5928. Metanil Yellow

Nomenclature

CAS number: 587-98-4
3-[[4-(Phenylamino)phenyl]azo]benzenesulfonic acid monosodium salt; C.I. Acid Yellow 36; m-[(p-anilinophenyl)azo]benzenesulfonic acid sodium salt; sodium salt of metanilylazodiphenylamine; Ext. D & C Yellow No. 1; C.I. 13065; Tropaeolin G.
C18H14N3NaO3S; mol wt 375.38.
C 57.59%, H 3.76%, N 11.19%, Na 6.12%, O 12.79%, S 8.54%.

Description and references

Prepn: Welcher, Organic Analytical Reagents vol. 4 (Van Nostrand, 1948) p 516; Colour Index vol. 4 (3rd ed., 1971) p 4045.

Chemical structure

Properties

Brownish-yellow powder. Sol in water, alc; moderately sol in benzene, ether; slightly sol in acetone.

Use

As indicator in 0.1% soln, of which 2 drops are required for 10 ml liquid. pH: 1.2 red to 2.3 yellow.