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  STEP A: 3-(2-nitro-4-chlorophenyl)pyruvic acid To a cooled mixture prepared by adding 13.6 g. of sodium to 300 ml. of ethanol is added a solution of 100 g. of 4-chloro-2-nitrotoluene and 84 g of diethyloxalate in 150 ml of ethanol while maintaining the temperature below 20℃. The resulting mixture is refluxed for one hour, cooled, 400 ml. of water added and the resulting mixture refluxed for 90 minutes. The ethanol is then evaporated to a small volume and the resulting precipi tate containstan and black material and the black mate rial is mechanically separated and discarded and the remainder (filtrate plus tan precipitate) used in the next step. STEP B: 4-chloro-2-nitro-phenylacetic acid The filtrate of Step A, above, is adjusted to pH 8-9 with 2 N sodium hydroxide and is heated at 35-40℃. while adding a 3-6% aqueous hydrogen peroxide solution until samples no longer turn dark on treatment with 2N sodium hydroxide. The tan precipitate is suspended in 1500 ml of water, adjusted to pH 8-9 and similarly treated with aqueous hydrogen peroxide. The combined reaction mixtures are then acidified with concentrated hydrochloride acid to obtain a precipitate which are re covered by filtration, washed 3 times with water and dried in vacuo. The crude product (mp 145-150° C) is recrystallized from ether to obtain 4-chloro-2-nitro phenylacetic acid, m.p. 156-159℃. STEP C: The product of Step B, above, is subjected to reductive cyclization analogously to Step B of Example 1 to obtain 6-chloro-oxindole, m.p. 185-189℃.;

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