Hydrochloric Acid → HCID 66833518, compound

Participants

Reaction Steps

(2-Amino-6-borono-2-[2-(4-hyrdoxymethylpiperidin-1-yl)-ethyl]-hexanoic acid dihydrochloride is prepared in a manner analogous to that set forth in Example 16, except piperidin-4-ylmethanol is used as the amine in step 6. The final step is as follows: a solution of (R)-2-tert-butoxycarbonylamino-2-[2-(4-hydroxymethyl-piperidin-1-yl)-ethyl]-6-(4,4,5,5-tetramethyl-[1,3,2]-dioxa-borolan-2-yl)-hexanoic acid ethyl ester (78 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 the title compound as a colorless foam (20 mg, 53%); 1H NMR (D2O, 300 MHz) δ 3.48 (m, 2H), 3.33 (d, J=6 Hz, 2H), 3.21 (m, 1H), 3.04 (m, 1H), 2.86 (m, 2H), 2.19 (2H, t, J=8.5 Hz), 1.86 (m, 2H), 1.60-1.78 (m, 3H), 1.20-1.36 (m, 5H), 1.09 (m, 1H) and 0.64 (t, J=7.5 Hz, 2H,); MS (+CI): m/z for C12H25BN2O4: expected 272.2. found 273.2 (M+H)+.

Provenance & Evidence