Part 7: Synthesis of Some New 1,5-Benzodiazepines Fused with Different Heterocyclic Moieties

Abstract

3-cyano-1,11-dihydro-4,5-diphenyl-2-thioxopyrido[2,3-b](1,5)benzodiazepine 2 and 3-(2′-cyano-1′-phenyl-2′-ethanethiocarboxamide)-4-phenyl-1(H)(1,5)benzodiazepin2-one 3 were prepared via the reaction of 1,3-dihydro-4-phenyl-(1,5)benzodiazepin-2-one 1 with benzylidenecyanothioacetamide. Compound 2 was treated with halo compounds to give the corresponding S-alkylated compounds 4 _a−c, which underwent as intramolecular ring closure to thieno[3,2.5,6]pyrido[2,3-b](1,5)benzodiazepines 5 _a−c under PTC conditions. One-pot syntheis of compounds 5 _a−c was achieved via the reaction of compound 2 with the appropriate halo compound under PTC conditions. Compound 1 and 1-ethyl-4-phenyl-(1,5)benzodiazepin-2-one 9 were treated with carbon disulfide or phenylisothiocyanate and active nitriles to afford 4-thioxothiopyrano[4,3-b](1,5)benzodiazepines 8 and 10–14. Treatment of compound 10 with phenylisothiocyanate or acetic anhydride yielded oxazino-and pyrimido[4,5-b]thiopyrano-[4′,3′-b′](1,5)benzodiazepine 15 and 17. The reaction of compound 1 with elemental sulfur and active nitriles yielded thieno[3,2-b](1,5)benzodiazepines 18–21, respectively.

Keywords:

• 3-cyano-1,11-dihydro-4,5-diphenyl-2-thioxopyrido[2,3-b](1,5)benzodiazepine
• 1-ethyl-1(H)-4-phenyl-1,5-benzodiazepin-2-one
• PTC

Notes

^a Uncorrected.

^b Satisfactory microanalysis obtained, C, ±0.35; H, ±0.4; N, ±0.2; S, ±0.2.

^c Measured by a Nicolet FT-IR 710 spectrophotometer.

^d Measured by a Varian EM 360 L spectrometer at 60 MHZ using TMS as a internal standard and DMSO as a solvent.