disodium 3-ethyl 4,5-dihydro-5-oxo-4-[(4-sulphonato-1-naphthyl)azo]-1-(4-sulphonatophenyl)-1H-pyrazole-3-carboxylate

Description

Orange B, a food color additive, is approved by the U.S. Food and Drug Administration, but only for use in hot dog and sausage casings, and only in concentrations <150 ppmw in the finished food. Chemically speaking, Orange B is the disodium salt of 1-(4-sulfophenyl)-3-ethylcarboxy-4-(4-sulfonaphthylazo)-5-hydroxypyrazole.

The Uses of disodium 3-ethyl 4,5-dihydro-5-oxo-4-[(4-sulphonato-1-naphthyl)azo]-1-(4-sulphonatophenyl)-1H-pyrazole-3-carboxylate

In coloring sausage and frankfurter casings.

Preparation

Phenylhydrazine-4-sulfonic acid?and 2-Hydroxymaleic acid?ethyl ester derivatives of the sodium reaction, and partly hydrolysis, lost a ethyl, finally and diazo of 4-Aminonaphthalene-1-sulfonic acid matches.

Safety Profile

: When heated to decomposition emits toxic fumes of SOx.

Properties and Applications

dark orange. The strong sulfuric acid for purple, diluted into red; In strong hydrochloric acid for red; In 10% of sodium hydroxide solution for yellow orange, yellow light is palm diluted.