Acetic Acid → 1,4-Dimethyl-2-quinolone

Participants

Reaction Conditions

Reaction Steps

The starting 1,2-dihydro-1,4-dimethyl-2-quinolone (3) is prepared by first conjugating N-methylaniline with diketene, followed by an acid cyclization of the amide intermediate. Thus 10.0 g (0.12 moles) of diketene is added dropwise to 10.7 g (0.1 moles) of N-methylaniline and the reaction is heated at 100 ° C. for an additional 30 minutes. To the resulting mixture is added 30 mL of acetic acid and 30 mL of sulfuric acid, and the mixture is heated at 50 ° C. overnight. The reaction is worked up with water and ethyl acetate and purified on a silica gel column to yield 9.5 g of the desired product.

Provenance & Evidence