Calconcarboxylic Acid

Calconecarboxylic Acid; Patton and Reeder’s reagent; 2-hydroxy-1-(2-hydroxy-4-sulfo-1-naphthylazo)naphthalene-3-carboxylic acid; C₂₁H₁₄N₂O₇S = 438.4 (3737-95-9)

Brownish-black powder, slightly soluble in water, very slightly soluble in acetone and in ethanol (96%), sparingly soluble in dilute solutions of sodium hydroxide.