Synthesis of a new triheterocycle. Bis-pyrazolo[1,5-a][4',3'-e]pyrimidine

Abstract

Starting from 2,7-dimethyl-8-phenylazo-4(6H)-pyrazolo[1,5-a]-pyrimidinone 1, a series of functionalized derivatives of the title tricyclic system 4 have been synthesized via its reaction with various hydrazonoyl halides 2 and cyclization of the resulting substitution products 3. The mechanism and the site selectivity of the reactions studied are discussed. The structures of the compounds 3 and 4 isolated were elucidated on the basis of their spectra, elemental analyses and alternate synthesis.

New synthetic strategy for novel 6-arylazo-5-methyl-3-aryl-thiazolo[2,3-c]-[1,2,4]triazoles and study of their solvatochromic properties

“…Elemental analyses were carried out by the Microanalytical Center of Cairo University, Giza, Egypt. Both the hydrazonoyl chlorides 1 13 and substituted benzaldehyde thiosemicarbazones 2 were prepared as previously described. 14 * Correspondence: as shawali@mail.com…”