Download (4Mb) - Etheses - Saurashtra University

Part-IISynthesis of Pyrimidinesamidine hydrohalide or its hydrohalide adduct. Assuming that the imidoyl halidederivatives is the common intermediate, the formation of 4-aminopyrimidines, III cantake place by ‘path a’ from the cyclic adduct and that of the 4-halopyrimidines IV by the‘path b’ or ‘path c’ (Scheme 9).NNdry HX+ RCNRNH 232NNH 2. HXNH 2. HXXdry HXXNHNIIINPath a-HXRNNHNH 2. HXR32aNPath cRNH 2. HXXNH 2. HXXNHNRN32bRNH32cNH 2. HXPath b-NH 4 X-NH 4 XXXNNNRNRIVIVX = Cl, BrScheme 91.6 Synthesis of Various Mononuclear Pyrimidines under Influence of Dry HCl GasThis novel reaction has been extended to the synthesis of monocyclic pyrimidines. Thus,ethyl cyanoacetate has been condensed with monoaryl and diaryl thioureas 35 to yield 6-amino-1-aryl and 6-amino-1, 3-diaryl thiouracils. 65,66259