Reaction Steps
Prepared from 2-(2-tert-butyldimethylsiloxyethyl)-3,4-dihydro-3-oxo-2H-1,4-benzoxazine by methods F and G, alkylating with 3-(methoxycarbonyl)benzyl chloride, and isolated as a white powder in 87% yield, mp 73°-75° C.; 1H NMR (CDCl3) δ 7.92-7.95 (m, 2H), 7.38-7.43 (m, 2H), 6.96-7.03 (m, 2H), 6.91 (dt, J=2.3, 7.3 Hz, 1H), 6.81 (dd, J=1.4, 7.7 Hz, 1H), 5.23 (d, J=16.3 Hz, 1H), 5.16 (d, J=16.3 Hz, 1H), 4.87 (dd, J=5.7, 7.4 Hz, 1H), 3.92-3.95 (m, 2H), 3.91 (s, 3H), 2.21-2.37 (m, 3H containing one exchangeable hydrogen). 13C NMR (CDCl3) δ 166.9, 166.7, 144.2, 136.5, 130.9 (CH), 130.7, 129.1 (CH), 128.7 (CH), 128.5, 127.7 (CH), 124.3 (CH), 122.9 (CH), 117.4 (CH), 115.4 (CH), 75.3 (CH), 58.9 (CH2), 52.2 (CH2), 45.1 (CH2), 33.3 (CH2). IR 3569, 2948, 1709, 1676, 1502 cm-1. MS 342 (MH+). Anal. Calc'd. for C19H19NO5 : C, 66.85; H, 5.61; N, 4.10. Found: C, 66.37; H, 5.62; N, 3.97.
