Method for producing biodegradable polyoxyalkylene derivative

A method for producing a biodegradable polyoxyalkylene derivative, which comprises:

• reacting a biodegradable polyoxyalkylene compound represented by the following formula (1):
• wherein Z represents a residue of a compound having from 2 to 10 hydroxyl groups;
• Y represents a single bond or a group selected from the group consisting of an alkylene group having from 1 to 6 carbon atoms, —C(═O)—, —C(═O)O—, —C(═O)(CH2)p—, in which p is from 1 to 5, —C(═O)(CH2)qC(═O)O—, in which q is 2 or 3, —(CH2)2NHC(═O)(CH2)2— and —(CH2)3NHC(═O)(CH2)2—;
• X represents a group selected from the group consisting of a carboxyl group, a maleimide group, a t-butoxycarbonylamino group and a 3,3-diethoxypropoxy group;
• R represents a hydrocarbon group having from 1 to 6 carbon atoms;
• AO represents an oxyalkylene group having from 2 to 4 carbon atoms;
• a is from 1 to 500, and b is from 0 to 500;
• m1 and m2 are each independently from 5 to 2000;
• m3 is from 0 to 2000;
• n1 is from 1 to 5, and n2 is from 0 to 1;
• and
• k1 is from 0 to 8, k2 is from 0 to 8 and k3 is from 1 to 10, k1, k2 and k3 satisfy a relationship, 2≦k1+k2+k3≦10;
• with a compound represented by the following formula (I-1) in the presence of potassium carbonate;
• wherein t is from 1 to 2;
• the biodegradable polyoxyalkylene derivative being represented by the following formula (2):
• wherein Z represents a residue of a compound having from 2 to 10 hydroxyl groups;
• Y represents a single bond or a group selected from the group consisting of an alkylene group having from 1 to 6 carbon atoms, —C(═O)—, —C(═O)O—, —C(═O)(CH2)p—, in which p is from 1 to 5, —C(═O)(CH2)qC(═O)O—, in which q is 2 or 3, —(CH2)2NHC(═O)(CH2)2— and —(CH2)3NHC(═O)(CH2)2—;
• X represents a group selected from the group consisting of a carboxyl group, a maleimide group, a t-butoxycarbonylamino group and a 3,3-diethoxypropoxy group;
• R represents a hydrocarbon group having from 1 to 6 carbon atoms;
• AO represents an oxyalkylene group having from 2 to 4 carbon atoms;
• a is from 1 to 500, and b is from 0 to 500;
• m1 and m2 are each independently from 5 to 2000;
• m3 is from 0 to 2000;
• n1 is from 1 to 5, and n2 is from 0 to 1;
• and
• k1 is from 0 to 8, k2 is from 0 to 8 and k3 is from 1 to 10, k1, k2 and k3 satisfy a relationship, 2≦k1+k2+k3≦10;
• and
• G represents a residue originating in a compound represented by the formula (I-1), provided that in a case where k3 is 2 or more, at least one G may be a hydrogen atom.