Formation of a Blue Adduct between 4-tert-Butyl-1,2-benzoquinone and 4-Amino-N,N-diethylaniline

The reaction of 4-tert-butyl-1,2-benzoquinone (BQ) with 4-amino-N,N-diethylaniline (ADA) produces a stable blue adduct with λmax 625 nm (ϵ 11,120 M−1 cm−1). This makes the reaction a sensitive analytical tool, suitable for the detection and spectrophotometric determination of this quinone even in the presence of biological compounds. The adduct was identified as 3-tert-butyl-4-(4′-diethylamino)-phenylimino-6-hydroxycyclohexa-2,5-dien-1-one.