Photoreaction of Arenecarbothioamides with 2-Vinylfuran Analogues. The Formation of Tetracyclic Indoles and 2, 3-Diaryl-2-pyrrolin-5-ones

Photoreaction of arenecarbothioamides (1) with 2-vinylfuran analogues (2, 6) in benzene aolution gave tetracyclic indole systems (3, 8) via photogenerated diarylethylene intermediates. In the case of reaction of furan- or thiophenecarbothioamide (1c, 1d) with 2-furanacrylic acid (2-i), 2, 3-diaryl-2-pyrrolin-5-ones (5c-i, 5d-i) were obtained.