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Part-IIAim of the Present WorkIn spite of this limitation, the reaction is indeed a facile, high yielding one pot syntheticprocedure for a variety of condensed pyrimidines (Scheme 4).YZZdry HCl gasN+ R NNH 2 N RY= COOR 1 , CONHR 1 , CN, COR 1 etcZZ = OH, NH 2 , chloro, aryl, alkyl, etcScheme-4= benzene, thiophene, furan, pyrrole, imidazole,pyridine, pyrazole, pyridothiophene etc.3.4 Thienopyrimidines as an Important Scaffold for Parallel Synthesis of CompoundLibrary for NDDRReactions that are adaptable for high speed and throughput syntheses have become animportant component of the modern medicinal chemist’s library, as a great number ofcompounds can be produced through such rapid parallel synthetic programs. 46 Syntheticmethods that enable the rapid production of an array of heterocycles, useful for theidentification of new lead structures are of critical importance to the pharmacologicalactivity. Thienopyrimidine and other condensed pyrimidines scaffolds and theirderivatives are important heterocyclic building blocks and have been shown to possesssignificant pharmacological activity against a variety of molecular targets. 47Extensive work on condensed 2-substitutedpyrimidin-4(3H)-ones, 23, especiallythieno[2,3-d]pyrimidin-4(3H)-ones by Shishoo et al., as discussed above involve thereaction of nitriles under acidic conditions using dry HCl gas. 36-44 Thesecondensedpyrimidines have four diversity points.R 2R 1XR 4 NR 3N23X = S, -CH=CH-, N, O, etcR 1 , R 2 = H, alkyl, aryl, cycloalkyl, carboalkoxy, carbocyclic, heterocyclic, etcR 3 = alkyl, aryl, arylalkyl, heteroaryl, substituted amino, heteroalkyl,aryl, etcR 4 = OH, alkyl, aryl, Cl, NH 2315