Diethyl (ethoxymethylene)malonate → HCID 13825638, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of 19 g of 5-acetamido-1,2,3,4-tetrahydroquinaldine and 24.0 g of diethyl ethoxymethylenemalonate was heated at 160° C. for 2 hours. The product obtained was not purified. To the mixture was added 60 g of polyphosphoric acid, and the mixture was heated at 100° C. for one hour. To the mixture was added 400 ml of warm water. The mixture was basified and cooled. The solid residue was separated by decantation to provide ethyl 8-acetamido-6,7-dihydro-5-methyl-1-oxo-1H,5H-benzo[ij]quinolizine-2-carboxylate. Next the solid was dissolved in 20 ml of methanol, and to this solution was added 80 ml of ten percent sodium hydroxide solution. The solution was heated on a steam bath for one hour, followed by the addition of 20 ml of concentrated ammonium hydroxide. The solution was acidified to pH 6 with acetic acid. A solid precipitate formed which was separated by filtration and recrystallized from aqueous N,N-dimethylformamide to provide brown crystals of 8-amino-6,7-dihydro- 5-methyl-1-oxo-1H,5H-benzo[ij]quinolizine-2-carboxylic acid. The structure was confirmed by infrared and nuclear magnetic resonance spectral analysis.

Provenance & Evidence