Download (3100Kb) - Etheses - Saurashtra University

(b) By the condensation of malonic ester and urea led to formation ofpyrimidine. 165(c) By the condensation of formamidine with phenylazomalononitrile led toformation of 4,5,6 – triaminopyrimidine. 166(d) By the condensation of aromatic aldehydes, ß-ketoester or substituted ß-ketoester with urea or thiourea led to formation of pyrimidines. 167(e) By the condensation of thiourea and substituted ß-ketoester in presence ofsodium ethoxid e led to formation of 2-mercaptopyrimidines. 168(f) By the condensation of chalcones with dicyandiamide in presence ofpiperidine led to formation of pyrimidines. 169(g) By thermal or microwave irridiation of thiourea and substituted ß -ketoesterin presence of dimethylformamide led to formation of substitutedtetrahydropyrimidines. 170(h) One pot synthesis of substituted dihydropyrimidin-2-ones catalysed by171CuCl 2.(i) Synthesis of 3,4-dihydropyrimidin- 2- (1H)- ones/thiones under micro waveirradiation. 172(j) One pot efficient and novel synthesis of dihydropyrimidin-2-(1H)-onescatalysed by Tin (II) chloride (SnCl 2 ). 173(k) By microwave induced eco-friendly solvent free Biginelli reaction catalysed bycalcium chloride. 174Pyrimidines have found their applications as herbicidal 175 and pesticidal 176-177 agents. Yoshida et al. 178 have synthesized 4-amino-5-formyl-2-mercaptopyrimidines as agrochemical intermediates. C. Srivastava et al. 179 havesynthesized new substituted pyrimidines (3) as potential insecticides. N. Yasushi etal. 180 synthesized 6-(1-fluoroethyl)-5-iodo-4-alkylamino Pyrimidines(4) aspesticides for agriculture and horticulture. Besides such a great biologicalimportance of pyrimidines they also contribute to an important44Pyrimidine…..