反应详情

A solution of N-(2-acetyl-4-chlorophenyl)trifluoromethanesulfonamide 19 (150 mg, 0.50 mmol), O-(2,4-bistrifluoromethylbenzyl)hydroxylamine hydrochloride (154 mg, 0.52 mmol) and anhydrous NaOAc (43 mg, 0.52 mmol) in EtOH (20 mL) was stirred for 15 h at RT. The reaction mixture was concentrated under vacuum and the residue filtered through a pad of silica (eluting with CH2Cl2/PE, 7:3). Purification by radial thin layer chromatography (eluting with CH2Cl2/PE, 7.5:92.5 to 1:9) afforded a pale yellow solid which was recrystallized from CH2Cl2/PE to give N-{2-[1-(2,4-bistrifluoromethylbenzyloxyimino)ethyl]-4-chlorophenyl}trifluoromethanesulfonamide 2 (240 mg, 89%), as a colorless oil. 1H n.m.r. (200 MHz, CDCl3) δ 10.96, br s, 1H; 7.96, s, 1H; 7.85, d, J=8.0 Hz, 1H; 7.72, d, J=8.0 Hz, 1H; 7.60, d, J=8.8 Hz, 1H; 7.49, d, J=2.2 Hz, 1H; 7.33, dd, J=2.2 and 8.8 Hz, 1H; 5.46, s, 2H; 2.39, s, 3H. HRMS (M+) 542.0102.

1. concentrationThe reaction mixture was concentrated under vacuum
2. filtrationthe residue filtered through a pad of silica (eluting with CH2Cl2/PE, 7:3)
3. customPurification
4. washby radial thin layer chromatography (eluting with CH2Cl2/PE, 7.5:92.5 to 1:9)
5. customafforded a pale yellow solid which
6. customwas recrystallized from CH2Cl2/PE