Toluene → (3R)-3-cyclopentyl-3-[4-(7-[2-(trimethylsilyl)ethoxy]methyl-7H-pyrrolo[2,3-d]pyrimidin-4-yl)-1H-pyrazol-1-yl]propanal

Participants

Reaction Steps

A solution of (2E)-3-cyclopentylacrylaldehyde (28, 327 mg, 2.50 mmol, 5.0 equiv), (2R)-2-bis[3,5-bis(trifluoromethyl)phenyl][(triethylsilyl)oxy]methylpyrrolidine ((R)-35, 32 mg, 0.050 mmol, 0.10 equiv) and 4-nitrobenzoic acid (8.5 mg, 0.050 mmol, 0.10 equiv) in anhydrous toluene (5.0 mL, 47 mmol) was stirred at room temperature for 10 min before 4-(1H-pyrazol-4-yl)-7-[2-(trimethylsilyl)ethoxy]methyl-7H-pyrrolo[2,3-d]pyrimidine (17, 158 mg, 0.50 mmol) was added. The resulting reaction mixture was stirred at room temperature for 24 h. When LCMS showed that the reaction was deemed complete, the reaction mixture was concentrated under reduced pressure. The residue was directly purified by Combiflash (SiO2) with 0-70% EtOAc/hexane gradient elution to give (3R)-3-cyclopentyl-3-[4-(7-[2-(trimethylsilyl)ethoxy]methyl-7H-pyrrolo[2,3-d]pyrimidin-4-yl)-1H-pyrazol-1-yl]propanal ((R)-38, 184.1 mg, 219.8 mg theoretical, 83.8% yield) as a pale yellow viscous oil. For (R)-38: C23H33N5O2Si (MW, 439.63), LCMS (EI) m/e 440 (M++H).

Provenance & Evidence