In a 50 ml pear flask was added 2-methyl-7-phenylpyrazolo[1,5-a]pyrimidin-5-amine (10A, 450 mg, 2.0 mmol) in pyridine (10 ml). To this mixture was added 4-(2-cyanopropan-2-yl)benzoyl chloride (550 mg, 2.6 mmol) and the mixture was stirred at room temperature for 2 h. Saturated NaHCO3 was then added and pyridine was removed in vacuo. The residue was partitioned between saturated NaHCO3 and ethyl acetate, and the aqueous layer was extracted one more time with ethyl acetate. Combined organic layers were dried over MgSO4, filtered and concentrated. The crude product was purified by column chromatography (SiO2, 15-25% EtOAc/hexanes) to give the titled compound (380 mg, 48%). 1H NMR (DMSO-d6) δ: 11.35 (s, 1H), 8.10-8.16 (m, 2H), 8.04-8.09 (m, 2H), 7.96 (s, 1H), 7.67-7.73 (m, 2H), 7.60-7.66 (m, 3H), 6.41 (s, 1H), 2.41 (s, 3H), 1.74 (s, 6H); ESI-MS: m/z 396.3 (M+H)+.
