Reaktion #56026

Reaktionsgleichung

2,3-dihydro-3-oxo-5H-pyrido[3,4-b][1,4]benzothiazine-4-carbonitrile

acetic acid

bromine

→

8-bromo-2,3-dihydro-3-oxo-5H-pyrido[3,4-b][1,4]benzothiazine-4-carbonitrile

Lösungsmittel

carbon tetrachloride

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturunder reflux for 23/4 hours
2. 2
   Temperaturchilled
3. 3
   FiltrationThe precipitate which forms is filtered off
4. 4
   Sonstigerecrystallized from N,N-dimethylformamide

Vorschrift

To a solution of 20 parts of 2,3-dihydro-3-oxo-5H-pyrido[3,4-b][1,4]benzothiazine-4-carbonitrile in 1575 parts of glacial acetic acid is added a solution of 34 parts of bromine in 320 parts of carbon tetrachloride. The resultant mixture is heated at the boiling point under reflux for 23/4 hours, then chilled. The precipitate which forms is filtered off and recrystallized from N,N-dimethylformamide to give 8-bromo-2,3-dihydro-3-oxo-5H-pyrido[3,4-b][1,4]benzothiazine-4-carbonitrile melting above 305°.

Quelle