A PRACTICAL GREEN SYNTHESIS OF THIAZINE DERIVATIVES USING PHASE TRANSFER CATALYST

An operationally simple and environmental benign approach for the synthesis of thiazines under catalysis of tetrabutylammonium bromide (TBAB) as phase transfer catalyst (PTC) in the dichloromethane-water biphasic solvent system has been explored . This reaction has generated renewed interest in preparing thiazines.. Mild reaction conditions, enhanced rates, improved efficiency of reaction with maximum atom economy, use of an inexpensive catalyst, green solvent system and reduced reaction time are the salient features of our process. Our protocol extends the benefits to synthesis of 5-(2-amino-6-(3,4-substituted phenyl)-5,6-dihydro-4H-1,3-thiazine-4yl)-6-methyl-4-(substituted tolyl)-3,4-dihydropyrimidine-2(1H)-one derivatives in excellent yield. The structures of all the synthesized compounds have been confirmed by elemental analysis, FT-IR, HNMR, C NMR and mass spectral data.