PROCESS FOR THE PREPARATION OF A DIPEPTIDE AND INTERMEDIATE PRODUCT IN SUCH A PROCESS

摘要

Process for the preparation of an N-formyl-L-leucyl-L-tert.-leucine-N- methylamide in which N-formyl L-leucine is coupled to L-tert.-leucine-N- methylamide in the presence of an activating agent. Preferably, use is made of L-tert.-leucine-N-methylamide with an enantiomeric excess greater than 98 % and N-formyl-L-leucine with an enantiomeric excess greater than 98 %. If desired, the dipeptide obtained is subsequently deformylated and the resulti ng N-formyl-L-tert.-leucine-N-methylamide or the L-leucyl-L-tert.-leucine-N- methylamide is further subjected to one or more crystallizations. The invention also relates to the N-formyl-L-leucyl-L-tert.-leucine-N-methylamid e and the use of N-formyl-L-leucyl-L-tert.-leucine-N-methylamide in the preparation of pharmaceuticals.