Title: Polar® Yellow (Ciba)
CAS Registry Number: 6372-96-9
CAS Name: 5-Chloro-2-[4,5-dihydro-3-methyl-4-[[4-[[(4-methylphenyl)sulfonyl]oxy]phenyl]azo]-5-oxo-1H-pyrazol-1-yl]benzenesulfonic acid monosodium salt
Additional Names: 4-p-hydroxybenzeneazo-1-p-chloro-o-sulfophenyl-3-methyl-5-hydroxypyrazole toluene-p-sulfonyl ester sodium salt; C.I. Acid Yellow 40; C.I. 18950
Molecular Formula: C23H18ClN4NaO7S2
Molecular Weight: 584.98
Percent Composition: C 47.22%, H 3.10%, Cl 6.06%, N 9.58%, Na 3.93%, O 19.15%, S 10.96%
Literature References: Prepn from diazotized p-aminophenol and 1-(o-sulfo-p-chlorophenyl)-3-methyl-5-pyrazolone: B. Richard, US 1067881 (Geigy). See also: Colour Index vol. 4 (3rd ed., 1971) p 4128.
Properties: Yellowish-brown powder. Sol in water giving a pure yellow soln; in alcohol (yellow color); in alkalies; in concd sulfuric acid. Slightly sol in ethanol, acetone. Insol in other org solvents. Precipitated by dil acids.
Use: To dye wool. In the isoln of polymyxin. |