The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 25, 1989
Filed:
May. 28, 1987
Werner Brodt, Hattersheim am Main, DE;
Theodor Papenfuhs, Frankfurt am Main, DE;
Hoechst Aktiengesellschaft, Frankfurt am Main, DE;
Abstract
Process for the preparation of 2-nitro-4-sulfamyldiphenylamine dyestuffs of the formula (1) ##STR1## in which R.sub.1 and R.sub.2 each denote a hydrogen, chlorine or bromine atom or a C.sub.1 -C.sub.4 -alkyl or C.sub.1 -C.sub.4 -alkoxy group or a phenoxy group which can be substituted on the benzene nucleus by chlorine or bromine atoms or C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -alkoxy or trifluoromethyl groups, or denote a naphthoxy group, and R.sub.2 can also be an -N-(C.sub.1 -C.sub.4 -alkyl).sub.2, -NH-(C.sub.1 -C.sub.4 -alkyl), -NH-(C.sub.1 -C.sub.4 -alkanoyl) or -NH-benzoyl group, and R.sub.3 and R.sub.4 each denote a hydrogen atom or a C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.2 -alkoxy-C.sub.1 -C.sub.4 -alkyl or C.sub.5 -C.sub.6 -cycloalkyl group, and R.sub.4 can also be a phenyl group which can be substituted by chlorine or bromine atoms or C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -alkoxy, -N-(C.sub.1 -C.sub.4 -alkyl).sub.2, -NH-(C.sub.1 -C.sub.4 -alkyl), -NH-(C.sub.1 -C.sub.4 -alkanoyl), -NH-benzoyl, phenoxy or naphthoxy groups, by sulfonating o-nitrochlorobenzene with chlorosulfonic acid at 100.degree.-110.degree. C. to give 4-chloro-3-nitrobenzenesulfonic acid of the formula (2) ##STR2## converting the latter by means of thionyl chloride at 70.degree.-80.degree. C. into 4-chloro-3-nitrobenzenesulfochloride, precipitating the latter on ice and subjecting the resulting 4-chloro-3-nitrobenzenesulfochloride to a condensation reaction first with an aliphatic or aromatic amine of the formula ##STR3## in which R.sub.1, R.sub.2, R.sub.3 and R.sub.4 have the meanings mentioned, suspended or dissolved in an aqueous solution of a basic condensation agent, the presence of an ionic or nonionic surfactant, initially at 5.degree. to 50.degree. C. and at pH 7.5 to 12.5, and then with an aromatic amine of the formula (4) mentioned, suspended or dissolved in an aqueous solution of a basic condensation agent, at 80.degree. to 100.degree. C., within the pH range mentioned and in the presence of a surfactant of the type mentioned.