M. Kidwai, P. Sapra, K. Bhushan
Jul 20, 1999
Citations
0
Influential Citations
3
Citations
Journal
ChemInform
Abstract
Fluorination on 2-chloro-3-formylquino lines has been carried out in su lfolane, acetoni tri le and acetamide using potass ium fluoride (KF) and tetramethylammon ium chloride (TMA C) under microwave irradiati on as well as conventional heating . The reaction time has been brought down from hours to minutes with ilJlproved yields using microwave irradiation . The rate of fluorination of 2-chloro-3-formylquinoline is more in acetamide followed by ace tonitril e. As fluorine in organic compounds leads to increase lipid solubility in membranes, because of higher solubility they are biologically active and can be used in the synthesis of drugs 1.2. Recently , the use of microwave irradiation (MWI) in connection with the synthes is of heterocycles, has become a field of interest in our laboratory4-o. Keepi ng in view the substantial reduction in the reaction time with improved yield under MWI, it was thought worthwhile to synthesise new 2-fluoro-3fo rmylquinolines in different solvent systems under MW I usi ng a domestic microwave oven as well as in a conventional way. Fluorination of substituted 2-chloro-3-formylqu inolines la-e in sulfolane, acetonitrile and acetamide usi ng KF and TMAC under MWI and also by conventional heating method furni shed prlJducts 2a-e (cf. Scheme 1). The reaction time has been brought down from hours to minutes with improved yields usi ng mIcrowave ilTadiation . The characteri zation data of the products 2a-e are g iven in Tables I and II. The melting points of a ll the products were more than 300°C therefore could not be mentioned . The observed order of fluorination of 2chloro-3-formylquinoline using KF and TMAC is:acetamide > acetonitrile > sulfolane.