反应详情

A solution of the diamine product of step (b) (4.75 g) in 48% aqueous hydrobromic acid (70 ml) was heated under reflux in an atmosphere of nitrogen for 3.5 hours. The solid which formed on cooling was filtered off and crystallised from ethanol, to give the title compound as the dihydrobromide salt, (3.1 g), mp 227°-228°.

1. temperatureunder reflux in an atmosphere of nitrogen for 3.5 hours
2. customThe solid which formed
3. temperatureon cooling
4. filtrationwas filtered off
5. customcrystallised from ethanol