Methyl yellow

• Dimethyl
• Methyl yellow
• Butter Yellow
• 4 - (dimethylamino ) azobenzene
• (4- dimethylamino ) -azobenzene
• N, N -dimethyl- 4-( phenylazo ) aniline
• C. I. 11020

Yellow leaves

Fixed

113-117 ° C ( decomposition)

2.96

• Insoluble in water (0.23 mg · l-1 at 25 ° C)
• Soluble in ethanol

Risk

Not set

200 mg · kg -1 ( LD50, rat, oral)

Template: Infobox chemical / molecular formula search available

Butter yellow, or yellow and methyl 4 - (dimethylamino ) azobenzene (IUPAC ), is a yellow azo dye.

Production

They are prepared by diazotization of aniline and subsequent coupling with N, N- dimethylaniline.

Use

Historical

Under the name of butter yellow, the dye was used until about 1938 in Germany and up to about 1943 in Switzerland yellowing of butter and margarine (see Fine ), but was forbidden due to the highly carcinogenic effect.