反应详情

The mixture of carbonic acid 2,4-di-tert-butyl-5-nitro-phenyl ester methyl ester and carbonic acid 2,4-di-tert-butyl-6-nitro-phenyl ester methyl ester (4.2 g, 12.9 mmol) was dissolved in MeOH (65 mL) and KOH (2.0 g, 36 mmol) was added. The mixture was stirred at room temperature for 2 h. The reaction mixture was then made acidic (pH 2-3) by adding conc. HCl and partitioned between water and diethyl ether. The ether layer was dried (MgSO4), concentrated and purified by column chromatography (0-5% ethyl acetate-hexanes) to provide 2,4-di-tert-butyl-5-nitro-phenol (1.31 g, 29% over 2 steps) and 2,4-di-tert-butyl-6-nitro-phenol. 2,4-Di-tert-butyl-5-nitro-phenol: 1H NMR (400 MHz, DMSO-d6) δ 10.14 (s, 1H, OH), 7.34 (s, 1H), 6.83 (s, 1H), 1.36 (s, 9H), 1.30 (s, 9H). 2,4-Di-tert-butyl-6-nitro-phenol: 1H NMR (400 MHz, CDCl3) δ 11.48 (s, 1H), 7.98 (d, J=2.5 Hz, 1H), 7.66 (d, J=2.4 Hz, 1H), 1.47 (s, 9H), 1.34 (s, 9H).

1. custompartitioned between water and diethyl ether
2. dry with materialThe ether layer was dried (MgSO4)
3. concentrationconcentrated
4. custompurified by column chromatography (0-5% ethyl acetate-hexanes)