Hydrochloric Acid → HCID 66832924, compound

Participants

Reaction Steps

2-Amino-6-borono-2-[2-(3-diethylcarbamoyl-piperidin-1-yl)-ethyl]-hexanoic acid dihydrochloride is prepared in a manner analogous to that set forth in Example 16, except N,N-diethylpiperidine-3-carboxamide is used as the amine in step 6. The final step is as follows: a solution of (2R/S, 3″R/S)-2-tert-butoxycarbonylamino-2-[2-(3-diethylcarbamoyl-piperidin-1-yl)-ethyl]-6-(4,4,5,5-tetramethyl-[1,3,2]-dioxa-borolan-2-yl)-hexanoic acid ethyl ester (128 mg) in 6 N hydrochloric acid (5 mL) was stirred at 95° C. overnight. After cooling to room temperature, the reaction mixture was transferred to a separatory funnel, diluted with deionized water (5 mL) and washed with dichloromethane (3×). The aqueous layer was frozen in liquid nitrogen and lyophilized to give a diastereomeric mixture of the title compounds as a colorless foam (54 mg); 1H NMR (D2O, 300 MHz) δ 3.46 (m, 2H), 3.26 (m, 4H), 3.10 (m, 2H), 2.94 (m, 4H), 2.20 (m, 2H), 1.62-1.92 (6H, m), 1.28 (m, 2H), 1.10 (t, J=7.0 Hz, 3H), 1.06 (m, 1H), 0.93 (t, J=7.0 Hz, 3H) and 0.64 (t, J=7.5 Hz, 2H); MS (+CI): m/z for C18H36BN3O5: expected 385.3. found 386.2 (M+H)+, 368.2 (M+H−H2O)+.

Provenance & Evidence