Hydrochloric Acid → HCID 86663710, compound

Participants

Reaction Steps

(R)-2-Amino-6-borono-2-[2-piperidin-1-yl)-ethyl]-hexanoic acid dihydrochloride is prepared in a manner analogous to that set forth in Example 1, except piperidinyl is used as the amine in step 7. The final step is as follows: a solution of (R)-2-tert-butoxycarbonylamino-2-(2-piperidin-1-yl-ethyl)-6-(4,4,5,5-tetramethyl-[1,3,2]-dioxa-borolan-2-yl)-hexanoic acid methyl ester (182 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 (R)-2-amino-6-borono-2-[2-piperidin-1-yl)-ethyl]-hexanoic acid dihydrochloride as a colorless foam (72 mg, 53%); 1H NMR (D2O, 300 MHz) δ 3.34 (d, J=11.5 Hz, 2H), 3.14 (m, 1H), 2.97 (m, 1H), 2.77 (t, J=12 Hz, 2H), 2.19 (t, J=8.5 Hz, 2H), 1.76 (m, 4H), 1.55 (m, 3H), 1.23 (m, 4H), 1.06 (m, 1H) and 0.59 (t, J=7.5 Hz, 2H).

Provenance & Evidence