反应详情

A mixture of 1-bromo-3-chloro-5-fluorobenzene (1.47 g, 7.01 mmol), magnesium turnings (0.82 g, 31.1 mmol) and a small piece of iodine in dry tetrahydrofuran (50 mL), under nitrogen was gently heated until reaction started and stirred for 1 h at ambient temperature after which a solution of 1-Boc-3-azetidinone (1.0 g, 5.85 mmol) in dry diethyl ether (10 mL) was added dropwise. The resulting mixture was stirred for 15 min and water (70 ml) and saturated aqueous ammonium chloride (20 mL) was added and the mixture was extracted with ethyl acetate (2×50 ml). The combined organic phase was dried (Na2SO4), filtered and evaporated to dryness. The crude product was purified by flash column chromatography on silica gel (ethylacetate/isooctane 1:4 to 1:1) to give the title compound (1.25 g). MS m/z (rel. intensity, 70 eV) 285 (M+, 1), 156 (60), 141 (43), 127 (80), 57 (bp).

1. additionwas added dropwise
2. extractionthe mixture was extracted with ethyl acetate (2×50 ml)
3. dry with materialThe combined organic phase was dried (Na2SO4)
4. filtrationfiltered
5. customevaporated to dryness
6. customThe crude product was purified by flash column chromatography on silica gel (ethylacetate/isooctane 1:4 to 1:1)