Chloroform → (1R)-(4-(1-(1-cyclopentyl-3-oxopropyl)-1H-pyrazol-4-yl)-7H-pyrrolo[2,3-d]pyrimidin-7-yl)methyl pivalate

Participants

Reaction Steps

A solution of (2E)-3-cyclopentylacrylaldehyde (28, 345 mg, 2.50 mmol, 5.0 equiv), (2R)-2-bis[3,5-bis(trifluoromethyl)phenyl][(triethylsilyl)oxy]methylpyrrolidine ((R)-35, 16 mg, 0.025 mmol, 0.05 equiv) and 4-nitrobenzoic acid (4.3 mg, 0.025 mmol, 0.05 equiv) in anhydrous chloroform (CHCl3, 2.0 mL, 25 mmol) was stirred at room temperature for 10 min before [4-(1H-pyrazol-4-yl)-7H-pyrrolo[2,3-d]pyrimidin-7-yl]methyl pivalate (5, 0.150 g, 0.50 mmol) was added. The resulting reaction mixture was stirred at room temperature for 23 h. After LCMS showed that the reaction was deemed complete, the reaction mixture was concentrated under reduced pressure. The residue was directly purified by Combiflash with 0-80% EtOAc/hexane gradient elution to afford (1R)-(4-(1-(1-cyclopentyl-3-oxopropyl)-1H-pyrazol-4-yl)-7H-pyrrolo[2,3-d]pyrimidin-7-yl)methyl pivalate ((R)-37, 169 mg, 211.8 mg theoretical, 80% yield) as a pale yellow foam. For (R)-37: C23H29N5O3 (MW, 423.51), LCMS (EI) m/e 424 (M++H).

Provenance & Evidence