| Abstract: | Purine-8-thione ( 1 ) is acylated on nitrogen, not on sulfur as was previously reported. Thus, the reactions of 1 with ethyl chloroformate and with acetic anhydride yield, respectively, ethyl purine-8-thione-9( 7 )-carboxylate ( 3 ) and 9 ( 7 )acetylpurine-8-thione ( 7 ) as shown by independent synthesis and spectra. In like manner, benzimidazole-2-thione ( 10 ) reacts with acetic anhydride, ethyl chloroformate, benzoyl chloride, and cyclohexyl isocyanate to yield the corresponding N-acylated derivatives. In addition, 10 yields 1,3-dibenzoylbenzimidazole-2-thione on treatment with 2 equivalents of benzoyl chloride. |
