Nitrogen → 4-Allyl-5-chloro-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3,4-dihydro-2H-benzo[b][1,4]oxazine

Participants

Reaction Conditions

Reaction Steps

A solution of 5-chloro-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3,4-dihydro-2H-benzo[b][1,4]oxazine (0.504 g, 1.426 mmol, Ref. WO20100130034) and K2CO3 (0.504 g, 3.65 mmol) in dry DMF (5 mL) was sparged with N2 for 5 min, then treated with allyl bromide (0.8 mL, 9.17 mmol). The reaction tube was sealed and then heated (70° C.) for 22 h, then cooled and diluted with water (50 mL) and extracted into EtOAc (50 mL). The organic layer was washed with water, brine, then dried (Na2SO4), filtered, concentrated, and purified by biotage chromatography (4 g SiO2, 0% (3 CV), 0-40% (15 CV), 40% (2 CV); EtOAc in hexanes) to afford the desired product (0.403 g, 1.201 mmol, 84% yield) as a clear viscous oil. 1H NMR (500 MHz, CDCl3) δ 7.30 (d, J=8.2 Hz, 1H), 6.79 (d, J=8.2 Hz, 1H), 6.15-6.02 (m, 1H), 5.31 (dd, J=17.2, 1.4 Hz, 1H), 5.28-5.21 (m, 1H), 4.18-4.13 (m, 2H), 3.59 (d, J=6.0 Hz, 2H), 3.14-3.07 (m, 2H), 1.36 (s, 12H). LCMS (M+H)=336.9.

Provenance & Evidence