To a solution of [3-({4-[2-(2,4-difluorophenyl)ethyl]phenyl}sulfonyl)phenyl]methanol (prepared from 3-({4-[E)-2-(2,4-difluorophenyl)vinyl]phenyl}sulfonyl)benzaldehyde (Example 50 Step 1) according to the method of Example 117) in dichloromethane (4 mL) was added 4 Å molecular sieves (0.1 g) and the mixture stirred for 10 minutes. 4-Methylmorpholine N-oxide (68 mg, 0.58 mmol) was added in one portion and the reaction stirred for 10 minutes, then tetrapropylammonium perruthenate (6.9 mg, 0.02 mmol) added. The reaction was stirred for 30 minutes then diluted with ethyl acetate, filtered through a pad of silica and washed with further ethyl acetate. The filtrate was evaporated in vacuo. The residue was purified by flash column chromatography on silica, eluting with 25% ethyl acetate/isohexane, to yield 3-({4-[2-(2,4-difluorophenyl)ethyl]phenyl}sulfonyl)benzaldehyde (103 mg, 68%). δH (400 MHz, CDCl3): 10.06 (1H, s), 8.40 (1H, s), 8.18 (1H, d, J=7.8 Hz), 8.07 (1H, d, J=7.6 Hz), 7.87 (2H, d, J=8.3 Hz), 7.69 (1H, t, J=7.7 Hz), 7.30 (2H, d, J=8.2 Hz), 6.99 (1H, q, J=7.9 Hz), 6.79–6.73 (2H, m), 2.95–2.87 (4H, m). m/z ES+) 387 [MH+].
