Ethylene Oxide → tert-butyl N-[2-(2-hydroxyethyl)-3-methoxyphenyl]carbamate

Participants

Reaction Conditions

Reaction Steps

A stirred solution of N-tert-butoxycarbonyl-anisidine (431 g, 1.93 mol) in ether (2 L) under an argon atmosphere was cooled to −20° C. A solution of tert-butyllithium (1.7 M, hexanes, 2.5 L, 4.25 mol) was added dropwise and the reaction was stirred for 3 h at −20° C. The reaction was cooled to −50° C. and ethylene oxide (136 g, 3.09 mol) was added dropwise. The reaction was warmed to 0° C. over 1 h and then stirred at room temperature for 1 h. The reaction was poured onto saturated aqueous ammonium chloride solution (2.5 L) and the mixture was extracted with ether (3×2.5 L). The organic extracts were combined and concentrated in vacuo to afford a pale yellow oil which was purified by column chromatography [SiO2; heptane-ethyl acetate (5:1)] to afford the title compound (176 g, 37%) as a yellow crystalline solid; NMR (400 MHz, CDCl3) δH 1.51 (9H, br s), 2.91 (2H, t, J 6.0 Hz), 3.79 (3H, s), 3.87 (2H, q, J 5.0 Hz, 10.5 Hz), 6.64 (1H, d, J 8.0 Hz), 7.18 (1H, t, J 9.0 Hz), 7.38 (1H, m), 7.55 (1H, br s); IR νmax (Nujol)/cm−1 3407, 3212, 2955, 2854, 1721, 1592, 1508, 1476, 1438, 1370, 1267, 1234, 1162, 1047 and 773.

Provenance & Evidence