2, 5-Dimethylindole is a kind of carbazole-system derived indole compound, which is valuable in the manufacturing of perfume. It is also a useful chemical intermediate. It is usually used as reactant in the following reaction: stereoselective synthesis of indolines via palladium-catalyzed asymmetric hydrogenation of unprotected indoles; stereoselective preparation of substituted indoles via rhodium-catalyzed enantioselective coupling reaction of indoles with diazo compounds; enantioselective synthesis of fluorene derivatives via Friedel-Crafts reactions; preparation of bis-indolyldihydroxybenzoquinones by addition indoles to dichlorobenzoquinone promoted by Bronsted acid; Reaction with hydroxypyrazolines.