2.6- Dinitroanilines

The development of this group of selective herbicides began in the research laboratories of the Eli Lilly and Co., Alder and Bevington 1962 and Alder et al. 

The unsubstituted 2,6-dinitroaniline molecule has virtually no biological activity, but derivatives substituted in the nucleus and at the N atom exhibit herbicidal activity Wilder, 1969). 

The general formula of dinitroaniline derivatives with herbicidal properties is the following  

The more important dinitroaniline derivatives known today are N,N-bis(2-chloroethyl)-4-trifluoromethyl-2,6-dinitroaniline (BAS 3870 H, 1) N-butyl-N-ethyl-a,a,a-trifluoro-2,6-dinitro-p-toluidide (benfluralin, 2) N-jec-butyl-4-r-butyl- 

6- dinitroaniline (chlomidine, 5) N, N -diethyl-2,6-dinitro-4-trifluoromethyl-w-phenylenediamine(dinitramine, 6) N,N-dipropyl-2,6-dinitro-4-methylaniline (di-propalin, 7) N-ethyl-N-(2-methylallyl)-2,6-dinitro-4-trifluoromethylaniline (ethal-fluralin, 8) N-(2-chloroethyl)-N-propyl-2,6-dinitro-4-trifluoromethylaniline (fluch-loralin, 9) 4-isopropyl-2,6-dinitro-N,N-dipropylaniline (isopropalin, 10)  

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Dinitroaniline. This preparation is another illustration of the mobile character of the chlorine atom in 2 4-dinitro-l-chlorobenzene ... 

Dinitroaniline from 3 5-dinItrobenzoic acid. Place a solution of 50 g. of 3 5-dinitrobenzoic acid (Section IV, 168) in 90 ml. of 10 per cent, oleum and 20 ml. of concentrated sulphuric acid in a 1-litre three necked flask equipped with a reflux condenser, mechanical stirrer, adropping funnel, and thermometer (FUME CUPBOARD ). Add 100 ml. of clJoroform and raise the temperature to 45°. Stir rapidly and add 17 -5g. of sodium azide in small portions whilst maintaining the temperature at 35-45°. The reaction is accompanied hy foaming, which usually commences after about 3 g. of sodium azide has been introduced. After all the sodium azide has been added raise the temperature so that the chloroform refluxes vigorously and maintain this temperature for 3 hours. Then cool the reaction mixture, pour it cautiously on to 500 g. of crushed ice, and dilute with 3 litres of water. After 1 hour, separate the yellow solid by filtration at the pump, wash well with water and dry at 100°. The yield of 3 5-dinitroaniline, m.p. 162-163°, is 39 g. The m.p. is unaffected by recrystallisation from dilute alcohol. 

The operation of the nitronium ion in these media was later proved conclusively. "- The rates of nitration of 2-phenylethanesulphonate anion ([Aromatic] < c. 0-5 mol l i), toluene-(U-sulphonate anion, p-nitrophenol, A(-methyl-2,4-dinitroaniline and A(-methyl-iV,2,4-trinitro-aniline in aqueous solutions of nitric acid depend on the first power of the concentration of the aromatic. The dependence on acidity of the rate of 0-exchange between nitric acid and water was measured, " and formal first-order rate constants for oxygen exchange were defined by dividing the rates of exchange by the concentration of water. Comparison of these constants with the corresponding results for the reactions of the aromatic compounds yielded the scale of relative reactivities sho-wn in table 2.1. 

Thermal—Oxidative-Resistance Coatings. The thermal stabihty of coatings produced by either covalendy or noncovalendy incorporating 2,4-dinitroaniline into an inorganic siUcate network and coating it onto a sapphire substrate has been examined (67). Although some increase in the thermal... 

DCPA inhibits the growth of grass species by dismpting the mitotic sequence, probably at entry (190). DCPA influences spindle formation and function (181) and causes root-tip swelling (182) and britde shoot tissue (191). It has been reported that DCPA, like colchicine and vinblastine, attests mitosis at prometaphase and is associated with formation of polymorphic nuclei after mitotic arrest (192). Pronamide also inhibits root growth by dismpting the mitotic sequence in a manner similar to the effect of colchicine and the dinitroanilines (193,194). Cinmethylin and bensuhde prevent mitotic entry by unknown mechanisms (194). 

Considerable research has been conducted to investigate the soil sorption and mobiUty of dinitroaniline herbicides. In general, these herbicides are strongly sorbed by soil (354), and sorption has been correlated to both soil organic matter and clay content (355). Dinitroaniline herbicides are not readily leached in most soils (356), although leaching of triduralin is enhanced by addition of surfactants (357). 

Health advisories have been issued for the phenol dinoseb and trifiuralin health advisories have not been issued for the remaining dinitroaniline herbicides, eg, profluralin [26399-36-0]. 

Pigment Orange 5 [3468-63-1] 12075 monoa2o (Dinitraniline Orange) coupling of dia2oti2ed 2,4-dinitroaniline with 2-naphthol... 

Blues are the single most important color in the disperse class, both in terms of amounts produced and doUar sales volume. Among all dyes. Disperse Blue 79 (100) (6-bromo-2,4-dinitroaniline [1817-73-8] coupled to 3-bis-(2-acetoxyethyl)-amino-/)-acetophenetidine [20249-05-2]) was the highest volume dye in the late 1980s and continues. As reported in 1985, the United States produced 2872 tons valued at 7.7 million. 

Odier bromine-containing dye intemiediates include 6-bromo-2,4-dinitroaniline [1817-73-8] C H BrN O, and 5,7-dibromoisatin [6374-91-0] CgH2Bi2N02. Bromodinitroaniline is used in making a2o dyes and dibromoisatin is used in making Alizarin Indigos B, 3R, and G. 

The 0- and -monochloro- and 2,4- and 3,4-dichlorobenzotrichlorides are iatermediates ia the manufacture of the corresponding chlotinated benzoic acids and benzoyl chlorides. Fluotination of the chlotinated benzotrichlorides produces the chlotinated benzotrifluorides, iatermediates ia the manufacture of dinitroaniline and diphenyl ether herbicides (76). 

Dinitroaniline [97-02-9] M 183.1, m 180 , 8349 12,300 in dil aq HCIO4, pK -4.27 (aq H2SO4). Crystd from boiling EtOH by adding one-third volume of water and cooling slowly. Dried in a steam oven. 

Dinitroaniline [606-22-4] M 183.1, m 139-140 , pK -5.37 (aq H2SO4). Purified by chromatography on alumina, then crystd from benzene or EtOH. 

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