Study On The Cleaning And Synthesis Of Chalcone Derivatives Of Drug Intermediates

Over the past few decades, chemists have focused their research interest on aldol condensation owing to its directness, clean procedures and the accessible starting materials. a, β-unsaturated ketones are both important intermediates in synthetic organic chemistry, but also the basic structural unit of many pharmaceutical compounds. Hence, the investigations on a, β-unsaturated ketones with aldol condensation would be a valuable and interesting subject. In this dissertation, we wish to report the studies on aldol condensation reaction under two different conditions. The results are as follows:1. Using Ca(OH)2 catalyst, a series of chalcones were synthesised by aldol condensation and the following dehydration in dilute aqueous ethanol, including the symmetrically or asymmetrically substituted dimethylidene acetone derivatives; further more, we used the one-pot method to synthesize asymmetrically substituted dimethylidene acetone derivatives. Compared with traditional methods, the starting materials are accessible; the conditions are mild; and the reaction is easy to operate. An advanced method for the preparation of symmetrically or asymmetrically substituted dimethylidene acetone derivatives was then developed.35 analogues were synthesized and characterized by NMR, IR, GC-MS spectra.2. Using L-proline catalyst and secondary amines as co-catalyst, the useful building blocks 2-methylenecyclobutanones (2-MCBones) were synthesized through the condensation of cyclobutanone with alderhydes. Compared with the literature, the conditions are mild and it employs near neutral catalysts, which are stable to the acidic impurities in substrates. It is more suitable for industrial production. The 10 compounds were identified by NMR, IR, GC-MS spectra.