Synthesis of 7-Hydroxy-6-alkyl-coumarins

Synthesis of p-hydroxy alkyl benzoates

Synthesis of Functionalized Coumarins

The synthesis of functionalized 2-oxo-2H-coumarin derivatives has been studied by a one-pot reaction of o-hydroxybenzaldehyde, ethyl 2-bromoacetate and triphenylphosphine in the presence of catalytic amount of triethyl amine in EtOAc, water or under solvent free conditions. We have found the best results obtained under solvent free condition.

Condensationtion of 3-hydroxy pyridine alkyl isocyanides and dialkyl acetylenedicarboxylate: synthesis of 4H-chromenes

The reactive intermediate generated by the addition of tert-butyl and 1,1,3,3-tetramethyl butyl isocyanide and cyclohexyl isocyanide to dialkyl acetylenedicarboxylate was trapped by 3-hydroxy pyridine to produce highly functionalized 4H-chromenes in fairly good  yields.

Reaction between 3-hydroxy pyridine alkyl isocyanides and dialkyl acetylenedicarboxylate: synthesis of 4H-chromenes

The reactive intermediate generated by the addition of tert-butyl and 1,1,3,3-tetramethyl butyl isocyanide and cyclohexyl isocyanide to dialkyl acetylenedicarboxylate was trapped by 3-hydroxy pyridine to produce highly functionalized 4H-chromenes in fairly good  yields.

Reaction between 3-hydroxy pyridine alkyl isocyanides and dialkyl acetylenedicarboxylate: synthesis of 4H-chromenes

The reactive intermediate generated by the addition of tert-butyl and 1,1,3,3-tetramethyl butyl isocyanide and cyclohexyl isocyanide to dialkyl acetylenedicarboxylate was trapped by 3-hydroxy pyridine to produce highly functionalized 4H-chromenes in fairly good  yields