SYNTHESIS OF NEW SUBSTITUTED 3-MERCAPTO-l,2,4-TRIAZOLES POSSESSING 5-H-DIBENZO[fl,rf]CYCLOHEPTENE MOIETIES

摘要

Seven new thiosemicarbazides 2a-g bearing 5H-dibenzo[a,d]cycloheptenyl-methyl group at N~1 and different alkyl or aryl substituents at N~4 were synthesized using classical procedures. ~1H-NMR analysis indicated the existence of two conformational isomers, a major axial (about 75%) and a minor equatorial one (25%) which are interconvertible by middle ring inversion. Cyclization of 2a-g in NaOH solution afforded the corresponding 3-mercapto-l,2,4-triazoles 3a-g which were separated as pure axial isomers. All the new compounds were extensively characterized by IR-, UV-, ~1H-NMR and ~(13)C-NMR spectroscopy and will be screened as carbonic anhydrase inhibitors in order to test the application of "bulky scaffold" strategy in this class of compounds.