反应详情

A mixture of 3-benzhydryl-5-(2-(benzyloxy)-5-methylphenyl)benzo[d]oxazol-2(3H)-one (1.0 g, 2.0 mmol) and palladium on activated charcoal (10% w/w, 0.20 g) in ethyl acetate/methanol (1:1 v/v, 20 mL) was stirred under an atmosphere of hydrogen (1 atm) for 16 h. The reaction mixture was filtered through a pad of diatomaceous earth and the pad was washed with ethyl acetate/methanol (1:1 v/v, 20 mL). The filtrate and washes were combined and concentrated in vacuo. The residue was purified by column chromatography eluting with a 20-65% gradient of ethyl acetate in hexanes to afford 3-benzhydryl-5-(2-hydroxy-5-methylphenyl)benzo[d]oxazol-2(3H)-one as a colorless solid in 98% yield (0.80 g): 1H NMR (300 MHz, CDCl3) δ 7.38-7.32 (m, 6H), 7.30-7.24 (m, 5H), 7.17-7.12 (m, 1H), 6.99 (dd, J=8.2, 1.6 Hz, 1H), 6.84 (s, 1H), 6.79-6.73 (m, 2H), 6.51 (s, 1H), 4.68 (s, 1H), 2.24 (s, 3H); MS (ES+) m/z 407.8 (M+1).

1. filtrationThe reaction mixture was filtered through a pad of diatomaceous earth
2. washthe pad was washed with ethyl acetate/methanol (1:1 v/v, 20 mL)
3. concentrationconcentrated in vacuo
4. customThe residue was purified by column chromatography
5. washeluting with a 20-65% gradient of ethyl acetate in hexanes