Mercaptopyrimidines, synthesis

The synthesis of 2-substituted pyrimidines from 1,3-dicarbonyl compounds and urea derivatives was first described by Evans2 and was later improved by Hunt, McOmie, and Sayer3 for the preparation of 2-mercapto-4,6-dimethylpyrimidine. Burness4 employed 3-ketobutyraldehyde acetal in this procedure to give 2-mercapto-4-methylpyrimidine. 2-Mercaptopyrimidine has been prepared from 1,1,3,3-tetraethoxypropane and thiourea by variations of this basic method 3 6 6 as well as by the reaction of 2-chloropyrimidine with thiourea 1 or sodium hydrosulfide.8... 

This preparation describes a convenient and general method of synthesis of substituted pyrimidines from compounds containing a /3-dicarbonyl group, either intact or as the corresponding ketal. The usefulness of the 2-mercaptopyrimidines is enhanced by the ease of removal of the mercapto group by desulfurization 9 or oxidation 10 and its replacement by other functional groups.1 ... 

Obirai J, Nyokong T (2005) Synthesis, spectral and electrochemical characterization of mercaptopyrimidine-substituted cobalt, manganese and Zn11 phthalocyanine complexes. Electrochim Acta 50(16-17) 3296-3304... 

Bridgedhead thiazolo[3,2-a]pyrimidines, and their isosteres occupy a unique place in medicinal chemistry due to their wide application as drug and drug-intermediates [7-11]. Several methods are known for synthesis of thiazolo[3,2-a]pyrimidine derivatives, from 2-mercaptopyrimidines and a-halo ketones, and by cyclocondensation of a-aminothiazoles with P-diketones, P-keto aldehydes, and their acetals, P-chlorovinyl ketones and aldehydes. 

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