Triethylamine → (S)-2-(tert-butoxycarbonylamino)-3-cyclohexylpropyl methanesulfonate

Participants

Reaction Conditions

Reaction Steps

A solution of (S)—N-Boc-2-amino-3-cyclohexylpropanol (20 g, 0.078 mol) in CH2Cl2 (400 mL) and triethylamine (19.6 g, 0.195 mol) was cooled to −20° C. Methanesulfonyl chloride (19.5 g, 0.171 mol) was added with fast dropwise addition maintaining the internal temperature at −20° C. The reaction mixture was stirred at −20° C. for an additional 30 min then for 1 h at 0° C. and then quenched with ice-cold water (200 mL). The mixture was extracted with CH2Cl2 (3×100 mL), washed with water (3×50 mL), dried over Na2SO4, concentrated to give the crude (S)-2-(tert-butoxycarbonylamino)-3-cyclohexylpropyl methanesulfonate (23.3 g, 90%), which was used for the next reaction without further purification. 1H NMR (400 MHz, CDCl3): 4.93 (m, 1H), 4.60 (d, J=7.6 Hz, 1H), 3.67 (m, 2H), 3.12 (s, 3H), 1.87-1.50 (m, 5H), 1.45 (s, 9H), 1.40-0.72 (m, 8H), MS (E/Z): 336 (M+H+).

Provenance & Evidence