2,4-Dimethoxybenzylamine → 1-(2,4-Dimethoxy-benzyl)-2-oxo-1,2-dihydro-pyridine-3,4-dicarboxylic acid 4-ethyl ester 3-methyl ester

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Reaction Steps

A mixture of 5-dimethylamino-3-ethoxycarbonyl-2-methoxycarbonyl-penta-2,4-dienoic acid methyl ester (14.7 g, 51.7 mmol) and 2,4-dimethoxybenzylamine (8.2 mL, 54.3 mmol) in EtOH (90 mL) was refluxed for 5 h. The mixture was cooled to r.t., concentrated in vacuo, and the residual oil was partitioned between ether and 1 M HCl. The aqueous layer was extracted with additional ether, and the organic layers were combined, washed with water, and dried over MgSO4. Evaporation of the solvent in vacuo afforded 18.4 g of the title compound as a viscous orange oil. MS: (+) m/z 398.23 (M+Na).

Provenance & Evidence