反应详情

A solution of N-(2-acetyl-4-chlorophenyl)trifluoromethanesulfonamide 19 (310 mg, 1.03 mmol), O-(3-trifluoromethylphenyl)hydroxylamine hydrochloride (220 mg, 1.03 mmol) and anhydrous NaOAc (93 mg, 1.13 mmol) in EtOH (18 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, 3:2). Purification by radial thin layer chromatography (eluting with CH2Cl2/PE, 1:5) afforded N-{4-chloro-2-[1-(3-trifluoromethylphenoxyimino)ethyl]phenyl}trifluoromethanesulfonamide 134 (430 mg, 91%), as a pale yellow solid. M.p. 63-64° C. 1H n.m.r. (200 MHz, CDCl3) δ 11.00, br S, 1H, 7.71, d, J=9.0 Hz, 1H, 7.60, d, J=2.2 Hz, 1H, 7.56-7.35, m, 5H, 2.58, s, 3H. O-(3-Trifluoromethylphenyl)hydroxylamine hydrochloride was prepared in two steps by the procedure of Petrassi, M. H.; Sharpless, K. B.; Kelly, J. W. Org. Lett., 2001, 3, 139-142.

1. concentrationThe reaction mixture was concentrated under vacuum
2. filtrationthe residue filtered through a pad of silica (eluting with CH2Cl2/PE, 3:2)
3. customPurification
4. washby radial thin layer chromatography (eluting with CH2Cl2/PE, 1:5)