Department of Chemistry, University of Calcutta, University College of Science, Kolkata-700 009, India E-mail : sibdas2002@yahoo.co.in Manuscript received 24 November 2003, accepted 21 January 2004 3-Hydroxycoumarin, on reaction with hot formamide, produced 3-formylaminocoumarin (2) which underwent deformylation on fusion with p-toluenesulphonic acid monohydrate to produce very pure variety of 3- aminocoumarin. 4-Hydroxycoumarin and 4-hydroxybenzo[b]thiopyran-2-one (7) on similar reaction

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... ed benzo[l]pyrano[ 4,3-d]oxazol-4-one (6) and benzo[l]thiopyrano[ 4,3-d]oxazol-4-one (8) respectively, under effectively non-oxidising reaction condition.