106915-96-2Relevant academic research and scientific papers
Reaction of Pyrazolopyrimidinethiones with Hydrazine: Synthesis of Novel Substituted Pyrazolopyrimidine and Pyrazolotetrazolopyrimidine Derivatives
Marei, Mohamed Gaber,El-Ghanam, Moneim
, p. 2175 - 2188 (2007/10/02)
5-Aryl-7-hydrazino-2-phenylpyrazolopyrimidines have been synthesised in excellent yields by the reaction of 5-aryl-2-phenylpyrazolopyrimidine-7(6H)-thiones with hydrazine hydrate in refluxing ethanol.The 7-hydrazino derivatives promoted dehydrazination as well as halogenation leading to the formation of the respective 3-halo-pyrazolopyrimidinones on reaction with bromine or iodine monochloride.Their nitration gave a mixture of 3-nitro-7-one and 7-azido-3-nitro derivatives.With nitrous acid, the corresponding 7-azido-pyrazolopyrimidines and pyrazolotetrazolopyrimidines were formed.The latter hitherto unknown tricyclic compounds can also be obtained on prolonged heating of the respective 7-azido derivatives in ethanol.This reaction furnishes a new method of synthesis of a new class of pyrazolo-tetrazolopyrimidines.The structure of the above compounds were confirmed from their spectral characteristics
A New Synthesis of Pyrazolopyrimidines from Acetylenic β-Diketones
Marei, Mohamed Gaber,Aly, Dalia Mahmoud,Mishrikey, Morcos Michael
, p. 3419 - 3422 (2007/10/02)
2-Aryl-2-phenylpyrazolopyrimidine-7(6H)-thiones have been synthesized by the reaction of 1,5-diaryl-4-pentyne-1,3-diones with thiosemicarbazide and their reactions were studied.The pyrazolopyrimidinethiones give with certain electrophiles the respective 3-substituted 7-thiones.Their oxidation affords the corresponding disulfide.Moreover, they can be converted to the corresponding pyrazolopyrimidinones on reaction with alkaline hydrogen peroxide.The structure of the above compounds was confirmed from their spectral characteristics.
REACTIONS OF HETEROCYCLIC CATIONS WITH N-CONTAINING NUCLEOPHILES. 15. REACTION OF 2,6-DIPHENYLPYRYLIUM PERCHLORATE WITH SEMI- AND THIOSEMICARBAZIDES
Zvezdina, E. A.,Zhdanova, M. P.,Anisimova, O. S.,Nechayuk, I. I.
, p. 1322 - 1326 (2007/10/02)
The reaction of 2,6-diphenylpyrylium perchlorate with semi- and thiosemicarbazides in ethanol leads to 1-carbamoyl- and 1-thiocarbamoyl-3-phenyl-5-phenacyl-4,5-dihydropyrazoles, the cyclization of which yields 2,5-diphenyl-7-oxo(thio)-pyrazolopyrimidines.The tautomeric form of the latter is established by comparing their electronic absorption spectra with the spectra of the methyl derivatives.
