Dichlorobenzenes

Production of o-dichlorobenzene is around 80,000 tpa. The largest producers are the United States, Japan and West Germany. 

Another herbicide based on 3,4-dichloroaniline, produced in similar quantities, is diuron Du Pont), which can be obtained by the reaction of 3,4-dichloroaniline, urea and dimethylamine accompanied by the liberation of ammonia. 

4-Dichloroaniline and propionic acid react together in the presence of thionyl chloride to yield propanil, a herbicide introduced by Rohm Haas. 

The reaction of 3,4-dichloronitrobenzene with KF in aprotic solvents such as sulfolane gives 3-chloro-4-fluoronitrobenzene, which is converted into the Shell herbicide flamprop-methyl by reduction, reaction with chloropropionic acid, esterification and subsequent acylation with benzoyl chloride. 

Polyphenylene sulfide is used in the manufacture of thermoplastic resins, which are marked by high long-term temperature stability (260 °C) and good chemical resistance (Phillips Petroleum, USA Kureha, Japan). 

---

Two other types of equilibrium curves are occasionally encountered with the system of two components forming a continuous series of solid solutions. These are shown in Figs. 1,16, 3 and 1,16, 4. In the former the freezing or melting curve passes through a minimum (examples p-chloroiodobenzene, m.p. 57° - p-dichlorobenzene, m.p. 53° naphtha-... 

The observation of nitration in nitromethane fully dependent on the first power of the concentration of aromatic was made later. The rate of reaction of /)-dichlorobenzene ([aromatic] = 0-2 mol [HNO3] = 8-5 mol 1 ) obeyed such a law. The fact that in a similar solution 1,2,4-trichlorobenzene underwent reaction according to the same kinetic law, but about ten times slower, shows that under first-order conditions the rate of reaction depends on the reactivity of the compound. 

In acetic acid the rates of nitration of chlorobenzene and bromo-benzene were fairly close to being first order in the concentration of aromatic, and nitration fully according to a first-order law was observed with O, m-, and/i-dichlorobenzene, ethyl benzoate and 1,2,4-trichloro-benzene. 

Using the partial rate factors for nitration of chlorobenzene, Ridd and de la Mare calculated the relative rates of nitration of the dichlorobenzenes, with respect to /)-dichlorobenzene, with the results shown below. Also given are results based on more recent nitrations in mixed... 

Which one of the dichlorobenzene isomers does not have a dipole moment" Which one has the largest dipole moment" Compare your answers with the dipole moments calculated using the molecular modeling software in Learning By Modeling... 

From among the compounds chlorobenzene o dichlorobenzene and p dichlorobenzene choose the one that... 

---