Method for purifying an amino acid-n-carboxy anhydride

    公开(公告)号:US10975042B2

    公开(公告)日:2021-04-13

    申请号:US16418154

    申请日:2019-05-21

    IPC分类号: B01D9/00 C07D263/44

    摘要: The present invention is a method for purifying an NCA, including the steps of: a) dissolving an NCA contaminated with impurities into a solvent which is a good solvent and is not a chlorinated solvent followed by stirring to precipitate an undissolved impurity to afford a suspension, b) adding an acidic filter aid having ability to trap a basic impurity to the obtained suspension followed by filtration and/or forming a fixed bed of the acidic filter aid having ability to trap a basic impurity followed by filtering the suspension to bring the suspension to be in contact with the acidic filter aid having ability to trap a basic impurity, and c) adding the obtained filtrate dropwise to a poor solvent for NCA to crystallize out the NCA in which the impurities are removed. This makes it possible to purify a low-purity NCA conveniently to afford a high-purity NCA.

    Method for producing polyalkylene glycol derivative having amino group at end

    公开(公告)号:US10377775B2

    公开(公告)日:2019-08-13

    申请号:US14959088

    申请日:2015-12-04

    摘要: A method simply produces a narrowly distributed and high-purity polyalkylene glycol derivative having an amino group at an end without using a heavy metal catalyst. A method for producing a polyalkylene glycol derivative having an amino group at the end by reacting a compound represented by the general formula (V) with an alkylene oxide, then reacting a reaction product with an electrophile represented by the general formula (I), and deprotecting the obtained product without using a heavy metal: RA3O(RA4O)k-1RA4O−M+  (V) wherein RA3 represents a linear, branched, or cyclic hydrocarbon group having 1 to 20 carbon atoms; RA4 represents an alkylene group having 2 to 8 carbon atoms; k represents an integer of 2 to 5; and M represents an alkali metal; wherein RA1a and RA1b each independently represent a protective group of the amino group, or one of RA1a and RA1b represents H and the other represents a protective group of the amino group, or RA1a and RA1b bind to each other to form a cyclic protective group, and the protective group is deprotectable without using a heavy metal; RA2 represents a linear, branched, or cyclic hydrocarbon group having 1 to 6 carbon atoms; and X represents a leaving group.