反应详情

Under a nitrogen atmosphere a solution of 1,4-diiodo-2-nitrobenzene (3.0 g, 8.0 mmol) in anhydrous THF (20 mL) was cooled to minus 40° C., and then a solution of phenylmagnesium chloride (2 M in THF, 4.8 mL, 9.6 mmol) was added dropwise at a rate that the temperature would not exceed minus 35° C. Upon completion of the addition the mixture was stirred for ten minutes, followed by addition of trimethylacetaldehyde (1.2 mL, 11.2 mmol), and the mixture was stirred for 30 minutes at minus 40° C. The mixture was gradually warmed up to room temperature, quenched with saturated ammonium chloride (60 mL), poured into water (120 mL), and extracted with ethyl acetate twice (60 mL each). The combined organic phase was washed with water (60 mL), dried over Na2SO4, and concentrated in vacuo. The residue was purified by silica gel column chromatography to yield racemic (RS)-1-(4-iodo-2-nitrophenyl)-2,2-dimethyl-1-propanol (2.17 g, 81%) as a brown oil. 1H NMR (400 MHz, CDCl3): δ 8.04 (d, 1H, J=1.6 Hz, Ph-H), 7.88 (dd, 1H, J=1.6 and 8.4 Hz, Ph-H), 7.51 (d, 1H, J=8.4 Hz, Ph-H), 5.28 (d, 1H, J=3.6 Hz, Ph-CH), 2.29 (d, 1 H, J=3.6 Hz, OH), 0.85 (s, 9H, C(CH3)3). 13C NMR (100 MHz, CDCl3): δ 149.87 (C), 141.0 (CH), 136.2 (C), 132.3 (CH), 131.63 (CH), 91.85 (C), 74.33 (CH), 36.81 (C), 25.6 (CH3).

1. customexceed minus 35° C
2. additionUpon completion of the addition the mixture
3. stirringthe mixture was stirred for 30 minutes at minus 40° C
4. customquenched with saturated ammonium chloride (60 mL)
5. additionpoured into water (120 mL)
6. extractionextracted with ethyl acetate twice (60 mL each)
7. washThe combined organic phase was washed with water (60 mL)
8. dry with materialdried over Na2SO4
9. concentrationconcentrated in vacuo
10. customThe residue was purified by silica gel column chromatography