Iodoethane → HCID 15675260, compound

Participants

Reaction Steps

3-Hydroxy-4-methoxyaniline (10.0 g) and diethyl ethoxymethylenemalonate (17.0 g) were condensed in the same manner as in the preparation of compound 72. The condensation product was O-ethylated with potassium carbonate (15.0 g) and ethyl iodide (7.0 ml) and then heated in diphenyl ether (70 ml) at a temperature of 240°-250° for 3 hours. After the mixture was left to cool, ether was added to the mixture. The resulting precipitate was collected by filtration, washed with water and dried to give 7-ethoxy-3-ethoxycarbonyl-6-methoxy-4(1H)-quinolone (10.2 g). The compound (5.0 g) was subjected to N-methylation and hydrolysis in the same manner as in Experimental Example 9 to obtain 3-carboxyl-7-ethoxy-6-methoxy-1-methyl-4(1H)-quinolone (compound 92, 4.4 g).

Provenance & Evidence