Phosphorus oxychloride → Methyl 5-(acetoxymethyl)-7-chloro-s-triazolo[1,5-a]pyrimidine-2-carboxylate
Reaktionsgleichung
[C:1]([O:4][CH2:5][C:6]1[NH:7][C:8]2[N:9]([N:13]=[C:14]([C:16]([O:18][CH3:19])=[O:17])[N:15]=2)[C:10](=O)[CH:11]=1)(=[O:3])[CH3:2].P(Cl)(Cl)([Cl:22])=O>>[C:1]([O:4][CH2:5][C:6]1[CH:11]=[C:10]([Cl:22])[N:9]2[N:13]=[C:14]([C:16]([O:18][CH3:19])=[O:17])[N:15]=[C:8]2[N:7]=1)(=[O:3])[CH3:2]Komponenten
3
Versuchsvorschrift
A suspension of 100 mg (0.38 mmol) of methyl 5-(acetoxymethyl)-4,7-dihydro-7-oxo-s-triazolo[1,5-a]pyrimidine-2-carboxylate in 7 ml of phosphorus oxychloride is held under reflux for 6 hours and subsequently concentrated in a vacuum. The residue is dissolved in dichloromethane. The solution is washed with ice/water, dried over sodium sulphate and concentrated. After crystallization from methanol/diethyl ether there are obtained 70 mg of methyl 5-(acetoxymethyl)-7-chloro-s-triazolo[1,5-a]pyrimidine-2-carboxylate as brown crystals of melting point 120° C.
Aufarbeitung
- temperatureunder reflux for 6 hours