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. 19, 1985
Filed:
Mar. 29, 1984
Yoshihiro Tasaka, Kamifukuoka, JP;
Toshihiro Nakamichi, Kamifukuoka, JP;
Yutaka Katsuhara, Kawagoe, JP;
Central Glass Company Limited, Ube, JP;
Abstract
Dehydrating decomposition of compound (I), i.e. gem-diol, hemi-acetal or hemi-ketal, by contact with sulfuric acid gives a carbonyl compound (II). ##STR1## Disclosed is a two-stage process in which the first stage is the contact of compound (I) with sulfuric acid at 90.degree.-140.degree. C. so as to partly decompose and dehydrate the compound (I), permitting the concentration of sulfuric acid to become lower than 93 wt. % but not lower than 65 wt. %, and the second stage is the contact of the product of the first-stage reaction with concentrated sulfuric acid at a temperature not higher than 60.degree. C., preventing the concentration of sulfuric acid from becoming lower than 93 wt %. For example, hexafluoroacetone is obtained from a hydrate thereof by this process using only a small amount of sulfuric acid.