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:
May. 21, 2002
Filed:
Sep. 26, 1997
Mitsui Chemicals, Inc., , JP;
Abstract
A process for preparing a hydroxybenzoic acid is herein disclosed which comprises reacting a phenol with an alkali metal compound by the use of an aprotic polar organic solvent as a reaction solvent to form an alkali metal salt of the phenol, and then reacting this alkali metal salt with carbon dioxide to obtain a hydroxybenzoic acid, said process comprising the step of carrying out the reaction under conditions that a molar ratio of the phenol to the total of the alkali metal compound and the aprotic polar organic solvent is larger than 1. Furthermore, the process may contain the steps of precipitating crystals from the reaction solution, separating the solid from the solution to obtain a wet alkali metal salt of the hydroxybenzoic acid, dissolving the wet alkali metal salt in water, and precipitating crystals from the solution by acidification to obtain the hydroxybenzoic acid.