Cesium carbonate → tert-butyl 3-{3-[1-(4-amino-3-methyl-1H-pyrazolo[3,4-d]pyrimidin-1-yl)ethyl]-6-cyano-2-methoxy-5-methylphenyl}azetidine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

The tert-butyl 3-[3-(1-chloroethyl)-6-cyano-2-methoxy-5-methylphenyl]azetidine-1-carboxylate (2.3 g, 6.3 mmol) was dissolved in N,N-dimethylformamide (68 mL) with cesium carbonate (4.1 g, 13 mmol) and 3-methyl-1H-pyrazolo[3,4-d]pyrimidin-4-amine (1.4 g, 9.4 mmol) and was heated in an oil bath to 80° C. The reaction was stirred for 18 hrs and allowed to cool to room temperature. The reaction mixture was taken up in ethyl acetate, filtered, washed with water, brine, dried over magnesium sulfate and concentrated to give the crude product. The product was purified by FCC on silica gel eluting a (hexane: 10% ethanol ethyl acetate) gradient to give tert-butyl 3-{3-[-1-(4-amino-3-methyl-1H-pyrazolo[3,4-d]pyrimidin-1-yl)ethyl]-6-cyano-2-methoxy-5-methylphenyl}azetidine-1-carboxylate as a semisolid (1.5 g, 50%). LCMS calculated for C25H32N7O3(M+H)+: m/z=478.2; found: 478.2. The enantiomers were separated by Chiral column HPLC using: Phenomenex LUX Cellulose Column, 21.1×250 mm, 5 micron, 15% ethanol in hexane, 18 mL/min ˜5 mg/injection to give: First peak retention time: 2.1 minutes, tert-butyl 3-{3-[-1-(4-amino-3-methyl-1H-pyrazolo[3,4-d]pyrimidin-1-yl)ethyl]-6-cyano-2-methoxy-5-methylphenyl}azetidine-1-carboxylate; Second peak retention time: 3.9 minutes, tert-butyl 3-{3-[-1-(4-amino-3-methyl-1H-pyrazolo[3,4-d]pyrimidin-1-yl)ethyl]-6-cyano-2-methoxy-5-methylphenyl}azetidine-1-carboxylate.

Provenance & Evidence