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. 13, 1997
Filed:
Dec. 07, 1994
Mitsuaki Yamada, Ibaraki, JP;
Katsuhide Okimi, Sakai, JP;
Katsuyuki Takahashi, Osaka, JP;
Norio Nagano, Osaka, JP;
Osaka Gas Company Limited, Osaka, JP;
Abstract
A fluorene derivative of high purity is produced by reacting fluorenone with phenoxyethanol in the presence of a sulfuric acid-thiol catalyst system, dissolving the reaction mixture in a lower aliphatic alcohol and adding water to the resulting solution for precipitation of 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene [fluorene derivative]. A fluorene derivative of still higher purity is obtained by recrystallization from a lower aliphatic alcohol. In accordance with this invention, a fluorene derivative can be produced advantageously on a commercial scale without incurring any appreciable loss of fluorenone, in good yield, with high efficiency and in a reduced production time.