Srikanta Samanta

Synthesis of bioactive heterocycles: tandem reaction of 4-N-(4′-aryloxybut-2′-ynyl),N-methylaminocoumarin with 3-chloroperoxybenzoic acid

A number of 4-N-(4′-aryloxybut-2′-ynyl),N-methylaminocoumarins (4a–e) on treatment with one equivalent of 3-chloroperoxybenzoic acid at 0–5°C for 10 min and then stirring at rt for 10 h afforded pyrrolo[3,2-c]coumarin derivatives in 70–75% yields. The 4-N-(4′-aryloxybut-2′-ynyl),N-methylaminocoumarins 4a–e were in turn prepared from 4-tosyloxycoumarin (2) and (4-aryloxybut-2-ynyl)-N-methylamine (3a–e).

An unusual one-pot synthesis of 3-benzoylcoumarins and coumarin-3-carbaldehydes from 2-hydroxybenzaldehydes under esterification conditions

Synthesis of 3-benzoylcoumarins and coumarin-3-carbaldehydes has been achieved in moderate to good yields (31–83%) by the reaction of easily available 2-hydroxybenzaldehydes and phenylpropiolyl chloride/propiolyl chloride under esterification condition.

Synthesis of Sulphur Compounds: Regioselective Synthesis of Thieno[2,3-b]thiophenes by Sulfoxide Rearrangement

A number of thieno[2,3-b]thiophenes have been successfully synthesized in a 50–55% yield by m-chloroperoxybenzoic acid–mediated tandem cyclization involving [2, 3] and [3, 3] sigmatropic rearrangements and an intramolecular Michael addition.