Title: Yellow OB

CAS Registry Number: 131-79-3

CAS Name: 1-[(2-Methylphenyl)azo]-2-naphthalenamine

Additional Names: C.I. Solvent Yellow 6; 1-o-tolylazo-2-naphthylamine; FD & C Yellow no. 4; Ext. D & C Yellow no. 10; C.I. 11390

Molecular Formula: C17H15N3

Molecular Weight: 261.32

Percent Composition: C 78.13%, H 5.79%, N 16.08%

Literature References: Prepd from diazotized o-toluidine and b-naphthylamine: Krüss, Z. Phys. Chem. 51, 270 (1905); Norman, J. Chem. Soc. 101, 1913 (1912); Fischer, J. Prakt. Chem. 104, 102 (1922); Hodgson, Foster, J. Chem. Soc. 1942, 30. Toxicity studies: Allmark et al., J. Pharm. Pharmacol. 7, 591 (1955); Hansen et al., Toxicol. Appl. Pharmacol. 5, 16 (1963). Formerly used in the U.S. for coloring oleomargarine.

Properties: Deep red crystals from alc. Also reported as bright yellow needles (Krüss). mp 125-126° (Fischer). Practically insol in water. Sol in alc, ether, benzene, carbon tetrachloride, vegetable oils, glacial acetic acid. An alcoholic soln becomes redder with HCl addition, but is unaltered by NaOH addition.

Melting point: mp 125-126° (Fischer)