[Preparation of N,N-bis(methylsulphonylethoxycarbonyl)insulins (author's transl)]

The preparation of N,N-bis(methylsulfonylethoxycarbonyl)insulins is described. In an aequeous buffer at pH 5.8 selectivity of the reaction of insulin with 20 equivalents of N-(methysulfonylethoxycarbonyloxy)succinimide (Msc-ONSu) leads very specifically to N alpha A 1,-N alpha B 1-(Msc)2 - insulin. The product can be isolated in a yield of 60%. Using N alpha A 1-citraconylinsulin the N alpha B 1, NEB29-(Msc)2 -insulin can be prepared in a yield of 40% based on insulin.