Hydrochloric Acid → 6,7-Difluoro-2-methylquinoline

Participants

Reaction Conditions

Reaction Steps

To a refluxing solution of 3,4-difluoroaniline (2.30 ml, 23.2 mmoles), tetrachloro-1,4-benzoquinone (5.70 g, 23.2 mmoles), and concentrated hydrochloric acid (6 ml) in 2-butanol (40 ml) is added crotonaldehyde (1.92 ml, 23.2 mmoles). After 2.5 hours the reaction mixture is concentrated and the resulting residue is stirred in warm (50° C.) THF (15 ml). This mixture is cooled (0° C.) and the solid collected by filtration and washed with cold THF. The solid is stirred in distilled water (200 ml), and the resulting solution made basic with K2CO3 and extracted with EtOAc (3×100 ml). The organic extracts are combined and dried over sodium sulfate, and then concentrated to give the title compound. MS (ESI) 180 (M+H)+.

Provenance & Evidence