Water → HCID 13055798, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of 0.0894 mole (1.7 g) of optically purified (+) 1-acetyl-3-methyl-1,2,3,4-tetrahydroquinoxaline and 0.009 mole (1.9 g) diethyl ethoxymethylenemalonate is heated over one hour to 200° C. and maintained at that temperature for 1.5 hours. After cooling, 5 g of polyphosphoric acid are added and the mixture is heated at 120° C. until foaming stops. The mixture is stirred into water and the solution is made strongly basic with 25 percent sodium hydroxide. The solution is stirred and heated on a steam bath for one hour, then neutralized with acetic acid. Cooling, followed by filtration provides an olive green solid R(+) 2,3-dihydro-3-methyl-7-oxopyrido[1,2,3-de]quinoxaline-6-carboxylic acid, m.p.>250° C. Analysis: Calculated for C13H12N2O3 : %C, 63.9; %H, 5.0; %N, 11.5; Found: %C, 63.4; %H, 5.0; %N, 11.6. Optical rotation [α]21D =93±3+(C= 0.594, N,N-dimethylformamide: ethanol, 1/1).

Provenance & Evidence