反应详情

To a mechanically stirred solution at −78° C. under N2 of anhydrous DMSO (16.9 mL, 1.08 mol) in CH2Cl2 (750 mL) was added dropwise via addition funnel oxalyl chloride (44.8 mL, 513 mmol) such that temperature was maintained below −65° C. The reaction was stirred 15 minutes, and a solution of N-[4-Hydroxymethyl-2-(2-methylphenyl)benzoyl]methionine methyl ester (110 g, 285 mmol), prepared as in example 1075F, in CH2Cl2 (100 mL) was added dropwise via addition funnel such that temperature was again maintained below −65° C. After one hour, triethylamine (159 mL, 1.14 mol) was added, and the reaction was warmed to ambient temperature over one hour. The reaction was poured into ether (1.5 L) and washed with brine (2×1.5 L). The organic layer was dried with Na2SO4, filtered, and concentrated in vacuo. The residue was purified by flash chromatography on silica gel (30% EtOAC/Hexanes) to give the desired product as a pale yellow solid (66 g, 60%). 1H(300 MHz, CDCl3) δ 11.00 (1H, s), 8.07 (1H, m), 7.97 (1H, dd, J=8, 2 Hz), 7.75 (1H, bs), 7.40-7.20 (4H, bs), 6.01 (1H, m), 4.63 (1H, m), 3.68 (3H, s), 2.20-2.00 (8H, m), 1.87 (1H, m), 1.63 (1H, m). m/e (ESI) 384 (MH−).

1. temperaturewas maintained below −65° C
2. customwas again maintained below −65° C
3. waitAfter one hour
4. washwashed with brine (2×1.5 L)
5. dry with materialThe organic layer was dried with Na2SO4
6. filtrationfiltered
7. concentrationconcentrated in vacuo
8. customThe residue was purified by flash chromatography on silica gel (30% EtOAC/Hexanes)