反应详情

Thiourea (1.7 g) was added all at once to a solution of 4.2 g of 5,7-dichloro-s-triazolo[1,5-a]pyrimidine in 140 ml anhydrous ethanol at room temperature, the mixture was refluxed for 30 minutes, the crystals formed upon ice cooling were filtered off, and the filtrate was concentrated under reduced pressure. The residue was dissolved in 18 ml of 1N sodium hydroxide solution. The resulting solution was washed with 20 ml of ethyl acetate. The pH was adjusted to 1.0 with concentrated hydrochloric acid to give crystals. The crystals were collected by filtration and washed with 20 ml of water and then with 20 ml of methanol, affording 1.2 g of the objective compound as faint yellow crystals.

1. temperaturethe mixture was refluxed for 30 minutes
2. customthe crystals formed upon ice cooling
3. filtrationwere filtered off
4. concentrationthe filtrate was concentrated under reduced pressure
5. dissolutionThe residue was dissolved in 18 ml of 1N sodium hydroxide solution
6. washThe resulting solution was washed with 20 ml of ethyl acetate
7. customto give crystals
8. filtrationThe crystals were collected by filtration
9. washwashed with 20 ml of water