Hydrochloric Acid → 2-Carboxy-4,7-dihydro-4,7-dioxo-6-(carboxymethyl)oxy-1H-cyclohepta[b]pyridine-1-acetic acid

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Reaction Steps

A mixture of 4,7-dihydro-4,7-dioxo-2-ethoxycarbonyl-6-[(2-ethoxy-2-oxoethyl)oxy]-1H-cyclohepta[b]pyridine-1-acetic acid ethyl ester (1.72 g, described in Example 15) and 2N potassium hydroxide (12 ml) is stirred at room temperature for 2.5 hr and 19% hydrochloric acid is added until the mixture is acidic. The precipitate is collected and washed with water, acetone and ether to obtain the title compound. The precipitate is dissolved in aqueous aminoethanol (1M, 4 ml) and acetone (50 ml is added). The precipitate is collected, washed with acetone and crystallized from water-acetone to give crystals of the aminoethanol salt of the title compound, mp 236°-237° C.

Provenance & Evidence