Unique zeolite-catalyzed synthesis of nitroketene S,N-acetals

Abstract

Dimethyl carbonimidodithioates ( 4a–g, 7a–c) derived from various primary amines and amino acid esters [glycine, (L)-alanine and (L)-phenylalanine] have been condensed with nitromethane in the presence of the rare-earth exchanged zeolite RE(70%)Na Y to give the S,N-acetals ( 5a–g, 8a–c). Mercuric chloride catalyzed hydrolysis of these ( 8a–c) has led to the nitroacetyl derivatives ( 9a–c). The glycine derivative (7a) gives a dimeric product ( 11) when heated alone with the zeolite.