Salicylic acid as a naturally green Brønsted acid catalyst for eco-friendly and simple synthesis of polysubstituted dihydro-2-oxypyrroles under ambient temperature

An efficient and environmental friendly methodology for the synthesis of polysubstituted dihydro-2-oxypyrroles via a one-pot four-component domino condensation of dialkyl acetylenedicarboxylate, formaldehyde and amines (aromatic and aliphatic) at present of salicylic acid as an economical and naturally green Brønsted acid catalyst under ambient temperature with excellent yields and short reaction times is described. Green, natural, inexpensive and non-toxic catalyst, easily separated with no column chromatographic separation and highly efficient is an option for the simple synthesis of these rings.