1,8-Diazabicyclo(5.4.0)undec-7-ene → tert-Butyl 3-(cyanomethyl)-3-(4-(7-((2-(trimethylsilyl)ethoxy)methyl)-7H-pyrrolo[2,3-d]pyrimidin-4-yl)-1H-pyrazol-1-yl)azetidine-1-carboxylate

Participants

Reaction Steps

A 2 L round bottom flask fitted with overhead stirring, septa and nitrogen inlet was charged with tert-butyl 3-(cyanomethylene)azetidine-1-carboxylate (9.17 g, 0.0472 mol), 4-(1H-pyrazol-4-yl)-7-{[2-(trimethylsilyl)ethoxy]methyl}-7H-pyrrolo[2,3-d]pyrimidine (14.9 g, 0.0472 mol) and acetonitrile (300 mL). The resulting solution was heterogeneous. To the solution was added 1,8-diazabicyclo[5.4.0]undec-7-ene (8.48 mL, 0.0567 mol) portionwise via syringe over 3 min at room temperature. The solution slowly became homogeneous and yellow in color. The reaction was allowed to stir at room temperature for 3 h. The reaction was complete by HPLC and LC/MS and was concentrated by rotary evaporation to remove acetonitrile (˜150 mL). EtOAc (100 mL) was added followed by 100 ml of 20% brine. The two phases were partitioned. The aqueous phase was extracted with 150 mL of EtOAC. The combine organic phases were dried over MgSO4, filtered and concentrated to yield an orange oil. Purification by flash chromatography (150 grams silica, 60% EtOAc/hexanes, loaded with CH2Cl2) yielded the title compound tert-butyl 3-(cyanomethyl)-3-[4-(7-{[2-(trimethylsilyl)ethoxy]methyl}-7H-pyrrolo[2,3-d]pyrimidin-4-yl)-1H-pyrazol-1-yl]azetidine-1-carboxylate as a yellow oil (21.1 g, 88% yield). LC-MS: [M+H]+=510.3.

Provenance & Evidence