Diisopropylethylamine → 2-[5-(1-Benzyl-1H-pyrazol-4-ylcarbamoyl)-2-oxo-1-(2-trimethylsilanyl-ethoxymethyl)-1,2-dihydro-pyridin-3-yl]-indole-1-carboxylic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

Intermediate (1c), 2-[5-carboxy-2-oxo-1-(2-trimethylsilanyl-ethoxymethyl)-1,2-dihydro-pyridin-3-yl]-indole-1-carboxylic acid tert-butyl ester (300 mg, 0.62 mmol), N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (357 mg, 1.86 mmol), 1-hydroxybenzotriazole hydrate (251 mg, 1.86 mmol), N,N-diisopropylethylamine (320 mg, 0.431 mL, 2.48 mmol), 1-benzyl-1H-pyrazol-4-ylamine (322 mg, 1.86 mmol) and tetrahydrofuran (12 mL) were combined in a 20 mL microwave vial. The contents of the vial were heated at 90° C. for 30 minutes under microwave irradiation. The reaction mixture was concentrated in vacuo. The residue was partitioned between water and dichloromethane, and the organic layer was separated. The aqueous was extracted with a further portion of dichloromethane and the combined dichloromethane layers were dried (Na2SO4) and concentrated in vacuo. The resultant crude product was purified by flash chromatography on SiO2 eluting with 20% ethyl acetate/hexane and then 2% methanol/dichloromethane to afford the desired title compound as a solid, 315 mg, 80%.

Provenance & Evidence