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:
Nov. 12, 1985
Filed:
Dec. 07, 1983
Applicant:
Inventors:
Shinsuke Fukuoka, Okayama, JP;
Tomonari Watanabe, Okayama, JP;
Assignee:
Asahi Kasei Kogyo Kabushiki Kaisha, Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07C / ; C07C / ;
U.S. Cl.
CPC ...
560 25 ; 560 21 ; 2604 / ;
Abstract
A process for producing a diphenylmethane dicarbamate by reacting an N-phenylcarbamate with a methylenating agent is disclosed. The process is carried out by condensing N-phenylcarbamate in two steps using a combination of two different types of acid catalysts. The catalysts exhibit a strong catalyzing effect and yet can be readily separated from the reaction mixture. The process produces dineuclear diphenylmethane dicarbamates in high selectivity. The acid catalysts can be easily recovered from the reaction mixtures and put to another use.