Pyruvic Acid → 5-(methoxycarbonyl)-1H-indole-2-carboxylic acid

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Reaction Steps

A solution of 25 g 4-Amino-3-iodo-benzoic acid methyl ester, 19 ml 2-Oxo-propionic acid, 30.4 g 1,4-Diaza-bicyclo[2.2.2]octane and 1 g Pd(OAc)2 was heated under argon to 100° C. After 5 h the reaction mixture was concentrated under reduced pressure and the residue was partitioned between 300 ml ethyl acetate and 200 ml 1 M hydrochloric acid. The organic layer was dried over MgSO4 and the solvent removed under reduced pressure to yield a yellow solid (6.4 g). From the aqueous layer additional product slowly precipitated as a white solid (7.9 g) which was collected by filtration. Both fractions were combined, dried in vacuo and used in the next reaction without further purification. Yield: 14.3 g MS (ES+): m/e=220.

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