2-Oxoglutaric Acid → 2-(5,6-Dihydro-4H-pyrrolo[3,2,1-ij]quinolin-1-yl)acetic acid

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Reaction Steps

17 g of 1-amino-1,2,3,4-tetrahydroquinoline (preparation see Example 1B) and 20 g of 2-ketoglutaric acid were heated under reflux at a temperature of 80° C. for 2 hours in a mixture of 160 ml of acetic acid and 11.4 ml of concentrated hydrochloric acid. To work up the reaction mixture the solid residue which remained was taken up in water and extracted with ethyl acetate. The organic phase was separated and extracted with 20% strength aqueous sodium hydroxide solution. The alkaline (pH=9) aqueous phase was separated and acidified to pH=4 by addition of aqueous 10% strength hydrochloric acid solution, and a precipitate formed. The solution was extracted with ethyl acetate. The organic phase was evaporated. 10.6 g of crude 5,6-dihydro- 4H-pyrrolo-[3,2,1-ij]quinoline-1-acetic acid were obtained as a solid residue.

Provenance & Evidence