Hydrochloric Acid → HCID 66833024, compound

Participants

Reaction Steps

2-Amino-6-borono-2-[2-(6,7-dimethoxy-3,4-dihydro-1H-isoquinolin-2-yl)ethyl]-hexanoic acid dihydrochloride is prepared in a manner analogous to that set forth in Example 16, except 6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline is used as the amine in step 6. The final step is as follows: a solution of 2-tert-butoxycarbonylamino-2-[2-(6,7-dimethoxy-3,4-dihydro-1H-isoquinolin-2-yl)ethyl]-6-(4,4,5,5-tetramethyl-[1,3,2]-dioxa-borolan-2-yl)-hexanoic acid ethyl ester (108 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 (66 mg); 1H NMR (D2O, 300 MHz) δ 6.75 (s, 1H), 6.66 (s, 1H), 4.39 (d, J=15 Hz, 1H), 4.14 (d, J=15 Hz, 1H), 3.67 (s, 3H), 3.66 (s, 3H), 3.18-3.46 (m, 4H), 2.97 (m, 2H), 2.31 (t, J=8 Hz, 2H), 1.82 (m, 2H), 1.27 (m, 3H), 1.12 (m, 1H) and 0.64 (m, 2H); MS (+CI): m/z for C19H31BN2O6: expected 394.2. found 395.5 (M+H)+, 377.4 (M+H−H2O)+, 359.4 (M+H-2H2O)+.

Provenance & Evidence