2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → HCID 86635964, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of tert-butyl (2S,4R)-4-(benzyloxy)-2-((R)-{[2-chloro-3-(trifluoromethyl)benzoyl]amino}{4-[(cyclopropylmethyl)sulfonyl]phenyl}methyl)-pyrrolidine-1-carboxylate (330 mg, 0.49 mmol) prepared from (2S,4R)-4-(benzyloxy)-1-(tert-butoxycarbonyl)pyrrolidine-2-carboxylic acid using the method outlined for Examples 11-46, DDQ (0.78 g, 3.4 mmol), DCE (25 mL) and water (1.5 mL) was stirred at 60° C. for 10 hours. After cooling to rt, 1,4-cyclohexadiene (0.76 ml) was added. The mixture was stirred for 5 min. and diluted with ether (70 ml). The mixture was washed with sat. aq. NaHCO3. The organic extract was dried and concentrated. The residue purified by preparative TLC (DCM:MeOH 10%) to give the title product (150 mg, 50%). 1H NMR (CDCl3) δ (ppm) 9.77 (1H, d, J=5.9 Hz), 7.92 (2H, d, J=8.2 Hz), 7.76 (1H, d, J=7.5 Hz), 7.65 (1H, d, J=6.8 Hz), 7.54 (2H, t, J=8.0 Hz), 7.43 (1H, t, J=7.6 Hz), 5.12 (1H, d, J=6.4 Hz), 4.56 (1H, t, J=7.9 Hz), 3.92 (1H, br s), 3.40 (1H, d, J=12.2 Hz), 3.07-2.97 (2H, m), 2.52 (1H, dd, J=8.6 and 3.8 Hz), 2.32-2.22 (1H, m), 1.93-1.87 (1H, m), 1.49 (9H, s), 1.01 (1H, m), 0.57 (2H, m), 0.14 (2H, m).

Provenance & Evidence