Reaction of Dimethyl Sulfoxide with 4-Acyloxycoumarins |
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Authors: | Tabassum Ara Khaliquz Zaman Khan Khalida Tasneem |
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Affiliation: | 1. Department of Chemistry , National Institute of Technology , Srinagar, India saithfb7@rediffmail.com;3. Department of Chemistry , University of Kashmir , Srinagar, India;4. Department of Chemistry , Northeastern Regional Institute of Science and Technology , Nirjuli, India |
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Abstract: | Dimethyl sulfoxide converts 4-acetoxycoumarin (1) exclusively to 2-(2-hydroxybenzoyl)-2-[(methylthio)methyl]-2,3-dihydro-4 H-furo[3,2-c]chromen-4-one (3) at 180°C under a nitrogen atmosphere, but in the absence of nitrogen, the products obtained are dicoumarol and its dehydrative cyclization products 7 H-bis[1]benzopyrano[4,3-b: 3′,4′-c]pyran-6,8-dione (9) and (3). Under similar conditions, 4-benzoyloxycoumarin (1a) affords benzoic acid, 4-hydroxy-3-({2-[(methylthio)methyl]-3-oxo-2,3-dihydro-1-benzofuran-2-yl}methyl)-2H-chromen-2-one (7), and 3-(2-hydroxybenzoyl)-3,4-dihydro-2H,5H-pyrano[2,3-b] chromen-5-one (8). |
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Keywords: | 4-Acetoxycoumarin 4-benzoyloxycoumarin DMSO |
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