p-Dimethylaminobenzaldehyde (4-Dimethylaminobenzaldehyde) is an organic compound containing amine and aldehyde moieties which is used in Ehrlich's reagent and Kovac's reagent to test for indoles[1].
[1]. Axel Ehmann, et al. The van URK-Salkowski reagent — a sensitive and specific chromogenic reagent for silica gel thin-layer chromatographic detection and identification of indole derivatives. Journal of Chromatography A. Volume 132, Issue 2, 11 February 1977, Pages 267-276.