AMINO-ACIDS AND PEPTIDES .46. INTRODUCTION OF CARBOXYL FUNCTION INTO PYRAZINONE BY USING NEWLY DEVELOPED PROCEDURE FOR PYRAZINONE RING FORMATION - OBSERVATION OF IMMEDIATE DECARBOXYLATION

The carboxyl function was easily introduced into a pyrazinone ring by means of a newly developed procedure for pyrazinone ring formation fro m Asp- or Glu-containing dipeptidyl chloromethyl ketones: during the r eaction, rapid decarboxylation from a carboxymethyl group at position 3 of 2(1H)-pyrazinone occurred due to the low electron density at posi tion 3 of 2 (1H)-pyrazinone.