1-acetylaminobenzene, and subjecting the latter to the action of sulphur chloride according to Specifications 17417/14 and 18292/14. The 2-amino-4 : 6-dichlor-5-acetylamino-1-thiophenol is treated with chloracetic acid to obtain the corresponding thioglycollic acid which yields the thionaphthene, by ring closure, by the methods of Specification 11173/06. The Specification as open to inspection under Sect. 91 (3) (a) comprises also the introduction of chlorine into the 6-amino-2-thionaphthene-5: 7- dihalogen-3-indole-indigo, by any means. This subject-matter does not appear in the Specification as accepted.