Ethane → 2-Methyl-3-[gamma-(4-phenylpiperazino)propyl]indole

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Reaction Conditions

Reaction Steps

Ethylmagnesium iodide was prepared from 31.9 g of ethyl iodide and 5.0 g of magnesium in 100 ml of dry anisole and the mixture was heated for 1 hour at 50°-60°C. It was then cooled at 10°C, and while a solution of 2-methylindole (13.1 g) in dry anisole (50 ml) was added thereto, the temperature was maintained below 25°C. The mixture was then heated at 50°C until the evolution of ethane ceased. The resulting solution was cooled to -5°C in a cold bath, and a solution of 1-(γ-chloropropyl)-4-phenylpiperazine (52.5 g) in 100 ml of dry benzene was added during 1 hour at a temperature of -5° ± 2°C. The mixture was then stirred for 3 hours at -5°C and allowed to stand in a refrigerator overnight. The mixture was warmed to 20°-25°C for several hours. The precipitate was broken up and the mixture was poured into saturated aqueous ammonium chloride (500 ml) and stirred for 1 hour. The organic layer was separated, and the aqueous layer was extracted with ethyl acetate. The organic solutions were combined and extracted three times with 10 % hydrochloric acid. The extracts were washed with ethyl acetate, cooled to 0°C, made alkaline with 50 % sodium hydroxide, and extracted three times with ethyl acetate. These extracts were dried over anhydrous sodium sulfate and evaporated to afford 2-methyl-3-[γ-(4-phenylpiperazino)propyl]indole as an oil which solidified by treating with benzene. Recrystallization from benzene gave needles, melting point 130.5°-131.5°C.

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