Cl[C:2]1[N:7]2[CH:8]=[CH:9][N:10]=[C:6]2[N:5]=[C:4]([Cl:11])[C:3]=1[C:12]1[CH:17]=[CH:16][C:15]([F:18])=[CH:14][CH:13]=1.C1COCC1.O.[NH4+].[Cl-]>C(O)C.[Zn]>[Cl:11][C:4]1[C:3]([C:12]2[CH:17]=[CH:16][C:15]([F:18])=[CH:14][CH:13]=2)=[CH:2][N:7]2[CH:8]=[CH:9][N:10]=[C:6]2[N:5]=15.3 g (18.9 mmol) 5,7-Dichloro-6-(4-fluorophenyl)-imidazo[1,2-a]pyrimidine are given in 480 mL ethanol, 184 mL THF and 342 mL water. After addition of 4.7 g (89.5 mmol) NH4Cl and 7.9 g (120 mmol) zinc the mixture is vigorously stirred at rt for two and a half hours. The reaction mixture is filtered via a glass microfibre filter and washed with plenty of methanol. The solvent has been removed and the residue redissolved in ethyl acetate (1 L). After washing twice with brine the solvent is evaporated (without prior drying due to solid material in the solvent). 3.83 g (81.8%) of the desired product containing 11% of the bisdeschloro compound are obtained which is used without further purification.
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