Efficient and Benign One-Pot Conversion of N-Tosyl-1,4,5,6-tetrahydropyrimidines to Pyrimidines via Tandem β-Elimination and Aromatization

Abstract

An efficient, mild, benign, and practical method for one-pot conversion of N-tosyl-1,4,5,6-tetrahydropyrimidines into pyrimidines is discussed in detail. In this method, N-tosyl-1,4,5,6-tetrahydropyrimidines are first prepared via N-tosylation of tetrahydropyrimidines with TsCl and then treated with 1.5 equivalents of NaOH in dimethylsulfoxide (DMSO) under air at 60 °C to afford corresponding pyrimidines in 70–95% yields via cascade β-elimination and aromatization.

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GRAPHICAL ABSTRACT

Keywords:

• Aromatization
• β-elimination
• nitrogen-containg heterocycles
• pyrimidines
• synthetic methods
• N-tosyl-1,4,5,6-tetrahydropyrimidines

ACKNOWLEDGMENTS

We thank the National Natural Science Foundation of China (No. 20972048) and the Shanghai Educational Development Foundation (Dawn Program No. 03SG27) for the financial support of this work.

Notes

^a Isolated yield.

^b Reflux.

^a Isolated yield.