19949-04-3Relevant academic research and scientific papers
Synthesis of New Condensed Pyrimidine Systems: Reactions of Heterocyclic Amines with Acetylenic Esters
Sahu, J. K.,Dehuri, S. N.,Naik, S.,Nayak, A.
, p. 117 - 120 (2007/10/02)
Several hitherto unreported 1,3,4-oxa/thiadiazolopyrimidin-7-ones (1 and 2) and thiazolopyrimidin-7-ones (3) have been synthesised by the reaction of 2-amino-1,3,4-oxa/thiadiazoles and 2-amino-4-arylthiazoles respectively with ethyl phenylpropiolate.The reaction of these amines with diethyl acetylenedicarboxylate furnishes the 7-oxo-5-carbethoxy derivatives (8-10).A similar reaction of 2-aminobenzothiazole with diethyl acetylenedicarboxylate affords 4-carbethoxypyrimidobenzothiazol-2(H)-one (7).To assign the structures of the 7-oxo derivatives the isomeric 5-oxo-7-carbethoxy derivatives (14) have also been synthesised by an unambiguous route.
Studies on Heterocyclic Compounds. Part VI: Synthesis of Bridgehead Nitrogen Triazine and Pyrimidine Heterocycles
Dehuri, S. N.,Pradhan, P. C.,Nayak, A.
, p. 475 - 478 (2007/10/02)
New bridgehead nitrogen containing heterocycles such as thiazolotriazine (IVa and IVb), imidazolotriazine (IVc), triazinotriazine (IVd and IVe) and oxadiazolotriazine (IVf) and several of their derivatives (V) have been prepared by reacting their respective hydrazine (II) with ethylpyruvate and phenyl glycoxalic acid.The diazotization of hydrazine (II) furnished the reactive intermediates (VI) (azido form) and (VII) (tetrazole form) depending on the structure of hydrazines.These intermediates have been used to synthesise bridgehead nitrogen pyrimidine derivatives (VIII) by reacting them with diethyl fumarate.The spectral and chemical evidences show that diazotised products obtained from 2-hydrazino-4-phenyl thiazole (IIa) and 2-hydrazino benzothiazole (IIb) exist in tetrazole form (VIIa) and (VIIb), respectively, whereas the remaining four (IIa-IIf) remain in the azido form (VIc-VIf) in the solid state.
