Abstract
A novel one-pot diastereoselective synthesis of trans-6-aryl-5-hydroxy-2,3-dihydro[2,3-c]pyrazol-4(1H)-ones 3a, 3b, 3c, 3d, 3e, 3f, 3g, 3h is described via the Darzens condensation reaction of 2-chloro-1-(5-hydroxy-3-methyl-1-phenyl-1H-pyrazol-4-yl)ethanone (2) with different aromatic aldehydes in aqueous basic medium. The structures of the compounds prepared were determined by analytical and spectral analyses.