Process for the preparation of the cholecystokinin-pancreozymin octapeptide amide sulfate ester

摘要

A process for the preparation of L-aspartyl-(O-sulfato-L-tyrosyl)-L-methionyl-glycyl-L-tryptophyl-L-met hionyl-L-aspartyl-L-phenylalanine amide, which comprises treating the protected octapeptide amide of the general formula (II) <IMAGE> wherein X is BOC, Cbz or Ddz, Y is OtBu, OBzl or OH and W is OtBu, OBzl or OH, in the presence of an ether with an excess of the complex compound of sulfur trioxide and a tertiary amine containing at least one alkyl group, converting the obtained sulfate ester of the protected octapeptide amide into an alkali metal salt and simultaneously removing the formyl group from the tryptophan unit by reacting the sulfate ester with an alkali metal hydroxide, and then splitting off the remaining protective groups by acidolysis.