Diethyl Ether → 5-Chloro-3-hydroxy-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, cooled beforehand in an ice bath, of 30 g of 5-chloro-1H-indole-2,3-dione in 250 ml of THF and then the mixture is left stirring while allowing the temperature to rise to RT. After stirring for 1 hour at RT, the reaction mixture is slowly poured into saturated NH4Cl solution and the THF is evaporated off under vacuum. The precipitate formed is spin-filtered off and is washed with iso ether. 42 g of the expected product are obtained, which product is used without further purification in the following stage.

Provenance & Evidence