Diethyl Ether → 3,5-Dichloro-3-(2-methoxyphenyl)indolin-2-one

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Reaction Steps

This compound is prepared according to the procedure disclosed in WO 95/18105. A solution of 2-methoxyphenylmagnesium bromide is prepared from 16 g of magnesium in 35 ml of ether and from a solution of 124 g of 1-bromo-2-methoxybenzene in 175 ml of ether. This solution is added dropwise, under an argon atmosphere, to a mixture of 30 g of 5-chloro-1H-indole-2,3-dione in 250 ml of THF, cooled beforehand in a bath of ice, and the mixture is then left stirring while allowing the temperature to return to RT. After stirring for one hour at RT, the reaction mixture is poured slowly into saturated NH4Cl solution and the THF is evaporated off under vacuum. The precipitate formed is spin-filtered off and washed with iso-ether. 42 g of the expected product are obtained and are used in the next step without further purification.

Provenance & Evidence