反应详情

To a solution of above-mentioned (a) (9.5 g, 53 mmol) in acetic acid (28 ml) was added dropwise a solution of bromine (6.1 ml, 0.12 mol) in acetic acid (28 ml) at 115° C. over a period of 45 minutes, and heated under reflux for 1 hr. The reaction solution was left overnight, and the precipitated crystals were collected by filtration, washed with diethyl ether, followed by drying to give 3.5 g of the title compound.

1. temperatureheated
2. temperatureunder reflux for 1 hr
3. filtrationthe precipitated crystals were collected by filtration
4. washwashed with diethyl ether
5. customby drying