Butylamine → HCID 57544612, compound

Participants

Reaction Steps

Solid EDC.HCl (518 mg, 3.3 mmol) was added to a solution of (S)-2-(tert-butoxycarbonylamino)-3-cyclohexylpropanoic acid (405 mg, 1.5 mmol), diisopropylethylamine (2.5 mL, 14 mmol), HOBt (130 mg, 1.0 mmol), DMAP (18 mg, 0.15 mmol), butylamine (0.30 mL, 3 mmol), and anhydrous DMF (25 mL). The resulting clear light yellow solution was stirred at rt for 12 h. The solvent was removed (50° C., 150 Torr) and the residue was taken up in ether (100 mL) and washed with satd aq NaHCO3 (3×10 mL). Hexanes (30 mL) was added to the ether extract and this was washed with water (5×5 mL) and brine (3×5 mL), dried (Na2SO4), decanted, stripped and the crude material was purified using 40 g SiO2 with an eluent of hexanes to 30% MeOH in EA. Combining appropriate fractions and removal of solvent gave (S)-tert-butyl 1-(butylamino)-3-cyclohexyl-1-oxopropan-2-ylcarbamate (417 mg, 85%) as a white solid. 1H NMR (CDCl3) δ 0.80-1.80 (m 20H), 1.50 (s, 9H), 3.20 (m, 2H), 4.01 (d, 1H), 5.01 (d, 1H), 6.50 (bs, 1H). MS ESI+ve m/z 321 (M+Na).

Provenance & Evidence