AN EFFICIENT, GREEN, CATALYST FREE SYNTHESIS AND CRYSTALLOGRAPHIC STUDY OF BENZO-4H-PYRANS IN AQUEOUS MEDIUM

摘要

A highly efficient and environmentally benign for the synthesis a of 2-amino-7-hydroxy-4-aryl-4 H -chromene-3-carbonitrile derivatives (4a-n) in good to high yields (90%-97%) by one-pot three-component Michael addition reaction of malononitrile, aromatic aldehydes and resorcinol under reflux condition was developed in aqueous medium. Single crystal X-ray studies show that 4h crystallizes in the formula Csub22/subHsub15/subClsub2/subNsub2/subOsub2, /sub Mr= 410.26, Monoclinic, Space group P2(1)/c, a=12.753(9)?, b=6.665(4)?, c=24.050(14) ?, β=102.95(3)A° and 4i Csub16/subHsub10/subClsub2/subNsub2/subOsub2, /sub Mr= 333.16, Triclinic, Space group P-1, a=6.271(3)?, b=18.697(5)?, c =13.794(7) ?, β =94.269(17)A°. The structure of the products were further confirmed by sup1/supH NMR, sup13/supC NMR, IR and Mass spectrum.