Dimethylformamide → HCID 20508775, compound

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Reaction Conditions

Reaction Steps

20.5 g. of 2-methoxy carbonyl-3-methoxy indole are dissolved in 100 ml. of dimethyl formamide. 3 g. of 80% sodium hydride are added portion by portion thereto at 0° C., while stirring. After heating the mixture to room temperature, 20 g. of 1-bromo-3-chloro propane are added thereto. The reaction mixture is heated to 80° C. for 12 hours whereupon the solvent is drawn off. The reaction mixture is worked up in the usual manner by means of ethyl acetate and water. The resulting crude reaction product is subjected to a distillation in a tubular distillation apparatus with bulbar enlargements. 24.7 g. of 1-(γ-chloro propyl)-2-methoxy carbonyl-3-methoxy indole are obtained in the form of an oil. Said compound is dissolved in 100 ml. of dimethyl formamide. The solution is then heated with 20 g. of diethylamine to 60° C. for 5 hours. After drawing off the solvent and adding 10% hydrochloric acid to the residue, the mixture is extracted with ethyl acetate. Thereupon the aqueous phase is rendered alkaline by the addition of a sodium carbonate solution and the mixture is extracted with ethyl acetate. The organic phase is dried over sodium sulfate, filtered, and the filtrate is evaporated to dryness under reduced pressure. 25.8 g. of 1-(γ-diethyl amino propyl)-2-methoxy carbonyl-3-methoxy indole are obtained as an oily residue. The yield is 81% of the theoretical yield. Said compound can be converted into its crystalline maleinate with a melting point of 110°-112° C.

Provenance & Evidence