A novel and efficient one-pot method has been developed for the synthesis of cyclopropanes by the cyclization of 4-bromomethylcoumrains, benzaldehydes and active methylene groups in 1:1 acetonitrile and water solvent in the presence of KSCN and K₂CO₃ as a catalyst at room temperature for 2-5 h. The significant attraction of this procedure is environmentally benign, simple procedure, the ready accessibility of the catalyst, excellent yield and mild reaction conditions. The structure of the target molecule (4b) was confirmed by X-ray diffraction.

Synopsis: A library of novel cyclopropanyl coumarin derivatives were synthesised in good yields through one-pot three-component cyclization of 4-bromomethylcoumarins, benzaldehydes and active methylene groups. The structures of the synthesised compounds were confirmed by spectral methods viz. IR, ¹H NMR, ¹³C NMR, mass spectral analysis and X-ray diffraction studies.