反应详情

[4-Nitro-3-(2,2,2-trifluoro-ethoxy)-phenyl]-acetic acid methyl ester (33 g, 94.5 mmol) and (bromomethyl)cyclobutane (17 g, 114.1 mmol) were mixed in DMSO (50 mL) and KOH (6.4 g, 114.1 mmol) was added in portions over 15 min. The reaction mixture was stirred for 16 h and water (100 mL) was added. The reaction mixture was extracted with EtOAc (3×50 mL). The combined organic phases were dried over MgSO4 and evaporated to give a crude yellow oil, which was purified by silica gel gradient column chromatography using Heptane-EtOAc (9:1-4:1) to give 15 g (40%) of the product as a yellow oil. (The synthesis was repeated with temperature kept at 40° C. over 16 h to give the product in quantitative yield). 1H NMR (300 MHz, CDCl3/TMS): δ 7.86 (d, J=8.0 Hz, 1H), 7.12-7.09 (m, 2H), 4.50 (q, J=7.7 Hz, 2H), 3.68 (s, 3H), 3.55 (t, J=7.3 Hz, 1H), 2.22-2.10 (m, 2H), 2.03-1.75 (m, 5H), 1.70-1.55 (m, 2H). 13C NMR (75 MHz, CDCl3/TMS): δ 172.9, 150.5, 146.4, 139.4, 126.0, 122.7, 122.6 (d, 1JCF=277.6 Hz), 116.0, 67.5 (q, 1JCF=36.7 Hz), 52.3, 49.6, 40.7, 33.9, 28.2, 27.9, 18.4.

1. extractionThe reaction mixture was extracted with EtOAc (3×50 mL)
2. dry with materialThe combined organic phases were dried over MgSO4
3. customevaporated
4. customto give a crude yellow oil, which
5. customwas purified by silica gel gradient column chromatography