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. 10, 2020
Filed:
Feb. 19, 2020
Kaken Pharmaceutical Co., Ltd., Tokyo, JP;
Masahito Watanabe, Fujieda, JP;
Takeshi Kanayama, Fujieda, JP;
KAKEN PHARMACEUTICAL CO., LTD., Tokyo, JP;
Abstract
The present invention provides efinaconazole producing and purifying methods adapted to industrial scale that provide high-purity efinaconazole in high yield by simple operations using specific impurities as indices. The efinaconazole producing method comprises: step A of forming a toluene solution comprising compound (II), compound (III), an inorganic base, and toluene in a volume (L) which is 2 to 5 times the mass (kg) of compound (II); step B of subjecting the toluene solution to reaction under heating; step C of washing the reaction mixture from step B to obtain a toluene solution of crude efinaconazole in which the residual amount of 4-MP is not more than 5 wt % of efinaconazole.