Dinitroaniline

Dinitroanilines are a class of organic compounds based on dinitroaniline, with the chemical formula C₆H₃(NO₂)₂NH₂. Six isomers exist depending on the relative positions of the amino (NH₂) and nitro (NO₂) groups: 2,3-dinitroaniline, 2,4-dinitroaniline, 2,5-dinitroaniline, 2,6-dinitroaniline, 3,4-dinitroaniline, and 3,5-dinitroaniline. An organic compound with a dinitroaniline group is also said to be a dinitroaniline.

Dinitroanilines are intermediates in the preparation of various industrial chemicals including dyes and pesticides.^[1] During World War I, Germany used them as Ersatz high explosives.

There are many dinitroaniline herbicides, beginning with trifluralin in 1964. These are all 2,6-dinitroanilines, and work by inhibiting microtubule formation, have low to moderate human toxicity, high aquatic toxicity and are usually applied pre-emergently, often to control grasses and broad-leafed weeds. They include benfluralin, butralin, chlornidine, dinitramine, dipropalin, ethalfluralin, fluchloralin, isopropalin, methalpropalin, nitralin, nitrofor, oryzalin, pendimethalin, prodiamine, profluralin, and trifluralin. Trifluralin, pendimethalin are the most widely commercially used.

2,4-Dinitroaniline can be prepared by reaction of 1-chloro-2,4-dinitrobenzene with ammonia or by acid hydrolysis of 2,4-dinitroacetanilide.^[2][1]

2,6-Dinitroaniline can be prepared in a multistep process involving nitration and sulfonation of chlorobenzene.^[3]

A characteristic reaction of the dinitroanilines is their reduction, first to the diamine, then to the triamine, and finally to the triaminocyclohexanes. Selective conversion to the diamine can be achieved using sulfide as a reducing agent.^[4]Hydrogenation over nickel or palladium catalysts gives triaminobenzenes. Still further hydrogenation (of the ring) affords the triaminocyclohexanes.

Dinitroanilines can be explosive and flammable when exposed to heat or friction.