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

Participants

Reaction Conditions

Reaction Steps

Tert-butyl N-[3-(1,3-benzoxazol-2-yl)-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2-pyridyl]-N-tert-butoxycarbonyl-carbamate (237 mg), tert-butyl 4-(4-bromo-3-(hydroxymethyl)-1H-pyrazol-1-yl)piperidine-1-carboxylate (159 mg), potassium phosphate (225 mg) and trisdibenzilideneacetone dipalladium (20.19 mg) and tricyclohexylphosphine (12.37 mg) were weighed out in a microwave vial, sealed and 1,4-dioxane (4 ml) and water (400 μl) were added. Argon was bubbled through the suspension at 25° C. for 5 minutes. The mixture was stirred at 120° C. for 2 hours. The reaction mixture was allowed to cool down, Dicalite Speed Plus (Acros Chemicals) was added and the mixture was concentrated. The crude product was purified by flash chromatography on silica gel eluting with 50 to 100% ethyl acetate in petroleum ether. The solvent was evaporated to dryness to afford tert-butyl 4-[4-[5-(1,3-benzoxazol-2-yl)-6-(bis(tert-butoxycarbonyl)amino)-3-pyridyl]-3-(hydroxymethyl)pyrazol-1-yl]piperidine-1-carboxylate (150 mg). The N-tert-butoxycarbonyl groups on the resultant product were removed by conventional treatment with trifluoroacetic acid to afford [4-[6-amino-5-(1,3-benzoxazol-2-yl)-3-pyridyl]-1-(4-piperidyl)pyrazol-3-yl]methanol (49.0 mg) as a solid.

Provenance & Evidence