Urea → 3-Methyl-4-((4-nitrophenyl)azo)benzenamine

Participants

Reaction Steps

Recrystallized 4-nitroaniline (16.5 g, 0.12 mol) was dissolved in 10 N hydrochloric acid (40 ml) at 75° C. The solution was diluted with water (40 ml), poured over ice (100 g), and cooled in an ice bath. Sodium nitrite solution (64.0 ml, 2 M) was added over 5 minutes and the mixture was stirred for 30 minutes. Urea (1.0 g) was added and the mixture was stirred 20 minutes in an ice bath. In a separate beaker distilled m-toluidine (17.1 g, 0.16 mol) was mixed with 5 N hydrochloric acid (40 ml) for 5 minutes at room temperature and then cooled in an ice bath. The diazonium salt solution was added all at once to the m-toluidine hydrochloride suspension. The mixture was stirred occasionally over 2 hours at 0°-5° C. The mixture was basified with saturated potassium carbonate and the resulting solid was washed twice with warm water. Recrystallization of the solid twice from tetrahydrofuran (90 ml) and ethanol (200 ml) gave 4-(4-nitrophenylazo)-3-methylaniline as red needles (8.32 g, 28%): mp 152° C.

Provenance & Evidence