反应详情

A solution of 5-(4-benzyloxycarbonylaminophenyl)-2(1H)-pyrazinone (1.1 g) in 15% w/v hydrogen bromide in acetic acid solution (30 ml) was refluxed for 30 min. The yellow precipitate which formed was filtered off and it was washed with a little 1-propanol and then recrystallised from ethanol-water containing 2 drops of concentrated hydrobromic acid to give 5-(4-aminophenyl)-2(1H)-pyrazinone hydrobromide (1.03 g m.p.>300° C.).

1. temperaturewas refluxed for 30 min
2. customThe yellow precipitate which formed
3. filtrationwas filtered off
4. washit was washed with a little 1-propanol
5. customrecrystallised from ethanol-water containing 2 drops of concentrated hydrobromic acid