Synthesis and S(RN)1 reactions in 5-nitrothiazole series

A new heterocyclic reductive alkylating agent, the 2-methyl-4-chloromethyl-5-nitrothiazole, has been synthesized and could react with the 2-nitropropane anion as nucleophile, to give the 2-methyl-4-(2-methylpropenyl)-5-nitrothiazole as the major product. The reaction was shown to proceed by the S(RN)1 mechanism which was confirmed by the classical criteria for S(RN)1 reaction: the leaving group effect, the electronwithdrawing group effect and classical inhibition experiments by dioxygen, p-dinitrobenzene, cupric chloride or di-tert-butylnitroxide. This reaction has been extended to nitrocyclopentane and nitrocyclohexane anions with lower yields. (C) 1997 Elsevier Science Ltd.