Efficient atom economical one-pot multicomponent synthesis of densely functionalized 4H-chromene derivatives

A sequential one-pot, atom economical three component reaction yielding medicinally promising ethyl 2-amino-3-cyano-4-(2-ethoxy-2-oxoethyl)-5-oxo-5,6,7,8-tetrahydro-4H-chromene-4-carboxylate derivatives (4a–f) through a tandem Michael addition–cyclization reaction starting with structurally diverse cyclohexane-1,3-dione, diethyl acetylene dicarboxylate, and malononitrile has been carried out in different organic bases under solvent free condition for the optimization of maximum yield. All the formed 4H-chromenes were characterized by spectral and X-ray methods.