反应详情

Methyl 2-(acetoxymethyl)-4,7-dihydro-7-oxo-s-triazolo[1,5-a]pyrimidine-5-carboxylate (500 mg) (1.87 mmol) are suspended in 20 l of phosphorus oxychloride. The suspension is held under reflux for 5 hours. The mixture is concentrated in a water-jet vacuum, the residue is treated with dichloromethane and ice/water and extracted several times with dichloromethane. After drying and evaporation of the extract the product is crystallized from methanol. There are obtained 400 mg of methyl 2-(acetoxymethyl)-7-chloro-s-triazolo[1,5-a]pyrimidine-5-carboxylate.

1. temperatureunder reflux for 5 hours
2. concentrationThe mixture is concentrated in a water-jet vacuum
3. additionthe residue is treated with dichloromethane and ice/water
4. extractionextracted several times with dichloromethane
5. customAfter drying
6. customevaporation of the
7. extractionextract the product
8. customis crystallized from methanol