Popis: |
5,6-Dihydro-2-phenyl-3-thiobenzoyl-2H-naphtho[1,2-b]thiin (8a) and the related dienic thioketones were synthesized in 3 steps starting from 2-(phenylthio)methylenetetralin-1-thione with chalcone, 4′-chrolochalcone, 4′-methoxychalcone, 2-cinnamoylthiophen, 2-cinnamoylfuran, 1-phenyl-2-buten-1-one, and acrylophenone respetively. Similarly, 3-thiobenzoyl-2,6-diphenyl-2H-thiin (8i) was synthesized from 1-phenyl-3-phenylthio-2-propene-1-thione. All of these dienic thioketones were found to exist in stable monomeric form. The conjugated dienic thioketone (8a) reacted as α,β-unsaturated thioketone with 2-norbornene, 2,5-norbornadiene, diethyl azodicarboxylate, diphenyl fumarate, N-phenyl- and N-(p-tolyl)maleimides, 2-chloroacrylonitrile, methyl methacrylate, acrylonitrile, and styrene to give the corresponding [4+2]cycloadducts. The thioketone (8i) also reacted with 2-norbornene to give the corresponding cycloadduct. The reaction provides a useful method for the syntheses of various sulfur-containing heterocycles. |