Synthesis and reactivity of N-[3-amino-4-(benzoxazol-2-yl)pyrazol-5-yl]phenylamine

Abstract

Pyrazolo[5,1- a]pyrimidines and pyrazolo[5,1-c][1,2,4]triazines containing benzooxazole moiety are synthesised from N-[3-amino-4-(benzoxazol-2-yl)pyrazol-5-yl]phenylamine or its diazonium chloride with the appropriate active methylene compounds. The newly synthesised compounds were elucidated by elemental analysis, spectral data and alternative synthetic route whenever possible.

Synthesis and reactions of pyrazolo[5,1-c][1,2,4]triazine-3-carbothioamides

“…7 According to the patent data, 8 certain polysubstituted pyrazolo [5,1-c] [1,2,4]triazines selectively inhibit B-Raf kinase activity and are useful for treating disorders mediated by B-Raf kinase. The most concise approach to the synthesis of pyrazolo[5,1c] [1,2,4]triazine scaffolds is based on the azo-coupling of pyrazole-3(5)-diazonium salts 1 with active methylene/methine compounds followed by the intramolecular cyclization of hydrazone intermediates 2: 1,9,10 A number of 4-aminopyrazolo [5,1-c] [1,2,4]triazines were obtained by reactions of diazonium salts 1 with methylene active nitriles such as malononitrile [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] , 2-(cyanomethyl)thiazoles, 28,29 2-(cyanomethyl)benzoxazole, 19 ethyl cyanoacetate, 11,17,20,21,26,30,31 α-cyanoketones, 30,[32][33][34][35] 2-(cyanomethyl)thiadiazoles,...…”

Convenient synthesis of some new pyrazolo[1,5‐a]pyrimidine, pyridine, thieno[2,3‐b]pyridine, and isoxazolo[3,4‐d]pyridazine derivatives containing benzofuran moiety

“…Our research has been devoted to the development of new classes of heterocyclic systems which incorporate the thienopyrimidine moiety in the hope that they may be biologically active. In continuation of our interest in the synthesis of heterocycles [22][23][24][25][26], we report herein, a convenient method for the synthesis of pyrazolo [1,5-a]pyrimidines, thieno [2,3-b]pyridines, pyrimidino[4 0 ,5 0 :4,5]thieno [2,3-b]pyridine, isoxazolo [3,4-d]pyridazines, and pyridine containing benzofuran moiety as antimicrobial agents.…”