MeOH tetrahydrofuran → (+/-)-1-(3-Amino-4-cyano-benzyl)-4-(6-chloro-benzo[b]thiophene-2-sulfonyl)-6-oxo-piperazine-2-carboxylic acid

Participants

Reaction Steps

Water (5 drops) is added to a solution containing (±)-1-(3-amino-4-cyano-benzyl)-4-(6-chloro-benzo[b]thiophene-2-sulfonyl)-6-oxo-piperazine-2-carboxylic acid methyl ester (30 mg, 0.05 mmol), EXAMPLE 99, in a 1:1 mixture of THF/MeOH (2 mL). At ambient temperature, LiOH monohydrate (7 mg, 1.66 mmol) is then added. After 16 h, the reaction mixture is diluted with water and purified by reverse-phase HPLC [Buffer A: water w/0.1% TFA; Buffer B: CH3CN w/0.1% TFA; Gradient: 0% B to 60% B over 30 min] to provide 10 mg (34%) of the title compound as a white solid. 1H NMR (300 MHz, d6-DMSO) δ3.18 (dd, J=12.1, 3.5 Hz, 1H), 3.61 (d, J=16.0 Hz, 1H), 3.77 (d, J=16.0 Hz, 1H), 3.95 (d, J=16.0 Hz, 1H), 4.06 (d, J=12.1 Hz, 1H), 4.14 (m, 1H), 6.40 (d, J=8.0 Hz, 1H), 6.54 (s, 1H), 7.21 (d, J=8.0 Hz, 1H), 7.57 (dd, J=8.6, 1.9 Hz, 1H), 8.06 (d, J=8.6 Hz, 1H), 8.18 (s, 1H), 8.33 (s, 1H) ppm; MS (ISP loop): m/z 505 (M+H).

Provenance & Evidence