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The direction of heterocyclization of 4-hydrazino-5,6,7,8-tetrahydro [1] benzotieno [2,3-d] pyrimidine in reaction with dicarboxylic acid anhydride
Authors: D.O. Kolomieitsev, S.A. Varenichenko, V.O. Astakhina, V.I. Markov, S.I. Kovalenko, O.V. Kharchenko
Number of views: 348
Sulphur-containing fused pyrimidines, in particular thienopyrimidines, exhibit wide spectrum of biological activities which stimulates investigation of synthesis and reactions of these compounds. Our previous studies on new series of R1,R2-thieno [2,3-d] pyrimidine-4(3H)-one, thio(seleno)ne derivatives showed that some of obtained compounds have good antimicrobial activity. Another derivative of benzothieno [2,3-d] pyrimidine, 4-hydrazino-5,6,7,8-tetrahydro [1] benzothieno [2,3-d] pyrimidine 3, contains several reactive centers and the heterocyclization reactions can occur in different directions depending on the nature of cyclizing reagents. This paper reports the result of interaction of different dicarboxylic acid anhydrides (maleic, phthalic and endic anhydrides) with the multifunctional compound 4-hydrazino-5,6,7,8-tetrahydro [1] benzothieno [2,3-d] pyrimidine 3 to form novel heterocyclic compounds. The intermediate compounds of cyclization have been identified. The reaction was stated to occur either with intramolecular nucleophilic addition (for maleic anhydride) or with the formation of imid derivatives (for phthalic and m-nitrophthalic anhydrides) depending on the nature of dicarboxylic acid anhydride. The interaction of hydrazine 3 with endic anhydride occurs in one step. The new compounds were characterized by 1H NMR spectroscopy, mass spectrometry and elemental analysis.