Title: Orange I
CAS Registry Number: 523-44-4
CAS Name: 4-[(4-Hydroxy-1-naphthalenyl)azo]benzenesulfonic acid monosodium salt
Additional Names: Tropaeolin OOO no. 1; C.I. Acid Orange 20; FD & C Orange I; Ext. D & C Orange 3; C.I. 14600; a-naphthol orange; sodium azo-a-naphtholsulfanilate
Molecular Formula: C16H11N2NaO4S
Molecular Weight: 350.32
Percent Composition: C 54.86%, H 3.16%, N 8.00%, Na 6.56%, O 18.27%, S 9.15%
Literature References: Prepared by coupling diazotized sulfanilic acid with a-naphthol: Colour Index vol. 4 (3rd ed., 1971) p 4065.
Properties: Reddish-brown powder. Sol in water to orange-red soln, in alcohol to orange soln. Acids ppt the aq soln. Sodium hydroxide intensifies the red color of the aq soln. pH: 7.6 brownish-yellow; 8.9 purple. |