Reaction Steps
(3R,8S)-3-[4-(3,4-Dichloro-benzyloxy)-phenyl]-2,3,8,9-tetrahydro-6H-[1,4]dioxino[2,3-g]isoquinoline-7,8-dicarboxylic acid 7-tert-butyl ester 8-methyl ester (200 mg) was hydrolyzed according to General Procedure B. The resulting (3R,8S)-3-[4-(3,4-dichloro-benzyloxy)-phenyl]-2,3,8,9-tetrahydro-6H-[1,4]dioxino[2,3-g]isoquinoline-7,8-dicarboxylic acid 7-tert-butyl ester (172 mg) was coupled with (S)-2-amino-3-(4′-cyano-biphenyl-4-yl)-propionic acid methyl ester (126 mg) according to General Procedure A to give (3R,8S)-8-[(S)-2-(4′-cyano-biphenyl-4-yl)-1-methoxycarbonyl-ethylcarbamoyl]-3-[4-(3,4-dichloro-benzyloxy)-phenyl]-2,3,8,9-tetrahydro-6H-[1,4]dioxino[2,3-g]isoquinoline-7-carboxylic acid tert-butyl ester (191 mg). Boc-cyano-biphenyl ester (188 mg) was treated as described in General Procedure C to give (S)-3-(4′-cyano-biphenyl-4-yl)-2-({(3R,8S)-3-[4-(3,4-dichloro-benzyloxy)-phenyl]-2,3,6,7,8,9-hexahydro-[1,4]dioxino[2,3-g]isoquinoline-8-carbonyl}-amino)-propionic acid methyl ester hydrochloride salt (155 mg). LCMS: (m/z) 749; 1H NMR (400 MHz, Methanol-d6): 8.54 (d, 1H), 7.95 (s, 1H), 7.87 (d, 1H), 7.81-7.72 (m, 2H), 7.63-51 (m, 4H), 7.50-7.47 (m, 2H), 7.38-7.32 (m, 3H), 7.01 (d, 2H), 6.99 (d, 2H), 5.07 (s, 2H) 5.04-5.03 (m, 1H), 4.34-4.31 (m, 1H), 4.12-4.08 (m, 1H), 4.01-3.96 (m, 3H), 3.75 (s, 3H), 3.74-3.63 (m, 4H), 3.11-2.97 (m, 2H).
