Dimethylformamide → HCID 13336773, compound

Participants

Reaction Steps

(S)-N-Carbobenzyloxy-1,2,3,4-tetra-hydroquinoline-2-carboxylic acid was prepared as described in U.S. Pat. No. 4,461,896. To a solution of this acid (18.743 g., 60.3 mmole) in dry dimethylformamide (70 ml.) at room temperature under argon was added powdered potassium carbonate (10.5 g., 76 mmole) and methyl iodide (5.6 ml., 12.8 g., 90.0 mmole). After stirring for 2 hours, the mixture was partitioned between ethyl acetate (200 ml.) and 5% potassium bisulfate (200 ml.). The organic phase was washed with water (twice) and brine, dried (sodium sulfate) and evaporated to dryness. The crude product was taken up in methanol (150 ml.), treated with p-toluenesulfonic acid, monohydrate (12.03 g., 63.2 mmole) and 20% palladium hydroxide on carbon (0.2 g.) and stirred-under an atmosphere of hydrogen (balloon) for 1.5 hours. The mixture was filtered through Celite and concentrated to a small volume, causing a crystalline solid to separate. This material was triturated with ethyl ether and the solid was collected to give a total of 19.965 g. of the titled product.

Provenance & Evidence