(a)?3,4,5-Trihydroxy-N-phenylbenzamide and 3,4,5-Trihydroxybenzoic acid or its derivatives (DE80434) reaction; (b)3,4,5-Trihydroxybenzamide (DE 118393) sulfonamide technology and oxidation.
Properties and Applications
dark blue purple. Soluble in water is blue; In concentrated sulfuric acid for purple; After dilution for red light purple to wine red, adding sodium hydroxide in aqueous solution is purple.
