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:
Apr. 06, 1999
Filed:
Nov. 13, 1997
Ube Industries, Ltd., Yamaguchi, JP;
Abstract
Disclosed is a process for preparing 4-fluoro-3-trifluoromethylphenol from 4-fluoro-3-trifluoromethylaniline, which comprises the steps of (1) using about 1 to 20 parts by weight of water based on 1 part by weight of 4-fluoro-3-trifluoromethylaniline in the presence of sulfuric acid to obtain 4-fluoro-3-trifluoromethylaniline sulfate; (2) subjecting the obtained 4-fluoro-3-trifluoromethylaniline sulfate to a diazotization reaction by using a diazotizing agent to obtain an aqueous solution containing about 8 to 25% by weight of a 4-fluoro-3-trifluoromethylbenzene-diazonium salt where a sulfuric acid concentration after diazotization is about 30 to 70% by weight in terms of the amount of sulfuric acid added, and the amount of water used is about 1 to 20 parts by weight based on 1 part by weight of 4-fluoro-3-trifluoromethylaniline; and (3) hydrolyzing the obtained 4-fluoro-3-trifluoromethylbenzenediazonium salt where a sulfuric acid concentration is about 30 to 70% by weight in terms of the amount of sulfuric acid added in a copper sulfate aqueous solution.