1495228 Preparation of diketo-peperazine FIRMENICH SA 28 June 1976 [2 July 1975 17 Oct 1975] 29264/77 Divided out of 1495227 Heading C3H A diketo-peperazine of Formula I is prepared by cyclizing aspartame by means of an acidic cyclizing agent in a suspension or solution of an aliphatic alcohol having 1 to 5 carbon atoms and subsequently treating the resulting reaction mixture with ammonia. The acidic cyclizing agent is preferably an acidic diatomaceous earth and the alcohol preferably is methanol and the reaction carried out at 100‹ to 150‹ C.
