Colored water immiscible organic liquid

Abstract

Novel disazo colorants or dyes for marking organic liquids, the colorants having the general formula ##STR1## where R.sub.1 is H, CF.sub.3, or alkyl having from 1 to 4 carbon atoms, R.sub.2 is H, or alkyl having from 1 to 4 carbon atoms, R.sub.3 and R.sub.4 are each H, OCH.sub.3, OC.sub.2 H.sub.5 or CH.sub.3, and R.sub.5, r.sub.6 and R.sub.7 are each H, or alkyl having from 1 to 12 carbon atoms, at least one of said R.sub.5, R.sub.6 and R.sub.7 being alkyl. The novel compound of the general formula ##STR2## where R.sub.5, R.sub.6 and R.sub.7 are as described above is provided and is useful as an intermediate in the preparation of said disazo colorants. Methods for the preparation of the colorants are disclosed together with qualitative and quantitative procedures for detecting these colorants in the marked liquids.

Dependencies are inferred from the claim text.