Marker dyes from aminobenzoate and aniline derivativese

Abstract

Amino azo dyes as markers for fuel oil were prepared from coupling reaction of diazonium salts of nitroanilines, chloroanilines, toluidines and 2-chloro-4-nitroaniline and aminobenzoates such as ethyl-2-aminobenzoate and hexyl-3-aminobenzoate. Amino azo dyes having nitro group substituted and ortho an para positions except hexyl-3-aminobenzozoate-2-nitrophenyl azo were suitable to use as marker dyes in fuel oil. These markers were detected by extraction with alkaline medium solution, developing the clearly defined color in extracted phase. They may be detected quantitatively as low as 1 to 6 ppm by UV-Visible Spectroscopy and were stable in tagged fuel for at least 3 months.