Synlett 2004(11): 1909-1912  
DOI: 10.1055/s-2004-830858
LETTER
© Georg Thieme Verlag Stuttgart · New York

Sulphamic Acid - An Efficient and Cost-Effective Solid Acid Catalyst for the Pechmann Reaction

Pankajkumar R. Singh, Devendrapratap U. Singh, Shriniwas D. Samant*
Organic Chemistry Research Laboratory, University Institute of Chemical Technology, N. M. Parekh Marg, Matunga, Mumbai-400 019, India
Fax: +91(22)24145614; e-Mail: samantsd@udct.org;
Further Information

Publication History

Received 12 May 2004
Publication Date:
04 August 2004 (online)

Abstract

Sulphamic acid (H2NSO3H, SA) is used as an alternative to conventional acid catalysts in the Pechmann condensation of phenols with β-ketoester leading to the formation of substituted coumarin. The method is simple, cost-effective, solvent-free and gives good yields in a short reaction time.

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Typical Experimental Procedure: To the weighed quantity of phenol (10 mmol), and β-keto ester (10 mmol), the sulphamic acid (5 mmol) was added and the reaction mixture was stirred at 130 °C in a pre-heated oil-bath. After completion of the reaction at the desired time as indicated in Table [1] , the reaction mixture was poured into water and the resultant product was filtered. The products were further purified by column chromatography. The compounds are well known and in agreement with spectral and physical data.