反应详情

To a cooled (0° C.) solution of 3-chloro-5-fluoroaniline (5.0 g, 33 mmol) in MeCN (50 ml) was added a suspension of N-bromosuccinimide (5.9 g, 33 mmol) in MeCN (10 ml). After being stirred for 2 h at RT the reaction was quenched by adding 10% NaHSO3 (50 ml). The mixture was concentrated to about half of the volume, diluted with water (50 ml) and extracted with EtOAc (3×50 ml). Combined organic phases were dried over Na2SO4 and evaporated to give crude product, which was purified by CombiFlash (column: silica, eluent: 0-100% EtOAc in heptane) to yield 5.5 g (74%) of the title compound. 1H-NMR (400 MHz; d6-DMSO): δ 5.88 (bs, 2H), 6.45 (dd, 1H), 6.64 (m, 1H).

1. additionwas added
2. customwas quenched
3. additionby adding 10% NaHSO3 (50 ml)
4. concentrationThe mixture was concentrated to about half of the volume
5. additiondiluted with water (50 ml)
6. extractionextracted with EtOAc (3×50 ml)
7. dry with materialCombined organic phases were dried over Na2SO4
8. customevaporated
9. customto give crude product, which
10. customwas purified by CombiFlash (column: silica, eluent: 0-100% EtOAc in heptane)