Potassium Phosphate, Tribasic → Tert-butyl 4-[4-[6-amino-5-(1,3-benzoxazol-2-yl)-3-pyridyl]-3-methyl-pyrazol-1-yl]piperidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

A mixture of 3-(1,3-benzoxazol-2-yl)-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridin-2-amine (600 mg), tert-butyl 4-(4-bromo-3-methyl-pyrazol-1-yl)piperidine-1-carboxylate (557 mg), tris(dibenzylideneacetone)dipalladium (74.1 mg), tricyclohexylphosphine (45.4 mg) and potassium phosphate (584 mg) in 1,4-dioxane (3.4 mL) and water (0.4 mL) was degassed with argon, then stirred at 100° C. for 3 h under argon. Solvents were removed. The crude product was adsorbed on silica gel and purified by flash chromatography on silica gel eluting with 5 to 10% methanol in dichloromethane. The solvent was evaporated to dryness to afford tert-butyl 4-[4-[6-amino-5-(1,3-benzoxazol-2-yl)-3-pyridyl]-3-methyl-pyrazol-1-yl]piperidine-1-carboxylate (500 mg); NMR Spectrum: (DMSOd6) 1.43 (s, 9H), 1.78 (dd, 1H), 1.83 (dd, 1H), 1.99-2.07 (m, 2H), 2.33 (s, 3H), 2.91 (bs, 2H), 4.01-4.11 (m, 2H), 4.24-4.32 (m, 1H), 7.42-7.50 (m, 2H), 7.65 (bs, 2H), 7.77-7.83 (m, 2H), 8.10 (s, 1H), 8.29 (d, 1H), 8.35 (d, 1H); Mass spectrum: M+H+: 475

Provenance & Evidence