HCID 3042017、化合物 → HCID 18919350、化合物

1,4-Dichloro-1-buten-3-one (10.9 g) (prepared in a manner analogous to the preparation of 1-chloro-4-methyl-1-penten-3-one described in Example 20 below), 3-amino-1,2,4-triazole (6.5 g) and glacial acetic acid were heated under reflux for 1 hour and 30 minutes. The reaction mixture was poured onto ice and extracted with dichloromethane. The organic layer was dried over magnesium sulphate and the solvent was evaporated to give a solid. The crude product was purified by flash chromatography using as eluent a mixture of dichloromethane and ethanol (in the ratio 97:3 respectively), followed by recrystallisation from tetrachloromethane, to give 7-chloromethyl-1,2,4-triazolo[1,5-a]pyrimidine. Yield 10.15 g.