Triethylamine → HCID 66833261, compound

Participants

Reaction Steps

A stirred solution of crude 2-amino-6-borono-2-(piperidin-4-yl)hexanoic acid dihydrochloride (Example 26-A, Step 1, 0.240 g, 0.594 mmol) in dry DMF (12 mL) under nitrogen was treated with triethylamine (0.662 mL, 4.75 mmol) to give a white slurry. 1-chloro-4-(isocyanatomethyl)benzene (0.177 mL, 1.34 mmol) was added dropwise, and the resulting opaque mixture was stirred at room temperature for 1 h. The mixture was diluted with 1 N HCl (15 mL) and washed with ethyl acetate (2×20 mL), and the aqueous layer was concentrated under reduced pressure to give the crude product which was purified by reverse phase HPLC [Phenomenex Luna 250×30.00 mm, 10 micron column. 40 mL/min flow rate. Gradient: solvent A is 0.07% TFA in acetonitrile; solvent B is 0.10% TFA in water; 5% to 50% A over 24 min, then 50% to 100% A over 1 min]. Product fractions were pooled and concentrated, and the residue was taken up in 0.5N HCl (5 mL)/acetonitrile (8 mL) and concentrated. The residue was once again treated with 0.5N HCl (5 mL)/acetonitrile (8 mL) and concentrated and dried under high vacuum overnight to give 2-amino-6-borono-2-{1-[(4-chlorobenzyl)carbamoyl]-piperidin-4-yl}hexanoic acid hydrochloride (92 mg, 34%) as an off-white solid. 1H NMR (D2O, 400 MHz) δ 7.26 (m, 2H), 7.15 (m, 2H), 4.19 (s, 2H), 3.95 (bt, J=14.6 Hz, 2H), 2.75 (bt, J=12.8 Hz, 2H), 2.06 (bt, J=12.4 Hz, 1H), 1.81 (m, 3H), 1.53 (bd, J=12.8 Hz, 1H), 1.32 (m, 4H), 1.11 (m, 2H), 0.69 (t, J=7.6 Hz, 2H). ESI+ MS found for C19H29BClN3O5 m/z 408.4 (M−18+H); ESI− MS m/z 424.4 (M−H), 406.4 (M−18−H).

Provenance & Evidence