A mixture of (2S)-methyl 2-(7-(4-allyl-5-chloro-3,4-dihydro-2H-benzo[b][1,4]oxazin-6-yl)-2-(3-bromophenyl)-5-methylpyrazolo[1,5-a]pyrimidin-6-yl)-2-(tert-butoxy)acetate (120 mg, 0.188 mmol), 3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenol (61.9 mg, 0.281 mmol) and 2M Na2CO3 (0.188 mL, 0.375 mmol) in DMF (2 mL) was degassed for 15 min by bubbling N2 through the reaction mixture. Then, tetrakis(triphenylphosphine)pallafium(0) (15.17 mg, 0.013 mmol) was added and the degassing was continue for another 5 min. The mixture was then heated at 90° C. for 16 h. After cooling to room temperature, water was added and the mixture was extracted with ether (2×50 mL), washed with brine (25 mL), dried (Na2SO4), filtered and concentrated. The residue was then purified by biotage (10-40% EtOAc/hexane) to afford (2S)-methyl 2-(7-(4-allyl-5-chloro-3,4-dihydro-2H-benzo[b][1,4]oxazin-6-yl)-2-(3′-hydroxy-[1,1′-biphenyl]-3-yl)-5-methylpyrazolo[1,5-a]pyrimidin-6-yl)-2-(tert-butoxy)acetate (90 mg, 0.138 mmol, 73.5% yield) as off-white solid. 1H NMR (500 MHz, CDCl3) δ: 8.02 (t, J=1.6 Hz, 1H), 7.82 (dt, J=7.6, 1.4 Hz, 1H), 7.54-7.51 (m, 1H), 7.47-7.43 (m, 1H), 7.33-7.29 (m, 1H), 7.19-7.13 (m, 1H), 7.10 (t, J=8.1 Hz, 1H), 7.02-7.00 (m, 1H), 6.98 (s, 2H), 6.93 (s, 1H), 6.81 (ddd, J=8.0, 2.5, 0.9 Hz, 1H), 6.42 (dd, J=8.1, 2.3 Hz, 2H), 6.39-6.35 (m, 1H), 6.10-5.98 (m, 1H), 5.40-5.30 (m, 2H), 5.07 (s, 1H), 4.29-4.18 (m, 2H), 3.67 (s, 3H), 3.18 (t, J=4.4 Hz, 2H), 2.87 (s, 3H), 1.18 (s, 9H). LCMS (M+H)=653.4.
