Dimethylformamide → 5-chloro-2-[3-(2-phthalimidoacetamidomethyl)-5-propargyloxymethyl-4H-1,2,4-triazol-4-yl]-benzophenone

Beteiligte Stoffe

Reaktionsschritte

A mixture of the above product (817 mg) and 27.5% hydrogen bromide/acetic acid (3 ml) is stirred at room temperature for 1.5 hours. The resultant solution is mixed with dry ether (30 ml) to give a precipitate. The precipitate is washed with dry ether (20 ml) twice to give 5-chloro-2-(3-aminomethyl-5-propargyloxymethyl-4H-1,2,4-triazol-4-yl)-benzophenone hydrobromide. To a suspension of this hydrobromide in dry benzene (20 ml), 2-phthalimidoacetyl chloride (1.6 g) is added at room temperature. The resultant mixture is mixed with dry dimethylformamide (10 ml) and stirred at room temperature for 3 hours. The reaction mixture is poured into saturated aqueous sodium bicarbonate (50 ml)/water (50 ml) and stirred under ice-cooling for 30 minutes. The precipitate is filtered, washed with water and ether in order and dissolved in methylene chloride (about 50 ml). The organic layer is dried over magnesium sulfate and evaporated to remove the solvent. The residue is recrystallized from methylene chloride/ethanol to give 5-chloro-2-[3-(2-phthalimidoacetamidomethyl)-5-propargyloxymethyl-4H-1,2,4-triazol-4-yl]-benzophenone (682 mg) as crystals melting at 245° to 246° C. (decomp.).

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