Reaction Steps
A solution of (2S)-methyl 2-(7-(4-allyl-5-chloro-3,4-dihydro-2H-benzo[b][1,4]oxazin-6-yl)-2-(2′-hydroxy-[1,1′-biphenyl]-3-yl)-5-methylpyrazolo[1,5-a]pyrimidin-6-yl)-2-(tert-butoxy)acetate (0.058 g, 0.089 mmol) and K2CO3 (0.042 g, 0.304 mmol) in dry acetone (5 mL) was treated with 5-bromopent-1-ene (0.026 g, 0.174 mmol), and the reaction was stirred with heating (70° C. oil bath) for 16 h. The reaction was cooled, then concentrated under reduced pressure. The residue was taken up in CH2Cl2 (5 mL) and washed with 1N HCl (5 mL), dried (Na2SO4), filtered, and concentrated under reduced pressure. The residue was purified by biotage column chromatography (5%-50% EtOAc in hexanes). Product fractions were pooled and concentrated under reduced pressure. The product, (2S)-methyl 2-(7-(4-allyl-5-chloro-3,4-dihydro-2H-benzo[b][1,4]oxazin-6-yl)-5-methyl-2-(2′-(pent-4-en-1-yloxy)-[1,1′-biphenyl]-3-yl)pyrazolo[1,5-a]pyrimidin-6-yl)-2-(tert-butoxy)acetate (0.031 g, 0.040 mmol, 45.4% yield) was isolated as a clear film. 1H NMR (400 MHz, CDCl3) δ 8.04-7.99 (m, 1H), 7.85-7.79 (m, 1H), 7.54-7.49 (m, 1H), 7.44-7.38 (m, 1H), 7.36 (dd, J=7.5, 1.8 Hz, 1H), 7.31 (td, J=7.8, 1.6 Hz, 1H), 7.03 (td, J=7.5, 0.9 Hz, 1H), 7.01-6.94 (m, 3H), 6.90 (s, 1H), 6.03 (ddt, J=16.9, 10.5, 6.0 Hz, 1H), 5.74 (ddt, J=17.0, 10.3, 6.7 Hz, 1H), 5.33 (dd, J=17.1, 1.5 Hz, 1H), 5.24 (d, J=10.0 Hz, 1H), 5.05 (s, 1H), 4.96-4.86 (m, 2H), 4.26 (t, J=4.4 Hz, 2H), 3.96 (t, J=6.4 Hz, 2H), 3.78-3.69 (m, 1H), 3.65 (s, 3H), 3.64-3.55 (m, 1H), 3.20 (q, J=4.2 Hz, 2H), 2.84 (s, 3H), 2.11 (q, J=6.9 Hz, 2H), 1.83-1.71 (m, 2H), 1.63 (s, 1H), 1.17 (s, 9H). LCMS (M+H)=721.5.
