反应详情

The product of step (a) (10.0 g, 35.2 mmol) was dissolved in chloroform (250 mL) in a 500 mL flask under a nitrogen atmosphere. Bromine (1.63 mL, 31.7 mmol) dissolved in chloroform (50 mL) was added using a dropping funnel over 30 min. The reaction mixture was stirred for 2.5 h and then concentrated to give a solid. The solid was dissolved in toluene (150 mL) with some gentle heat, followed by the addition of ethyl ether (150 mL) to yield the title compound as a crystalline solid (55% yield).

1. additionwas added
2. customover 30 min
3. concentrationconcentrated
4. customto give a solid