Trichloroacetyl chloride → 2,2,2-Trichloro-1-[5-(1-methyl-1H-pyrazol-4-yl)-1H-pyrrolo[2,3-b]pyridin-3-yl]ethanone

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Reaction Steps

76.3 g of AlCl3 are suspended in 600 ml of dichloroethane under argon, and 22.7 g of the product 2 prepared above are incorporated in portions. During this addition, the orange solution changes colour to dark brown. After 10 min, 19.2 ml of trichloroacetyl chloride are slowly added dropwise. The reaction batch is cooled here using a water bath. When the addition is complete, the mixture is stirred at RT for a further 6 h before the suspension is filtered off with suction and the filter cake is washed with dichloromethane and water. The filter cake is transferred into a flask, and water is carefully added with ice-water cooling. The beige solid is filtered off with suction, likewise rinsed and subsequently dried at 70° C. in a vacuum drying cabinet for 3 h, giving 20.6 g. The acidic mother liquor is poured into ice-water, the suspension is likewise filtered off with suction as described above and dried, giving 10.3 g. The mother liquor is left to stand for 12 h, and precipitated product is filtered off with suction and dried, giving 0.4 g. The solids are combined; HPLC-MS: Rt=2.132 min; [M+H+]: 345.0.

Provenance & Evidence