Patent ID: 8034981

Claim:
A process for producing a polyalkylene glycol derivative of the formula (11), comprising the following step (AA): Step (AA): a step of subjecting a compound represented by the formula (10) to a hydrogenative reduction reaction under a condition that a water content in a reaction system is 1% or less: wherein G is a residual group of a compound having 2 to 4 hydroxyl groups; R 2 is a hydrocarbon group having 1 to 4 carbon atoms; m1, m2, and m3 represent each average number of moles of an oxyethylene group added and satisfy the following relationship: 0 ≦m 1≦1000, 0 ≦m 2≦1000, 0 ≦m 3≦1000, 10 ≦m 1 +m 2 +m 3≦1000; X 1 is an amino group, a carboxyl group, or a protected group thereof; and g1, g2, and g3 represent each an integer and satisfy the following relational equations: 1 ≦g 1≦3, 0 ≦g 2, 0 ≦g 3, 2 ≦g 1 +g 2 +g 3≦4.