Three-component one-pot synthesis of N-arylsulfonyl-2-iminocoumarins

A one-pot, synthesis of N-arylsulfonyl-2-iminocoumarins is developed at ambient temperature by the reaction of 2-hydroxybenzaldehydes, arylacetonitriles, and aryl sulfonyl chlorides using DABCO as a base in a bio-mass-derived green solvent 2-MethylTHF. A simple telescoped process in which 2H-chromen-2-imines are formed in situ by the condensation of 2-hydroxybenzaldehyde and arylacetonitriles. The formed imines are further reacted with arylsulfonyl chlorides in a one-pot approach to obtain the target compounds. This protocol provides access to 3-aryl-N-arylsulfonyl-2-iminocoumarins in a practical and environmentally benign way avoiding cumbersome steps of intermediate syntheses and purifications.