Synthesis of Pyrimidine Derivatives and Their Related Compounds Using Ketene Dithioacetals

Ketene dithioacetals bearing electron-withdrawing groups are useful and versatile reagents for the synthesis of pyrimidine derivatives.This review article describes the synthetic usefulness and importance of ketene dithioacetals in the preparation of pyrimidines and fused pyrimidine derivatives.CONTENTS 1. 2 .3 Reactions of N-[Bis(methylthio)methylenelcy~namide with Active Methylene compound^ 2.4 Double Mannich Reactions 3. Construction of Pyrimidine-condensed Bicyclic Rings 3 .1 s-Triazolo[l.S-alpyrimidines 3 .2 Pyrido[2.3-dlpyrimidines3 .3 PyridoIl.2-alpyrimidines3 .4 Pyrimida[4.5-dlpyrimldines 4 .Construction of Pyrimidine-condensed Tricyclic Rings 5.