New One Pot and Efficient Four-Components Reaction for Synthesis of 2,3-Dihydrothiophene Carbamate Derivatives

A new series of 2,3-dihydrothiophenes bearing ethyl carbamate moiety (4 a-4 l) was designed and synthesized through a facile synthetic route involving domino ring-opening/recyclization reaction of 1,3-thiazolidinedione. The synthesis was achieved via a novel one-pot four-component reaction of aromatic aldehydes, malononitrile and 1,3-thiazolidinedione, using 4-dimethylaminopyridine as base catalyst under ethanol reflux. The molecular structures of the synthesized compounds were elucidated by usual spectroscopic techniques such as FT-IR, H-1 NMR, C-13 NMR and HRMS methods. X-ray diffraction was used to confirm the structures of compounds 4 d and 4 j. Readily available starting materials, atom-efficient routes employing more mild reaction conditions and environmentally benign are the attracting features of this current protocol.

Automated summary

A series of compounds bearing ethyl carbamate moiety were synthesized via a facile synthetic route. The structures of the synthesized compounds were elucidated using spectroscopic techniques and X-ray diffraction. This synthesis method offers readily available starting materials, milder reaction conditions, and environmental friendliness.