反应详情

A mixture of 3.1 g of 1,2-dihydro-5-(imidazo[1,2-a]-pyridin-6-yl)-6-methyl-2-oxo-3-pyridinecarbonitrile, 30 ml of phosphorous oxychloride and 5 drops of dimethylformamide was stirred under reflux for 2 hours. An excess of phosphorous oxychloride was removed by distillation under reduced pressure and upon cooling, chloroform, a 20% NaOH solution and then an aqueous sodium carbonate solution were added to the residue to render alkaline. The organic layer was taken by fractionation. After the chloroform layer was dried over magnesium sulfate, chloroform was removed by distillation. The residue was purified by column chromatography to obtain 1.9 g of 2-chloro-5-(imidazo[1,2-a]pyridin-6-yl)-6-methyl-3-pyridinecarbonitrile.

1. temperatureunder reflux for 2 hours
2. customAn excess of phosphorous oxychloride was removed by distillation under reduced pressure
3. temperatureupon cooling
4. additionchloroform, a 20% NaOH solution and then an aqueous sodium carbonate solution were added to the residue
5. dry with materialAfter the chloroform layer was dried over magnesium sulfate, chloroform
6. customwas removed by distillation
7. customThe residue was purified by column chromatography