Triethylsilane → 5-(2-Chloroethyl)-6-chlorooxindole

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Reaction Steps

A 2 L round-bottom flask is loaded with 300 g (1.22 mols) of 6-chloro-5-(2-chloro-1-hydroxy-ethyl)-1,3-dihydro-indol-2-one and 1140 ml of trifluoroacetic acid, under nitrogen atmosphere. The mixture is stirred at room temperature for 1 h, then heated to about 35-40° C. 214 ml (1.34 mols) of triethylsilane are then dropped therein in approx. 1 hr 30 min, keeping stirring for 12-14 h. Separately, a round-bottom flask is loaded with 3000 g of a water/ice mixture and the reaction mixture is carefully dropped therein, in about 1 hr 30 min, under strong stirring. The resulting white suspension is stirred for 30 min, then filtered, washed with purified water (4×500 ml) and heptane (400 ml), then dried at 60° C. under vacuum to afford 281 g of 6-chloro-5-(2-chloro-ethyl)-1,3-dihydro-indol-2-one.

Provenance & Evidence