Reactions between 4-pyrimidones and sulphur ylides; cyclopropanation and ring opening reactions

Abstract

The reaction between 3-substituted 4-pyrimidones (4) and dimethylsulphoxonium methylide gives in some cases diazabicyclohept-2-enones (cyclopropapyrimidones)(13). An important side reaction is ring opening to give (Z)-3-aminoacrylamides (12); in the case of compound (4f) a major product is the oxopyrimidinyl ylide (16). Some attempts to open the cyclopropane ring in compound (13b) are described. A number of new bis(oxopyrimidinyl)ethanes (7)–(9) have been obtained.