IMPROVED MICROWAVE-INDUCED SYNTHESES AND REACTIONS OF 2-ARYL-3-(3-ARYL-3-OXO-PROPEN-1-YL)-INDOLES WITH THIOUREA AND HYDRAZINE DERIVATIVES

The potential of domestic microwave oven has been utilized to accelera te the reactions of 2-aryl-3-(3-aryl-3-oxo-propen-1-yl)-indoles (III) with hydrazine hydrate/phenyl hydrazine and thiourea, to obtain 2-aryl -3-[3-aryl-pyrazol-5-yl]-indoles (IV) and 2-aryl-3-[4-aryl-5, 6-dihydr o-2(1H)-thioxopyrimidine-6yl]-indole (V). The former indolyl chalcones (III) have been synthesized by the condensation of 2-aryl-1H-indole-3 -carboxaldehyde (I) and fluorinated acetophenones (II) in the presence of sodium hydroxide in open borosil glass vessels under microwave irr adiation, using ethanol as energy transfer medium. The results obtaine d demonstrate the versatility of the process as considerable reaction rate enhancement has been observed bringing down the reaction time fro m hours to seconds, along with improved yields. All synthesized compou nds have been characterized on the basis of elemental analyses, IR, H- 1 NMR, F-19 NMR and mass spectral studies.