Diphosgene → (S)-1-(2-(tert-butyldimethylsilyloxy)ethyl)-4-isopropyl-3-(3-(4-(1-((2-(trimethylsilyl)ethoxy)methyl)-1H-imidazol-2-yl)phenyl)pyrazolo[1,5-a]pyrimidin-5-yl)imidazolidin-2-one

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of (S)—N1-(2-(tert-butyldimethylsilyloxy)ethyl)-3-methyl-N2-(3-(4-(1-((2-(trimethylsilyl)ethoxy)methyl)-1H-imidazol-2-yl)phenyl)pyrazolo[1,5-a]pyrimidin-5-yl)butane-1,2-diamine (0.055 mmol) in dichloromethane (1 mL) was added diisopropylethylamine (0.019 mL, 0.14 mmol). Trichloromethyl chloroformate (0.010 mL, 0.083 mmol) was added dropwise at 0° C. under N2. The reaction mixture was stirred at 0° C. for 30 minutes, then diluted with dichloromethane, washed with aqueous saturated NaHCO3 and brine, dried and concentrated. The residue was purified by silica gel chromatography (dichloromethane:MeOH, 100:1) to give (S)-1-(2-(tert-butyldimethylsilyloxy)ethyl)-4-isopropyl-3-(3-(4-(1-((2-(trimethylsilyl)ethoxy)methyl)-1H-imidazol-2-yl)phenyl)pyrazolo[1,5-a]pyrimidin-5-yl)imidazolidin-2-one (15 mg, 40% for two steps). LCMS (APCI+) m/z 676.9 [M+H]

Provenance & Evidence