https://www.selleckchem.com/products/SP600125.html
A method for increasing the solubilities of industrial azo pigments in DMSO by adding DBU (1,8-diaza-7-bicyclo[5.4.0]undecene) has been developed. This facilitated the acquisition of solution 13 C NMR spectra of the pigments. This method was applied to four types of azo pigments naphthol AS (3-hydroxy-2-naphthoic acid anilide) pigments, naphthol pigments, pyrazolone pigments and acetoacetanilide pigments. This represents the first solution 13 C NMR spectra for naphthol AS pigments. Altogether 18 industrial azo pigments were analysed us