Efficient and Practical Syntheses of Benzothiopyran Derivatives
摘要:
Concise and inexpensive methods for the preparation of 4-hydroxy-1-thiocoumarin and 2-methylthiochromone from 2-mercaptobenzoic acid are described, which should be readily amenable to large scale synthesis.
Efficient and Practical Syntheses of Benzothiopyran Derivatives
摘要:
Concise and inexpensive methods for the preparation of 4-hydroxy-1-thiocoumarin and 2-methylthiochromone from 2-mercaptobenzoic acid are described, which should be readily amenable to large scale synthesis.
A novel short-step methodology to benzothiopyranone derivatives has been developed starting from an activated precursor, N-hydroxysuccinimide ester of thiosalicylic acid. The procedure is based on a tandem C-acylation-cyclisation process under mild reaction conditions in good yields. The structure elucidation has been established using X-ray crystallography and NMR spectral data. (C) 2008 Elsevier Ltd. All rights reserved.