公开(公告)号：US12018120B2

公开(公告)日：2024-06-25

申请号：US17436738

申请日：2020-03-25

申请人： NOF CORPORATION

发明人： Shota Sasaki ,  Yuichi Takahashi ,  Atsushi Sato ,  Tsuyoshi Takehana ,  Toshihiko Hagihara

IPC分类号： C08G65/332

CPC分类号： C08G65/3322

摘要： A method for producing a terminal carboxyl group-containing polyethylene glycol, which includes the following steps 1 and 2. Step 1: In a solution containing a polyethylene glycol having a hydroxyl group, an inorganic base 0.5 to 4 times the polyethylene glycol in mass, an aprotic solvent and water, mass of the water being 5 to 20 meq with respect to the inorganic base and mass of the water in the solution being 2,000 ppm or less, a compound of the formula (1) is reacted with the polyethylene glycol to obtain a polyethylene glycol ester:




wherein X represents a leaving group, a represents an integer of 4 to 9, and R1 represents a hydrocarbon group having 1 to 4 carbon atoms; Step 2: The polyethylene glycol ester is hydrolyzed to obtain a terminal carboxyl group-containing polyethylene glycol.