Über 1-Alkyl-bzw. 1-Aryl-dihydro-6-methyl-2(1H)-pyrimidinthione

Reactions of resorcinol with substituted 3,4-dihydro-2(1H)-pyrimidinethiones

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The interaction between pyrimidinethiones and phenolic compounds was first examined by Zigeuner et al [1][2] It was found that pyrimidinethiones formed a product of addition at the 6-position of the pyrimidine ring upon boiling with a tenfold excess of 2,6-dimethylphenol in methanol with concentrated hydrochloric acid as a catalyst. Moreover, Zigeuner et al 1 noted that, when the reaction was performed with 2,4-xylenol under the same conditions, the main reaction product was 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane.

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“…Starting compounds 1 were synthesised according to published procedures. 1,2 The reaction time of the resorcinol alkylation by compounds 1 depends on the structure of the substituent R. The reaction rate depends on the capability of the substituent R to stabilise the intermediate carbocation. Compounds 1 in which R = H exhibited the highest rate of the reaction with resorcinol.…”