ClC1C=C(Cl)C=C(Cl)C=1[O:10][C:11](=O)[CH2:12][C:13](OC1C(Cl)=CC(Cl)=CC=1Cl)=[O:14].[NH2:26]/[C:27](/[CH3:34])=[CH:28]\[C:29]([O:31][CH2:32][CH3:33])=[O:30].C(OCC)(=O)C.CCOCC>BrC1C=CC=CC=1>[CH2:32]([O:31][C:29]([C:28]1[C:13]([OH:14])=[CH:12][C:11](=[O:10])[NH:26][C:27]=1[CH3:34])=[O:30])[CH3:33]
A mixture of malonic acid bis(2,4,6-trichloro-phenyl)ester (13.3 g, 0.03 mol) and ethyl 3-aminocrotonate (3.87 g, 0.03 mol) in bromobenzene (25 mL) is heated at 155° C. for 30 minutes. The mixture is cooled to room temperature. Ethyl acetate (50 mL) and ether (50 mL) are added. The solid is collected and purified by filtration through a short silica gel column (25% ethyl acetate/ether) to give 4-hydroxy-2-methyl-6-oxo-1,6-dihydropyridine-3-carboxylic acid ethyl ester. 1H NMR: (CDCl3) 5.85 (s, 1H), 4.38 (q, 2H), 2.68 (s, 3H), 1.39 (t, 3H).
Wird geladen…
