sentences:  In a recent study, Sloop investigated how substituents would influence the regioselectivity of the product as well as the rate of reaction during the rate-determining step in a modified Combes pathway, which produced trifluoromethylquinoline as the product.Sloop focused specifically on the influences that substituted trifluoro-methyl-β-diketones and substituted anilines would have on the rate of quinoline formation.One modification to the generic Combes quinoline synthesis was the use of a mixture of polyphosphoric acid (PPA) and various alcohols (Sloop used ethanol in his experiment).