Patent ID: 8445544

Claim:
A process for the preparation of a compound of formula (2) said process comprising the step of subjecting a compound of formula: and an intermediate compound having a formula to a coupling reaction to form the compound of formula (2), wherein PSA is polysialic acid; R 1 is at each occurrence independently a (C 1 -C 8 )-alkyl; R 2 is independently selected from the group consisting of —C(O)NR—, —C(O)NR—(C 1 -C 8 )-alkyl-NR—, —NRC(O)— and —NRC(O)—(C 1 -C 8 )-alkyl-NR, R is independently either hydrogen or (C 1 -C 8 )-alkyl; X is —SO 3 —R 3 ; R 3 is independently selected from the group consisting of hydrogen, (C 1 -C 8 )-alkyl and (C 1 -C 8 )-alkyl-R 4 ; R 4 is a polymer, n is an integer selected from 0, 1, 2, 3, or 4; and m is an integer selected from 1, 2, 3, or 4.