T. Yokoi et al., AMINO-ACIDS AND PEPTIDES .48. STUDIES ON THE STRUCTURE OF AN UNEXPECTED REACTION-PRODUCT FROM DIPEPTIDYL CHLOROMETHYL KETONE DURING ACID-HYDROLYSIS, Journal of chemical research. Synopses, (1), 1997, pp. 10-11
During the course of the synthesis of peptidyl chloromethyl ketones (C
MKs), it was revealed that aminoacid recovery after acid hydrolysis (6
mol dm(-3) HCl, 110 degrees C, 20 h) of dipeptidyl chloromethyl keton
es was markedly low (7.1-33.7%) owing to the formation of 5-methylpyra
zin-2(1H)-one derivatives during the acid hydrolysis.