Water → Flosequinoxan

Participants

Reaction Steps

A mixture of 5'-fluoro-N-methyl-2'-methylsulphonylacetylformanilide (5.0 g), prepared in a similar manner to that described in Example 11, water (50 ml) and isopropyl alcohol (50 ml) was heated to 50°. Aqueous sodium hydroxide solution (1 M; 3 ml) was added and the mixture heated under reflux for 2.5 hours. The mixture was cooled in an ice bath and the product isolated by filtration, washed with water (10 ml), and then isopropyl alcohol (10 ml) to give the crude product (3.3 g). A sample of the crude product (2.0 g) was crystallised from industrial methylated spirit (112 ml) to give 7-fluoro-1-methyl-3-methylsulphonyl-4-quinolone, m.p 221.5°-223° (1.7 g). The product was heated at 90° with grinding to give 7-fluoro-1-methyl-3-methylsulphonyl-4-quinolone, m.p. 235°-236° (1.7 g).

Provenance & Evidence