5-Amino-3-methyl-1-phenylpyrazole → 6-(4-bromophenyl)-3-methyl-1-phenyl-1H-pyrazolo[3,4-b]pyridin-4(7H)-one

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Into a 250 mL round-bottom flask, was placed a solution of 3-methyl-1-phenyl-1H-pyrazol-5-amine (20 g, 115.61 mmol, 1.00 equiv) in polyphosphoric acid (100 mL), ethyl 3-(4-bromophenyl)-3-oxopropanoate (31.21 g, 115.59 mmol, 1.00 equiv). The resulting solution was stirred overnight at 130° C. in an oil bath, then cooled to room temperature. The resulting solution was diluted with ice water:ethyl acetate (500 mL/500 mL). The resulting solution was extracted with ethyl acetate (5×500 mL), the organic layers combined and dried over anhydrous magnesium sulfate. The solids were filtered out. The resulting mixture was concentrated under vacuum. The resulting residue was applied onto a silica gel column with ethyl acetate/petroleum ether (1:20) to yield 6-(4-bromophenyl)-3-methyl-1-phenyl-1H-pyrazolo[3,4-b]pyridin-4(7H)-one as a white solid. 1HNMR (300 MHz, CDCl3, ppm): δ 1.46-1.48 (3H, m), 6.87 (1H, s), 7.28-8.26 (9H, m).

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