Naphthol AS-D

Preparation

O-Methylaniline and 3-Hydroxy-2-naphthoic acid condensation.

Flammability and Explosibility

Non flammable

Purification Methods

Purify it by recrystallisation from xylene. This gives yellow-green fluorescent solutions at pH 8.2-9.5. [IR: Schnopper et al. Anal Chem 31 1542 1959.] The naphthol AS-D acetate is obtained with AcCl, m 168-169o, and with chloroacetyl chloride naphthol AS-D-chloroacetate is obtained [Moloney et al. J Histochem Cytochem 8 200 1960, Burstone Arch Pathology 63 164 1957]. [Beilstein 12 H 505.]

Properties and Applications

yellowish powder, melting point for 195 ~ 196 ℃. Insoluble in water solution and sodium carbonate, soluble in naphtha. In sodium hydroxide solution for yellow. Sensitive to air. Mainly used for cotton yarns, cotton fabric, PVA, viscose, silk and vinegar fiber dyeing, also can be used for direct printing, the cotton print and dye discharge printing, and can be used as a quick pigment and organic pigments intermediate. The affinity of cotton is low, medium coupled ability.