Potassium Carbonate → 3-{3-[N-(2-(3,4-Dimethoxyphenyl)-ethyl)-N-methylamino]-propyloxy}-5-(3,4-dimethoxyphenyl)-pyrazole

Beteiligte Stoffe

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Reaktionsschritte

17 g of 5-(3,4-dimethoxyphenyl)-pyrazolin-3-one were dissolved in 200 ml of dimethylformamide. 11 g of potassium carbonate were added to the solution and the reaction mixture was heated at 100° C. under a nitrogen atmosphere for 0.5 hours. A solution of 21 g of 3-[N-(2-(3,4-di-methoxyphenyl)-ethyl)-N-methylamino]-propylchloride in 150 ml of dimethylformamide was then added dropwise. After 2 hours the salts which formed were filtered out, the filtrate was evaporated to dryness, and the residue was dissolved in ethyl acetate. The solution was subsequently washed with 7% strength aqueous sodium hydroxide solution in order to remove unreacted 5-(3,4-dimethoxyphenyl)-pyrazolin-3-one, dried with sodium sulfate and evaporated to dryness. The residue which remained was 35 g of oily crude product. This product was purified by chromatography over finely particulate silica gel under slightly elevated pressure (flash chromatography) using tert-butyl methyl ether/methanol 10:1 as eluent. 22.3 g of the title compound were obtained as an oil. IR spectrum of the base (as film): 1513 cm-1, 1260 cm-1, 1236 cm-1.

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