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:
Mar. 16, 2021
Filed:
Mar. 22, 2018
Nof Corporation, Tokyo, JP;
Hiroki Yoshioka, Kawasaki, JP;
Yuji Yamamoto, Kawasaki, JP;
NOF CORPORATION, Tokyo, JP;
Abstract
A method of producing a polyoxyethylene derivative (1): where L1 is a divalent linker, X is a functional group capable of reacting with a physiologically active substance, a is 1 or 2, and n is from 11 to 3,650. The method includes Step (A): protecting 4 or 6 hydroxyl groups in a polyhydric alcohol having 5 or 7 hydroxyl groups by cyclic benzylidene acetalization to obtain a compound having a hydroxyl group at a 1-position and a protective group of a cyclic benzylidene acetal structure; Step (B): polymerizing from 11 to 3,650 moles of ethylene oxide to the compound obtained in the step (A) to obtain a polyoxyethylene derivative; Step (C): converting the hydroxyl group at a terminal of the polyoxyethylene derivative to a functional group capable of reacting with a physiologically active substance; and Step (D): deprotecting the protective group of the polyoxyethylene derivative.