Fuming sulfuric acid → Sulfuric Acid

Participants

Reaction Steps

It should, however, be noted that, in the particular case of the cyclisation of 3-(m-chloroanilino)propionic acid by polyphosphoric acid, a mixture of substantially equal quantities of 5-chloro- and 7-chloro-1,2,3,4-tetrahydro-4-quinolinone is obtained. The selectivity for 7-chloro-1,2,3,4-tetrahydro-4-quinolinone is significantly improved if an oleum or a hydrofluoric acid/boron trifluoride mixture is used as cyclisation agent, but the industrial use of these processes encounters difficulties which result either from the handling of large quantities of sulphuric acid or from the utilisation of a mixture of anhydrous hydrofluoric acid and boron trifluoride.

Provenance & Evidence