反应详情

To a solution of 27 parts of triphenylphosphine in a mixture of 195 parts of acetonitrile with 400 parts of carbon tetrachloride is added 12 parts of a 1:1 solvate of 2,3-dihydro-8-nitro-3-oxo-5H-pyrido[3,4-b][1,4]benzothiazine-4-carbonitrile 10-oxide with N,N-dimethylformamide. The resultant mixture is heated at the boiling point under reflux with stirring for 15 minutes, then chilled. The precipitate which forms is isolated by filtration and recrystallized from a mixture of N,N-dimethylformamide and methanol to give 2,3-dihydro-8-nitro-3-oxo-5H-pyrido[3,4-b][1,4]benzothiazine-4-carbonitrile solvated 2:1 with N,N-dimethylformamide which melts above 305°. The solvent of crystallization can be removed by heating at around 200° in vacuo.

1. temperatureunder reflux
2. temperaturechilled
3. customThe precipitate which forms is isolated by filtration
4. customrecrystallized from a mixture of N,N-dimethylformamide and methanol