C(NC(C)C)(C)C.C([Li])CCC.[Cl:13][C:14]1[N:19]=[C:18]([Cl:20])[CH:17]=[C:16]([Cl:21])[N:15]=1.[C:22](=[O:24])=[O:23].Cl>CCCCCC.O1CCCC1.[Cl-].[Na+]>[C:22]([C:17]1[C:16]([Cl:21])=[N:15][C:14]([Cl:13])=[N:19][C:18]=1[Cl:20])([OH:24])=[O:23]A mixture of diisopropylamine 2.54 g, a 1.6M solution of n-butyl lithium in hexane 15.7 ml and tetrahydrofuran 100 ml is stirred for 30 minutes on a dry ice-acetone bath. Thereto is added 2,4,6-trichloropyrimidine 2.00 g in tetrahydrofuran 8 ml over a period of 30 minutes, followed by further one hour agitation. The reaction mixture is poured into dry ice, and the mixture is stirred for a hour at room temperature. The reaction mixture is made acidic with 10% hydrochloric acid 20 ml, diluted with an aqueous saturated sodium chloride solution and extracted with ethyl acetate. The organic layer is washed, dried and concentrated in vacuo. The solvent is removed by azeotrope with chloroform and the resulting hemisolid is triturated with hexane to give 5-carboxy-2,4,6-trichloropyrimidine as a crystalline powder, 1.51 g. mp 150-153° C.
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