1H-Pyrazol-3-amine, 5-methyl- → tert-butyl 4-[4-[5-cyano-3-methyl-6-(2,3,6-trifluorophenyl)-2,4-dihydro-1H-pyrazolo[3,4-b]pyridin-4-yl]phenyl]piperazine-1-carboxylate

Participants

Reaction Steps

To 1.1 g (5.52 mmol) of 3-oxo-3-(2,3,6-trifluorophenyl)propanenitrile diluted in 20 ml of acetonitrile are respectively added 1.60 g (5.52 mmol) of tert-butyl 4-(4-formylphenyl)piperazine-1-carboxylate and 0.53 g (5.52 mmol) of 3-amino-5-methyl-pyrazole. The reaction mixture is refluxed for 4 h then the solvent is concentrated. The residue is purified by chromatography on silica (cyclohexane/ethyl acetate eluent: 5:5) then the solid obtained is triturated in ethyl acetate and dried to yield 2.48 g (81%) of tert-butyl 4-(4-(5-cyano-3-methyl-6-(2,3,6-trifluorophenyl)-4,7-dihydro-1H-pyrazolo[3,4-b]pyridin-4-yl)phenyl)piperazine-1-carboxylate in the form of a yellow solid.

Provenance & Evidence