Chloro-aromatic compounds of the formula ##STR1## wherein R is CF.sub.3, OCF.sub.3, OC.sub.2 F.sub.5, CN, NCO, or COCl, m is 0, 1 or 2; n is 0, 1 or 2; q is 1 or 2; q+m+n is less than 6; and when q is 1, m is 2; are prepared by the vapor phase chloro-denitration reaction of a chlorinating agent with a nitro-aromatic compound of the formula ##STR2## where R, m, n and q are as defined above.

This invention relates to a vapor-phase chloro-denitration process for the 
preparation of nuclear-chlorinated aromatic compounds including aromatic 
compounds bearing both chlorine and fluorine substituents on an aromatic 
ring and to novel compounds prepared thereby. The chloro- and 
chloro-fluoro aromatic compounds prepared by the process of this invention 
are especially useful as chemical intermediates for a variety of useful 
chemical products. 
The preparation of chlorobenzene compounds by chlorodenitration of the 
corresponding nitrobenzene compounds in the liquid phase is known. For 
example, the liquid phase chlorodenitration of 2-nitrobenzonitriles to 
form the corresponding 2-chlorobenzonitriles is disclosed in U.S. Pat. No. 
4,225,534. Furthermore, it is known from the chemical literature that 
certain nitrobenzene or fluoronitrobenzene compounds may react with 
chlorine in the vapor phase with the replacement of nitro groups by 
chlorine atoms. (Vorozhtsov et all, Zhurnal Obshchei Khimii, Vol. 31, No. 
4, pp. 1222-1226, April 1961). Such vapor phase reactions have been shown 
to be feasible only with certain unsubstituted nitrobenzenes or 
fluoronitrobenzenes. However, it has not heretofore been known suggested 
that other substituted nitrobenzenes or substituted fluoronitrobenzenes 
might undergo chlorodenitration by vapor phase reaction with chlorine. 
Some of the dihalo and trihalo compounds that may be prepared by the 
process of this invention, including aromatic compounds having both chloro 
and fluoro substituents on the aromatic ring, have been prepared by 
various prior art methods. U.S. Pat. No. 4,388,472 discloses the 
preparation of 3,4,5-trichlorobenzotrifluoride from 
2,6-dichloro-4-trifluoromethylaniline by diazotization followed by 
reaction with cuprous chloride in concentrated hydrochloric acid. The 
3,4,5-trichlorobenzotrifluoride product may then be reacted with KF to 
form 3-chloro-4,5-difluorobenzotrifluoride. U.S. Pat. No. 4,259,510 
discloses the preparation of trifluoromethylphenyl nitrophenylethers 
utilizing phenol reactants which may be prepared from substituted 
halobenzene reactants, including dihalobenzotrifluorides. U.S. Pat. No. 
4,012,453 discloses a catalyzed oxychlorofluorination reaction of toluene, 
benzotrichloride, hydrogen fluoride and oxygen wherein the product 
includes chlorofluorobenzotrifluoride as a component. The preparation of 
4-chloro-3-fluorobenzotrifluoride by diazotiation of 
3-amino-4-chlorobenzotrifluoride, isolating the diazonium salt as the 
fluoroborate then decomposing the salt is disclosed in European Pat. No. 0 
023 392 to Cartwright et al. In addition, the incidental preparation of a 
chlorofluorobenzotrifluoride is described in Feast et al in J. Chem. Soc. 
(c), 1971, 1547-49. The reference discloses 
4-chloro-3-fluorobenzotrifluoride as a minor co-product obtained during 
the synthesis of 3,4-difluorobenzotrifluoride 
from3-amino-4-fluorobenzotrifluoride. 
SUMMARY OF THE INVENTION 
It has now been found that substituted chloro-aromatic compounds of the 
formula 
##STR3## 
wherein m is 0, 1 or 2, n is 0, 1 or 2, q is 1 or 2, q+m+n is less than 6, 
and when q is 1, m is 2, R is CF.sub.3 ; OCF.sub.3, OC.sub.2 F.sub.5, CN, 
NCO, or COCl, may be prepared by the vapor phase reaction of a 
chlorinating agent with a substituted nitroaromatic compound of the 
formula 
##STR4## 
where m, n, q, and R are as defined above. 
The chloro-denitration process of this invention is carried out under 
conditions of temperature and pressure appropriate for a vapor phase 
reaction, the exact conditions being dependent on the properties of the 
particular reactants employed. Typically, the process is carried out at 
atmospheric conditions and at a temperature in the range of about 
200.degree. to about 450.degree. Celsius, or higher, preferably about 
250.degree. to 450.degree. C. and most preferably 290.degree. to 
410.degree. C. 
The preferred chlorinating agent for economic considerations as well as 
efficiency of reaction, is chlorine. However, other chlorinating agents, 
including for example, hydrogen chloride gas, thionyl chloride, sulfuryl 
chloride, sulfur chloride, phosgene, phosphorus trichloride, may be 
employed if desired. 
The proportions of reactants may vary widely with no critical limits. 
However, since chlorine is generally the less costly of the reactants, it 
is recommended to employ chlorine in excess of the amount necessary to 
react with the aromatic --NO.sub.2 groups(s). For example, a molar ratio 
of Cl.sub.2 :NO.sub.2 --of about 1.1:1 to about 10:1, is preferred. 
The process of the invention is useful for the preparation of various 
specific unfluorinated or mono- or di-fluorinated, mono-, di, and 
tri-chloro-substituted benzotrifluorides, benzoyl chlorides, phenyl 
isocyanates, and benzonitriles, trifluoromethoxy-benzenes, and 
pentafluoroethoxybenzenes. 
Typical of the chloro-substituted benzotrifluorides that may be prepared by 
the chloro-denitration process of this invention are 
2-chlorobenzotrifluoride; 3-chlorobenzotrifluoride; 
4-chlorobenzotrifluoride; 3-chloro-4-fluorobenzotrifluoride; 
4-chloro-3-fluorobenzotrifluoride; 2-chloro-5-fluorobenzotrifluoride; 
5-chloro-2-fluorobenzotrifluoride; 2-chloro-4-fluoro-benzotrifluoride; 
4-chloro-2-fluorobenzotrifluoride; 3-chloro-5-fluorobenzotrifluoride; 
2,5-dichloro-4-fluorobenzotrifluoride; 
4,5-dichloride-2-fluorobenzotrifluoride; 
3,5-dichloro-4-fluorobenzotrifluoride; 
3,4-difluoro-5-chlorobenzotrifluoride; 
2,5-difluoro-3-chlorobenzotrifluoride; 
3,5-difluoro-4-chlorobenzotrifluoride; 3,4-5-trichlorobenzotrifluoride; 
and the like. Typical of the chloro-substituted benzoyl chlorides that may 
be prepared are 2-chlorobenzoyl chloride; 3-chlorobenzoyl chloride; 
4-chlorobenzoyl chloride; 4-chloro-3-fluorobenzoyl chloride; 
3-chloro-4-fluorobenzoyl chloride; 2-chloro-4-fluorobenzoyl chloride; 
4-chloro-2-fluorobenzoyl chloride; 2-chloro-5-fluorobenzoyl chloride; 
5-chloro-2-fluorobenzoyl chloride; 3-chloro-5-fluorobenzoyl chloride; 
2,5-dichloro-4-fluorobenzoyl chloride; 3,5-dichloro-4-fluorobenzoyl 
chloride; 4,5-dichloro-2-fluorobenzoyl chloride; 
3,4-difluoro-5-chlorobenzoyl chloride; 3,5-difluoro-4-chlorobenzoyl 
choride; 3,4,5-trichlorobenzoyl chloride; and the like. Typical of the 
chloro-substituted trifluoromethoxybenzenes that may be prepared are 
2-chlorotrifluoromethoxybenzene; 3-chlorotrifluoromethoxybenzene; 
4-chlorotrifluoromethoxy benzene; 
3-chloro-4-fluorotrifluoromethoxybenzene; 2-chloro-4-fluorotrifluoromethox 
ybenzene; 4-chloro-2-fluorotrifluoromethoxybenzene; 
2-chloro-5-fluorotrifluoromethoxybenzene; 
5-chloro-2-fluorotrifluoromethyoxybenzene; 
3-chloro-5-fluorotrifluoromethoxybenzene; 
2,5-dichloro-4-fluorotrifluoromethoxybenzene; 
4,5-dichloro-2-fluorotrifluoromethoxybenzene; 
3,5-dichloro-4-fluoromethoxybenzene; 3,4-difluoro- 
5-chlorotrifluoromethoxybenzene; 
2,5-dlifluoro-3-chlorotrifluoromethoxybenzene; 
3,5-difluoro-4-chlorotrifluoromethoxybenzene; 
3,4,5-trichloro-trifluoromethoxybenzene; and the like. Typical 
chloro-substituted pentafluoroethoxybenzenes that may be prepared are 
2-chloropentafluoroethoxybenzene; 3-chloro-pentafluoroethoxybenzene; 
4-chloro-pentafluoroethoxybenzene; 
2-chloro-5-fluoro-pentafluoroethoxybenzene; 
5-chloro-2-fluoro-pentafluoroethoxybenzene; 
3-chloro-4-fluoro-pentafluoroethoxybenzene; 
4-chloro-3-fluoro-pentafluoroethoxybenzene; 
2-chloro-4-fluoropentafluoroethoxybenzene; 
4-chloro-2-fluoro-pentafluoroethoxybenzene; 
3-chloro-5-fluoro-pentafluoroethoxybenzene; 
2,5-dichloro-4-fluoro-pentafluoroethoxybenzene; 
4,5-dichloro-2-fluoro-pentafluoroethoxybenzene; 
3,5-dichloro-4-fluoro-pentafluoroethoxybenzene; 
3,4-difluoro-5-chloro-pentafluoroethoxybenzene; 
2,5-difluoro-3-chloro-pentafluoroethoxybenzene; 
3,5-difluoro-4-chloro-pentafluoroethoxybenzene; 
3,4,5-trichloro-pentafluoroethoxybenzene; and the like. Typical 
chloro-substituted benzonitriles that may be prepared are 
2-chlorobenzonitrile; 3-chlorobenzonitrile; 4-chlorobenzobenzonitrile; 
2-chloro-5-fluorobenzonitrile; 5-chloro-2-fluorobenzonitrile; 
3-chloro-4-fluorobenzonitrile; 4-chloro-3-fluorobenzonitrile; 
2-chloro-4-fluorobenzonitrile; 4-chloro-2-fluorobenzonitrile; 
3-chloro-5-fluorobenzonitrile; 2,5-dichloro-4-fluorobenzonitrile; 
4,5-dichloro-2-fluorobenzonitrile; 3,5-dichloro-4-fluorobenzonitrile; 
3,4-difluoro-5-chlorobenzonitrile; 2,5-difluoro-3-chlorobenzonitrile; 
3,5-difluoro-4-chlorobenzonitrile; 3,4,5-trichlorobenzonitrile; and the 
like. Typical chloro-substituted phenyl isocyanates that may be prepared 
are 2-chlorophenyl isocyanate; 3-chlorophenyl isocyanate; 4-chlorophenyl 
isocyanate; 2 -chloro-5-fluorophenyl isocyanate; 5-chloro-2-fluorophenyl 
isocyanate; 3-chloro-4-fluorophenyl isocyanate; 4-chloro-3-fluorophenyl 
isocyanate; 2-chloro-4-fluorophenyl isocyanate; 4-chloro-2-fluorophenyl 
isocyanate; 3-chloro-5-fluorophenyl isocyanate; 
2,5-dichloro-4-fluorophenyl isocyanate; 4,5-dichloro-2-fluorophenyl 
isocyanate; 3,5-dichloro-4-fluorophenyl isocyanate; 
3,4-difluoro-5-chlorophenyl isocyanate; 2,5-difluoro-3-chlorophenyl 
isocyanate; 3,5-difluoro-4-chlorophenyl isocyanate; 3,4,5-trichlorophenyl 
isocyanate; and the like. 
The process of the invention is particularly useful for the preparation of 
a wide variety of specific useful chemical intermediates in substantially 
pure form, heretofore unavailable to the chemical industry. The 
chloro-fluoro-aromatic compounds, prepared by the process of this 
invention are particulary useful for various organic syntheses based on 
nucleophilic substitution at the fluorine site. Thus, for example, the 
novel compound 5-chloro-2-fluorobenzotrifluoride may be reacted with an 
alkali metal hydroxide, such as potassium hydroxide, to produce 
4-chloro-2-trifluoromethylphenol. Similarly, 
2-chloro-4-trifluoromethylphenol, may be prepared by reaction of 
3-chloro-4-fluorobenzotrifluoride with an alkali metal hydroxide, such as 
potassium hydroxide. Because of the higher reactivity of the nuclear 
fluorine, the reactants can be run under mild conditions to afford a high 
yield of the desired product with little or no formation of undesired 
isomers. The resultant chloro-trifluoromethylphenolate may be acidified to 
form the corresponding phenol compound. One method for the preparation of 
such compounds, as well as their use in the further preparation of various 
diphenyl ether herbicides is disclosed in detail in U.S. Pat. Nos. 
4,262,152 and 4,259,510. 
This novel compound 2,5-dichloro-4-fluorobenzotrifluoride may be reacted 
with hydroquinone, or a substituted phenol under basic conditions to form 
a phenyl ether of the type disclosed in U.S. Pat. No. 4,200,587 (compound 
V, Col. 4). As disclosed therein, such phenyl ethers may be further 
reacted with a suitable oxime to form useful herbicides. 
The novel compound 2-chloro-5-fluorobenzotrifluoride may be similarly 
reacted with potassium hydroxide to produce the 
4-chloro-3-trifluoromethylphenolate which may then be acidified to form 
the corresponding phenol compound. Upon hydrogenolysis, the 
4-chloro-3-trifluoromethylphenol may be converted to 
3-trifluoro-methylphenol. The use of this compound in the further 
preparation of pharmaceuticals is disclosed in detail in U.S. Pat. Nos. 
4,168,388 and 4,018,895. 
The chloro-denitration process of this invention may, in some instances, be 
utilized with different reactants to produce the same end product. Thus, 
for example, the compound 3,4,5-trichlorobenzotrifluoride, a known and 
useful chemical intermediate, may be prepared in accordance with this 
invention, by chloro-denitration of 3,4-dichloro-5-nitrobenzotrifluoride. 
Alternatively, 3,4,5-trichlorobenzotrifluoride may be prepared, in 
accordance with this invention, by chlorodenitration of 
4-chloro-3,5-dinitrobenzotrifluoride. The latter compound, 
4-chloro-3,5-denitrobenzotrifluoride, is also a useful starting reactant 
for the preparation of a novel intermediate that may also be 
chloro-denitrated in accordance with this invention. Thus, for example, 
4-chloro-3,5-dinitrobenzotrifluoride may be reacted with an alkali metal 
fluoride to form a novel intermediate, 
3,4-difluoro-5-nitrobenzotrifluoride, which may in turn, be converted, by 
chloro-denitration in accordance with this invention, to 
3-chloro-4,5-difluorobenzofluoride, a known and useful compound. Moreover, 
the reactant 3,4-dichloro-5-nitrobenzotrifluoride is also useful as a 
starting reactant for the preparation of a novel intermediate that may be 
chloro-denitrated in accordance with this invention. Thus, 
3,4-dichloro-5-nitrobenzotrifluoride may be reacted with an alkali metal 
fluoride to form a novel intermediate, 
3-chloro-4-fluoro-5-nitrobenzotrifluoride, which in turn, may be converted 
by chloro-denitration, in accordance with this invention, to 
3,5-dichloro-4-fluorobenzotrifluoride.

The following specific examples are provided to further illustrate this 
invention and the manner in which it may be carried out. It will be 
understood, however, that the specific details given in the examples have 
been chosen for purpose of illustration and are not to be construed as a 
limitation on the invention. In the examples, unless otherwise indicated, 
all parts and percentages are by weight and all temperatures are in 
degrees Celsius. 
EXAMPLE 1 
A solution of 5.3 parts of 2-nitrobenzonitrile in 37 parts of chloroform 
was introduced concurrently with chlorine at a Cl.sub.2 :nitrobenzonitrile 
molar ratio of 10:1 into a vapor phase reactor at a temperature of 
390.degree.-400.degree. C. The reaction product was condensed, and 
collected. Analysis by gas chromatographic and mass spectrum techniques 
indicated 2-chlorobenzonitrile as the main product. 
EXAMPLE 2 
The procedure of Example 1 was repeated except that in place of 5.3 parts 
of 2-nitrobenzonitrile there was substituted 40 parts of 
3-nitrobenzonitrile. The structure of the product 3-chlorobenzonitrile was 
confirmed by gas chromatography-mass spectrum and nuclear magnetic 
resonance analyses. 
EXAMPLE 4 
Chlorine and 4-nitrobenzoyl chloride (as a solution of 4.4 parts in 37 
parts of carbon tetrachloride) were introduced simultaneously (at a 10:1 
mol ratio of Cl.sub.2 :nitrobenzoyl chloride) into a vapor phase reactor 
maintained at a temperature of 340.degree. to 360.degree. C. The reaction 
product was condensed and collected. Analysis by gas chromatographic-mass 
spectrum and nuclear magnetic resonance techniques confirmed the main 
product as 4-chlorobenzoyl chloride. 
EXAMPLE 5 
The procedure of Example 4 was repeated except that 3-nitrobenzoyl chloride 
(5.7 parts dissolved in 1.5 parts of carbon tetrachloride) was employed in 
place of 4-nitrobenzoyl chloride to yield a reaction product containing 
3-chlorobenzoyl chloride as the major component. The structure of the 
3-chlorobenzoyl chloride product was confirmed by gas chromatographic-mass 
spectrum and nuclear magnetic resonance analyses. 
EXAMPLE 6 
Chlorine and p-nitrotrifluoromethoxybenzene (10.7 parts) were fed 
simultaneously at a molar ratio of 3:1, Cl.sub.2 :organic reactant, into a 
vapor phase reactor maintained at 300.degree. to 320.degree. C. over a 30 
minute period to yield 8.2 parts of p-chlorotrifluoromethoxybenzene (83% 
yield). The structure of the product was confirmed by gas 
chromatographic-mass spectrum and F.sup.19 nuclear magnetic resonance 
analysis. 
EXAMPLE 7 
Chlorine and 3-fluoro-2-nitrophenyl isocyanate (4.1 parts dissolved in 24 
parts of carbon tetrachloride) were introduced simultaneously (Cl.sub.2 
:organic reactant, 10:1) into a vapor phase reactor maintained at about 
310.degree. C. Analysis of the reaction product by gas chromatographic 
mass spectrum at F.sup.19 nuclear magnetic resonance techniques indicated 
3-fluoro-2-chlorophenyl isocyanate as the major component. 
EXAMPLE 8 
In a continuous process, about 14 parts per hour of 
2-fluoro-5-nitrobenzotrifluoride vapors and about 12 parts per hour of 
chlorine gas were passed simultaneously through a vapor phase reactor 
maintained at a temperature of about 320.degree. to 380.degree. C. The 
vaporized reaction product was condensed and collected. The process was 
continued until about 20 parts of 2-fluoro-5-nitrobenzotrifluoride and 
about 17.3 parts of chlorine gas had been passed through the reactor. 
Analysis of the reaction product indicated 16.7 parts of 
5-chloro-2-fluorobenzotrifluoride, a yield of 89%. The structure of the 
product was confirmed by gas chromatography-mass spectrum F.sup.19 and 
C.sup.13 nuclear magnetic resonance analysis. 
EXAMPLE 9 
14.1 parts of 5-fluoro-2-nitrobenzotrifluoride vapors and 12.1 parts of 
chlorine gas were passed simultaneously, over a one hour period, through a 
vapor-phase reactor maintained at a temperature of about 320.degree. to 
380.degree. C. The vaporized reaction product was condensed and collected. 
Analysis of the reaction product indicated 12.6 parts of 
2-chloro-5-fluorobenzotrifluoride, a yield of 94%. The structure of the 
product was confirmed by gas chromatography-mass spectrum F.sup.19 and 
C.sup.13 nuclear magnetic resonance analysis. 
EXAMPLE 10 
In a continuous process, about 8 parts per hour of 
4-fluoro-3-nitrobenzotrifluoride vapors and about 15 parts per hour of 
chlorine gas were passed simultaneously through a vapor phase reactor 
maintained at a temperature of about 320.degree. C. and the reaction 
product vapors were condensed and collected. The process was continued 
until about 40 parts of 4-fluoro-3-nitrobenzotrifluoride had been passed 
through the reactor, yielding about 36.3 parts of 
3-chloro-4-fluorobenzotrifluoride product. The structure of the product 
was confirmed by spectral analysis. 
EXAMPLE 11(A) 
About 500 parts of aqueous nitric acid was added slowly, with stirring, to 
a reaction vessel containing about 400 parts of 
3-chloro-4-fluorobenzotrifluoride. The temperature of the reaction mixture 
was maintained at about 40.degree. C. during the addition, then raised to 
about 60.degree. C. and maintained thereat for about 5 hours. The reaction 
mixture was allowed to settle. The aqueous layer was removed and the 
organic layer was washed twice with 500 parts of water, treated several 
times with a saturated solution of sodium bicarbonate, washed with water 
again, dried over anhydrous magnesium sulfate, and filtered. The filtrate 
was distilled at reduced pressure to yield 347 parts of 
5-chloro-4-fluoro-2-nitrobenzotrifluoride. 
EXAMPLE 11(B) 
In a continuous process, about 14 parts per hour of 
5-chloro-4-fluoro-2-nitrobenzotrifluoride vapors and about 12 parts per 
hour of chlorine gas were passed simultaneously through a vapor phase 
reactor maintained at a temperature of about 320.degree. to 380.degree. C. 
The vaporized reaction product was condensed and collected. The process 
was continued until about 14.7 parts of 
5-chloro-4-fluoro-2-nitrobenzotrifluoride had been added and 14.7 parts of 
2,5-dichloro-4-fluorobenzotrifluoride product was collected. The structure 
of the product was confirmed by gas chromatography-mass spectrum, F.sup.19 
and C.sup.13 nuclear magnetic resonance analylsis. 
The novel chlorofluorobenzotrifluorides of Examples 8-11 are particularly 
useful as intermediates for use in various organic syntheses based on 
nucleophilic aromatic substitution at the fluorine site. Examples 12-14 
are typical of such syntheses. 
EXAMPLE 12 
Approximately 20 parts of 5-chloro-2-fluorobenzotrifluoride is reacted with 
14 parts of powdered potassium hydroxide (85%) in dimethylsulfoxide 
solvent at a temperature of about 60.degree.-70.degree. C. for 12 to 16 
hours to form 4-chloro-3-trifluoromethylphenolate. The concentrated 
product is mixed with ethanol solvent and reacted with hydrogen under 
basic conditions, in the presence of a noble metal catalyst to form 
m-hydroxybenzotrifluoride, a known and useful chemical intermediate. 
EXAMPLE 13 
Approximately 20 parts of 2-chloro-5-fluorobenzotrifluoride is reacted with 
14 parts of powdered potassium hydroxide (85%) in dimethylsulfoxide 
solvent at a temperature of about 60.degree.-70.degree. C. for 12 to 16 
hours to form 4-chloro-3-trifluoromethylphenolate. The reaction mixture is 
cooled, poured into iced water, and acidified with concentrated 
hydrochloric acid. The aqueous mixture is then extracted with methylene 
chloride and the organic layer dried and concentrated to recover 
4-chloro-3-trifluoromethylphenol. The concentrated product is mixed with 
ethanol solvent and reacted with hydrogen under basic conditions, in the 
presence of a nobel metal catalyst to form m-hydroxybenzotrifluoride, a 
known and useful chemical intermediate. 
EXAMPLE 14 
Approximately 20 parts of 3-chloro-4-fluorobenzotrifluoride is reacted with 
14 parts of powdered potassium hydroxide (85%) in dimethylsulfoxide 
solvent at a temperature of about 60.degree.-70.degree. C. for 12 to 16 
hours to form 2-chloro-4-trifluoromethylphenolate. The reaction mixture is 
cooled, poured into iced water, and acidified with concentrated 
hydrochloric acid. The aqueous mixture is then extracted with methylene 
chloride and the organic layer dried and concentrated to recover 
2-chloro-4-trifluoromethylphenol. 
EXAMPLE 15 
(A) In a continuous process, about 32 parts per hour of 
3,4-difluoro-5-nitrobenzotrifluoride vapors and about 30 parts per hour of 
chlorine gas were passed simultaneously through a vapor phase reactor 
maintained at a temperature of about 300.degree. to 350.degree. C. The 
vaporized reaction product was condensed and collected. The process was 
continued until about 9.5 parts of 3,4-difluoro-5-nitrobenzotrifluoride 
and about 10 parts of chloride gas had been passed through the reactor. 
Analysis of the reaction product indicated 6 parts of 
3-chloro-4,5-difluorobenzotrifluoride, a yield of 66%. The structure of 
the product was confirmed by gas chromatography-mass spectrum analysis. 
(B) The 3,4-difluoro-5-nitrobenzotrifluoride starting material used in the 
above example was prepared as follows: a mixture of 5.4 parts of 
4-chloro-3,5-dinitrobenzotrifluoride and 7.0 parts of anhydrous potassium 
fluoride in 10.0 parts of dimethylformamide, was heated to about 
155.degree. C. under a nitrogen atmosphere, and maintained thereat for 
about one hour. The reaction product was extracted with diethyl ether and 
dried to yield 1.74 parts of crude 3,4-difluoro-5-nitrobenzotrifluoride 
(38.4% yield). The structure of the product was confirmed by spectral 
analysis. 
EXAMPLE 16 
A solution of 8 parts of 4-chloro-3,5-dinitrobenzotrifluoride in 20 parts 
of o-chlorobenzotrifluoride was vaporized and passed through a vapor phase 
reactor together with 12.6 parts of chlorine gas over a half hour period. 
Analysis of the reaction mixture indicated the major product to be 
3,4,5-trichlorobenzotrifluoride. The structure of the major product was 
confirmed by gas chromatography-mass spectrum analysis. 
EXAMPLE 17 
(A) In a continuous process about 30 parts per hour of 
3-chloro-4-fluoro-5-nitrobenzotrifluoride and about 26 parts per hour of 
chlorine gas were passed simultaneously through a vapor phase reactor 
maintained at a temperature of about 300.degree. to 350.degree. C. The 
vaporized reaction product was condensed and collected until about 14.4 
parts of the 3-chloro-4-fluoro-5-nitrobenzotrifluoride and about 13.7 
parts of chlorine gas had been passed through the reactor. Analysis of the 
reaction product indicated 12.4 parts of 
3,5-dichloro-4-fluorobenzotrifluoride, a yield of 90.2%. The structure of 
the product was confirmed by gas chromatography-mass spectrum analysis. 
(B) The 3-chloro-4-fluoro-5-nitrobenzotrifluoride starting reactant 
employed in the above example was prepared in the follow manner. A mixture 
of 52 parts of 3,4-dichloro-5-nitrobenzotrifluoride, 16.2 parts of 
anhydrous potassium fluoride and 2.5 parts of tetramethylammonium chloride 
was heated and maintained at about 120.degree. to 140.degree. C. for about 
7 hours. The mixture was then cooled to room temperature, diluted with 
methylene chloride, and filtered. The filtrate was distilled to yield 35.2 
parts (67% yield) of 3-chloro-4-fluoro-5-nitrobenzotrifluoride. The 
structure of the product was confirmed by gas chromatography-mass spectrum 
analysis. 
EXAMPLE 18 
In a continuous process, about 7.5 parts of 
4-fluoro-3-nitrobenzotrifluoride vapor and about 5.2 parts of hydrogen 
chloride gas were passed simultaneously through a vapor phase reactor 
maintained at a temperature of about 390.degree. to about 420.degree. C. 
over a forty minute period. The vaporized reaction product was condensed 
and collected. Analysis of the reaction mixture by gas chromatography 
indicated 3-chloro-4-fluorobenzotrifluoride as the major product.