New developments toward the synthesis of heterocycles and applications in green chemistry. I. A simple and essentially one-pot synthesis of N-aminated heterocycles using phase transfer catalyst (Aliquat-336). II. Synthesis of pharmaceutically important pyrrole derivatives. III. Applications in green chemistry: Surfactant-mediated environmentally friendly cleavage of aromatic esters and trans-esterification under solvent-free neutral conditions .

摘要

This thesis is divided into three separate parts. In first part, the process development of various anti-viral pyrrolo-triazine derivatives from N-aminated heterocycles under phase transfer conditions (Aliquat-336) is described. N-Amination conditions were developed for the synthesis of 1-amino-3-methyl-1H-pyrrole-2,4-dicarboxylic acid diethyl ester. The reaction yield of 5-methyl-4-oxo-3,4-dihydro-pyrrolo[2,1-f][1,2,4]triazine-6-carboxylic acid ethyl ester was improved from 60% to 83% over the two steps. N-Amination reaction under phase transfer catalyst conditions was found to be excellent for electron poor nitrogen fused heterocycles like pyrroles, and indoles.; In second part, a simple and efficient, one step synthesis of pharmaceutically important pyrrole derivatives is described. A one-pot synthesis of pyrrole diesters was achieved by the base catalyzed Michael addition of ethyl isocyanoacetate to an acetylene ester followed by the concomitant cyclization of the resulting vinyl anion and aromatization of the pyrrole ring.; In the third part, an environmentally friendly, one-pot, surfactant-mediated solvent-free cleavage of aryl esters under neutral conditions and subsequent transesterification is described. (Abstract shortened by UMI.)