Studies On The Synthesis Of Some Heterocyclic Compounds In Aqueous Media

This thesis consists of two chapters. Chapter 1: Progress of the organic synthesis reactions in aqueous media recently In the past decade, there has been growing recognition that water is an attractive medium for many organic reactions such as the Claisen rearrangement, the aldol condensation, and the benzoin condensation, Michael addition reaction, Nucleophilic Additions, Substitution reaction, Oxidations, Reductions, Radical reaction and Photochemistry exhibit rat enhancements in water. To date, many more organic transformations have been carried out in water. Chapter 2: Synthesis of some heterocycliccompounds in aqueous media First part, an efficient and convenient approach to the synthesis of 2-amino-3-cyano-4-aryl-7,7-dimethyl-5-oxo-4H-5,6,7,8-tetrahydrobenzo-[b]-pyran derivatives using hexadecyltrimethylammonium bromide (HTMAB) as the catalyst (10 mol%) is described. This method provides several advantages such as neutral conditions, high yields and simple work-up procedure. In addition, water was chosen as a green solvent. Second part, a synthesis of 4-aryl-7,7-dimethyl-5-oxo-3,4,5,6,7,8-hexahydrocoumarin from aromatic aldehyde, 5,5-dimethyl-1,3-cyclohexadion and meldrum's acid catalyzed by hexadecyltrimethylammonium bromide in water is described. This method provides several advantages such as mild reaction conditions, simple work-up procedure and environment friendly. Third part, a simple and clean method for producing 6-amino-4-aryl-5-cyano-3--methyl-1-phenyl-1,4-dihydropyrano[2,3-c]pyrazole from aromatic aldehyde, malononitrile and 3-methyl-1-phenyl-2-pyrazolin-5-one catalyzed by hexadecyltrimethylammonium bromide (HTMAB) in water is described. This method provides several advantages such as mild reaction conditions, simple work-up procedure and being environmentally friendly. Fourth part, a synthesis of aryl-bis(3-methyl-1-phenyl-5-pyrazolone-4-yl) methane from aromatic aldehyde and 3-methyl-1-phenyl-5-pyrazolone catalyzed by hexadecyl--trimethylammoniumbromide in water is described. This method provides several advantages...