Water → 5-Chloro-2-cyclopropyl-6-(4-fluorophenyl)-[1,2,4]triazolo[1,5-a]pyrimidine

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Reaction Steps

7.78 g (24.1 mmol) 5,7-Dichloro-2-cyclopropyl-6-(4-fluorophenyl)-[1,2,4]triazolo[1,5-a]pyrimidine are given in 612 mL ethanol, 435 mL water and 234 mL THF. After addition of 6.1 g (114 mmol) NH4Cl, 10.1 g (154 mmol) zinc powder are added and the mixture is stirred at room temperature for 3 h. Stirring is continued over night. The reaction mixture is filtered via a glass microfibre filter and the filter is washed with plenty of methanol. The zinc slurry is stirred twice with ethylacetate/methanol (250 mL each) and the combined organic filtrates are evaporated. The residue is extracted with ethyl acetate (1 L). The organic phase is washed twice with brine and dried over Na2SO4. After evaporation of the solvent, the residue is purified by chromatography on silicagel (eluents dichloromethane/methanol) yielding 0.76 g (10.4%) of the desired product. Additionally 3.57 g are obtained which are a mixture of the desired product and the bis deschloro derivate (ratio 6:4).

Provenance & Evidence