Nitrogen → 4-Allyl-7-fluoro-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 7-fluoro-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-3,4-dihydro-2H-benzo[b][1,4]oxazine (0.503 g, 1.802 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 then heated (70° C.) for 22 h. The reaction was diluted with water (50 mL) and extracted into EtOAc (50 mL). The organic layer was washed with water, brine, and then dried (Na2SO4), filtered, and concentrated. The residue was purified by biotage (4 g SiO2, 5% (3 CV), 5-40% (15 CV), 40% (2 CV), EtOAc in hexanes), affording the desired product (0.430 g, 1.347 mmol, 74.8% yield) as a clear viscous oil. 1H NMR (500 MHz, CDCl3) δ 7.03 (6, J=5.7 Hz, 1H), 6.51 (d, J=9.9 Hz, 1H), 5.84-5.94 (m, 1H), 5.26-5.31 (m, 1H), 5.24 (m, 1H), 4.25-4.32 (m, 2H), 3.87 (m, 2H), 3.19-3.25 (m, 2H), 1.34 (s, 12H). LCMS (M+H)=319.7.

Provenance & Evidence