Herbicidal cycloalkanapyrazoles of the formula: ##STR1## where N IS 3, 4 OR 5; PA1 R.sub.1 is hydrogen or methyl; PA1 Q is fluorine, chlorine, bromine or iodine; PA1 X is fluorine, chlorine, bromine, iodine, cyano, methoxy or nitro; PA1 Y is hydrogen, fluorine, or chlorine; PA1 Z is hydrogen or fluorine; and PA1 V is hydrogen, fluorine, chlorine or methoxy with the proviso that PA2 A. when n is 5, R.sub.1 must be hydrogen, Q must be chlorine or bromine, Z and V must both be hydrogen and Y must be hydrogen or fluorine; PA2 B. when n is 3 or 4 and Q is fluorine or iodine, R.sub.1, Z and V must be hydrogen and Y must be hydrogen or fluorine; PA2 C. when n is 3 and R.sub.1 is methyl, Q must be chlorine or bromine, Y must be hydrogen or fluorine and Z and V must both be hydrogen; and, PA2 D. when V is other than hydrogen, X must be fluorine, chlorine or bromine and Z must be hydrogen.

BACKGROUND OF THE INVENTION 
Recently, in German Offenlegungsschrift No. 2,165,651 a group of 
isoindole-1,3-diones which are useful as herbicides was disclosed. The 
general formula for the isoindole-1,3-diones disclosed in the 
Offenlegungsschrift is as follows: 
##STR2## 
wherein R may be an aryl, aralkyl or benzyl substituent optionally 
substituted with 1 to 5 halogen atoms or a hydroxy, nitro, cyano, 
thiocyanato, carboxy, alkyl or halogenated alkyl, alkoxy, lower alkylthio 
or phenyl group. R may also be optionally substituted with a group having 
the configuration --O--CH.sub.2 A where A is phenyl or a naphthyl group. 
The phenyl group may contain one or more halogen atoms, nitro groups, 
lower alkyl groups or lower alkoxy groups. 
Typical of the compounds disclosed in the Offenlegungsschrift is the 
compound of Structure 1: 
##STR3## 
Although the compounds disclosed within the Offenlegungsschrift are active 
herbicides, the need still exists for even better herbicides. Weeds are 
very damaging to important crops such as rice and wheat and they decrease 
crop yield. In the current world situation, wherein food shortages are 
acute, it is most important to harvest the maximum possible yields of 
crops such as rice or wheat. Thus, a need exists for a particularly 
effective herbicide which will destroy as many weeds as possible without 
causing significant damage to desired crops, e.g., rice or wheat. 
According to the instant invention, compounds have been discovered which 
are highly active herbicides and yet cause minimal damage to certain 
desired crops, e.g., rice and wheat, and especially the major world food 
crop, rice. 
The preparation and fungicidal utility of the 
2-(4-chlorophenyl)-1,2,4,5,6,7-hexahydroindazol-3(3H)-one is disclosed in 
Takeda Chem. Ind. Paper, Chem. Abs., 67, 11542h (1967). 
##STR4## 
2-Aryl-4,5,6,7-tetrahydro-1-alkyl-1H-indazol-3(2H)-ones are claimed as 
antipyretics in Ger. 668.628 [assigned to P. Bierdorf & Co. AG, Chem. 
Abs., 33, 5131.sup.2 (1939)] and U.S. Pat. No. 2,104,348 [assigned to E. 
R. Squibb, Co., Chem. Abs., 32, 1869.sup.1 (1938)]. 
##STR5## 
0041 
German Offenlegungsschrift No. 2,409,753 discloses herbicides having the 
general formula 
##STR6## 
in which 
R.sup.1 is hydrogen, an alkyl, cycloalkyl or aralkyl radical, a phenyl 
group which may be substituted or an acyl radical having the formula 
--CO--R.sup.6 or 
##STR7## 
R.sup.6 is hydrogen, an alkyl radical which may be substituted, an alkoxy 
or phenoxy radical or a phenyl radical and 
R.sup.7 and R.sup.8 are the same or different and can be hydrogen, alkyl, 
phenyl which may be substituted or alkinyl, 
R.sup.2 is an alkyl radical which may be substituted, a cycloalkyl radical 
or a phenyl radical which may be substituted or a heterocyclic radical 
with O, N or S atoms in the ring, 
R.sup.3 is hydrogen, chlorine, bromine or a low-molecular-weight alkyl 
radical, 
R.sup.4 is the radical --S--R.sup.5, --SO--R.sup.5 or --SO.sub.2 --R.sup.5 
and 
R.sup.5 is an alkyl radical, cycloalkyl radical, aralkyl radical or a 
phenyl group which may be substituted or a heterocyclic radical with O, N 
or S in the ring. 
An intermediate for preparing these herbicides by reaction with a mercaptan 
having the general formula R.sub.5 SH is 
##STR8## 
where R.sup.1, R.sup.2, R.sup.3 and R.sup.5 have the previously given 
meanings and Hal represents chlorine, bromine or iodine. 
1-Phenyl-3,4-trimethylenepyrazolone is disclosed in U.S. Pat. No. 1,685,407 
(1928) with utility as an intermediate for making dyes and medicinal 
compounds. C. Mannich in Arch. Pharm. 267, 699-702 (1929) and in Brit. 
260,577 describes the preparation of 1-phenyl-3,4-trimethylenepyrazolones. 
##STR9## 
R. P. Willliams et al. in J. Med. Chem. 13, 773 (1970) reports the 
preparation and evaluation as anti-inflammatory agents compounds of the 
following type: 
##STR10## 
X = H, Br, F. 
DESCRIPTION OF THE INVENTION 
This invention relates to the novel compounds of Formula I and to 
agricultural compositions containing them, and to the method of use of 
these compounds as selective, as well as general, herbicides having both 
pre- and post-emergence activity. 
##STR11## 
where n is 3, 4 or 5; 
R.sub.1 is hydrogen or methyl; 
Q is fluorine, chlorine, bromine or iodine; 
X is fluorine, chlorine, bromine, iodine, cyano, methoxy or nitro; 
Y is hydrogen, fluorine, or chlorine; 
Z is hydrogen or fluorine; and 
V is hydrogen, fluorine, chlorine or methoxy with the proviso that 
a. when n is 5, R.sub.1 must be hydrogen, Q must be chlorine or bromine, Z 
and V must both be hydrogen and Y must be hydrogen or fluorine; 
b. when n is 3 or 4 and Q is fluorine or iodine, R.sub.1, Z and V must be 
hydrogen and Y must be hydrogen or fluorine; 
c. when n is 3 and R.sub.1 is methyl, Q must be chlorine or bromine, Y must 
be hydrogen or fluorine and Z and V must both be hydrogen; and 
d. when V is other than hydrogen, X must be fluorine, chlorine or bromine 
and Z must be hydrogen. 
Of those compounds of Formula I, preferred for their high herbicidal 
activity or favorable cost or both, are those compounds where, 
independently, 
1. n is 3 or 4; 
2. Q is chlorine or bromine; 
3. R.sub.1 is hydrogen or methyl; 
4. Z and V are both hydrogen; 
5. Y is hydrogen or fluorine; or, 
6. X is fluorine, chlorine, bromine, cyano or methoxy. 
Of those compounds of Formula I where n is 4, preferred are those where Q 
is chlorine or bromine. 
More preferred are those compounds where n is 4, Q is chlorine or bromine, 
and R.sub.1 is hydrogen. 
Of those compounds of Formula I where n is 4, Q is chlorine or bromine and 
R.sub.1 is hydrogen, preferred are those compounds where, independently, 
1. Z and V are both hydrogen; 
2. Y is hydrogen or fluorine; or 
3. X is fluorine, chlorine, bromine, cyano or methoxy. 
More preferred still are those compounds where n is 4, Q is chlorine or 
bromine, R.sub.1 is hydrogen and Z and V are both hydrogen. 
Of those compounds of Formula I where n is 4, Q is chlorine or bromine, 
R.sub.1 is hydrogen and Z and V are both hydrogen, preferred for their 
higher herbicidal activity or more favorable cost or both, are those 
compounds where, independently, 
1. Y is hydrogen or fluorine; or, 
2. X is fluorine, chlorine, bromine, cyano or methoxy. 
More preferred are those compounds where n is 4, Q is chlorine or bromine, 
R.sub.1 is hydrogen, Z and V are both hydrogen, Y is hydrogen or fluorine 
and X is fluorine, chlorine, bromine, cyano or methoxy. 
Most preferred for their excellent herbicidal activity or highly favorable 
cost or both are those compounds of Formula I where n is 4, Q is chlorine 
or bromine, R.sub.1 is hydrogen, Z and V are both hydrogen, Y is hydrogen 
or fluorine, and X is chlorine or bromine. 
Of those compounds of Formula I where n is 3, preferred are those compounds 
where Q is chlorine or bromine. 
More preferred are those compounds where n is 3, Q is chlorine or bromine, 
and R.sub.1 is hydrogen. 
Of those compounds of Formula I where n is 3, Q is chlorine or bromine and 
R.sub.1 is hydrogen, preferred are those compounds where, independently, 
1. Z and V are both hydrogen; 
2 Y is hydrogen or fluorine; or, 
3. X is fluorine, chlorine, bromine, cyano or methoxy. 
Most preferred are those compounds where n is 3, Q is chlorine or bromine, 
R.sub.1 is hydrogen and Z and V are both hydrogen. 
Of those compounds of Formula I where n is 3, Q is chlorine or bromine, 
R.sub.1 is hydrogen and Z and V are both hydrogen, preferred for their 
higher herbicidal activity or more favorable cost or both, are those 
compounds where, independently, 
1. Y is hydrogen or fluorine; or, 
1. X is fluorine, chlorine, bromine, cyano or methoxy. 
More preferred are those compounds where n is 3, Q is chlorine or bromine, 
R.sub.1 is hydrogen, Z and V are both hydrogen, Y is hydrogen or fluorine 
and X is fluorine, chlorine, bromine, cyano or methoxy. 
Most preferred for their excellent herbicidal activity or highly favorable 
cost or both are those compounds of Formula I where n is 3, Q is chlorine 
or bromine, R.sub.1 is hydrogen, Z and V are both hydrogen, Y is hydrogen 
or fluorine, and X is chlorine or bromine. 
Of those compounds of Formula I, preferred for their high herbicidal 
activity or favorable cost or both, are those compounds where Y is 
hydrogen or fluorine and Z and V are both hydrogen. 
More preferred are those compounds where Y is hydrogen or fluorine and Z 
and V are both hydrogen where, independently, 
1. Q is chlorine; or, 
2. X is chlorine or bromine. 
Of those compounds of Formula I, preferred for their higher herbicidal 
activity or more favorable cost or both, are those compounds where Y is 
hydrogen or fluorine, Z and V are both hydrogen and Q is chlorine. 
Most preferred for their excellent herbicidal activity or highly favorable 
cost or both are those compounds of Formula I where Y is hydrogen or 
fluorine, Z and V are both hydrogen, Q is chlorine, and X is chlorine or 
bromine. 
Specifically preferred for thier outstanding herbicidal activity or 
favorable cost or both are 
1. 3-Chloro-2-(4-chloro-2-fluorophenyl)-4,5,6,7-tetrahydro-2H-indazole; 
m.p. 88.degree.-89.5.degree. C; 
2. 3-chloro-2-(4-chlorophenyl)-4,5,6,7-tetrahydro-2H-indazole; m.p. 
81.degree.-84.degree.; 
3. 3-Bromo-2-(4-chloro-2-fluorophenyl)-4,5,6,7-tetrahydro-2H-indazole; m.p. 
95.degree.-98.degree. C; 
4. 3-chloro-2-(4-bromo-2-fluorophenyl)-4,5,6,7-tetrahydro-2H-indazole; m.p. 
86.degree.-88.degree. C; 
5. 
3-chloro-2-(4-chloro-2-fluorophenyl)-2,4,5,6-tetrahydrocyclopentapyrazole; 
m.p. 101.5.degree.-104.degree. C; and , 
6. 3-Chloro-2-(4-chlorophenyl)-2,4,5,6-tetrahydrocyclopentopyrazole; m.p. 
114.5.degree.-117.degree. C. 
SYNTHESIS OF THE COMPOUNDS 
The novel cycloalkanapyrazoles of Formula I where Q is Cl or Br are 
prepared in two steps as shown by Equations A and B: 
##STR12## 
where R.sub.1, n, X, Y, V and Z are as defined above; 
Q is Br or Cl; 
R is alkyl of 1 to 3 carbon atoms; 
f is 0 or 1; and 
A is an anion of the corresponding acid HA having an ionization constant of 
at least 1 .times. 10.sup.-7, e.g. H.sub.2 SO.sub.4 or HCl. 
The preparation of the annelated pyrazolones 3 is known in the literature; 
for example, the preparation of 
2-aryl-1,2,4,5,6,7-hexahydro-3H-indazol-3-ones (3, n = 4) is described in 
W. Dieckmann, Ann., 317, 102 (1901). The .beta.-keto ester 2 is combined 
with the appropriate aryl hydrazine acid salt 1 in an appropriate solvent, 
such as a lower alcohol, or aromatic hydrocarbon, and, optionally, in the 
presence of an acid acceptor, such as a tertiary organic amine or alkali 
metal hydroxide or alkoxide and the reaction mixture is heated at reflux 
for 0.5-24 hours. The pyrazolone 3 is isolated by conventional techniques 
such as by pouring the reaction mass into water and filtering the product. 
The crude product is usually of sufficient purity to be used directly in 
the next step. If necessary, further purification can be accomplished by 
recrystallization, sublimation, or other conventional techniques known to 
those skilled in the art. This same procedure can be used to prepare those 
compounds of formula 3 in which n = 5. 
The pyrazolones 3 where n is 3 are prepared by combining the appropriate 
aryl hydrazine with the appropriate alkyl 2-oxocyclopentanecarboxylate in 
a suitable solvent such as toluene or chlorobenzene. The reaction is 
heated at reflux and water is simultaneously removed to yield a hydrazone. 
Cyclization to the pyrazolones 3 where n is 3 is then effected by adding 1 
-3 equivalents of an alkali metal alkoxide such as sodium methoxide to the 
hydrazone solution and heating for 1-5 hours at 80.degree.-130.degree. C. 
Methods taught in Arch. Pharm., 267, 699-702 (1929) and in J. Med. Chem., 
13, 733 (1970) are also useful in preparing pyrazolones of fromula 3 in 
which n = 3. 
##STR13## 
Alternatively, the hydrazone may be isolated and subsequently cyclized by 
treatment with the two equivalents of n-butyl lithium in a solvent such as 
THF at temperatures of 0.degree.-60.degree. C for a period of 2-18 hours. 
The pyrazolones 3 where n is 3 are isolated by pouring the reaction mass 
into water, separating the organic layer and acidifying the aqueous layer 
with a mineral acid, i.e., HCl, H.sub.2 SO.sub.4. From the acidified 
aqueous layer the desired product is obtained by filtration, 
centrifugation, extraction or other similar techniques. 
The novel cycloalkanapyrazoles of Formula I hich Q is chlorine are obtained 
by heating the annelated pyrazolones 3 with phosphorous oxychloride 
(formula 4, Q is chlorine). When Q is bromine in Formula 1, phosphorous 
oxybromide (formula 4, Q is bromine) in the presence of an 
N,N-dialkylaniline and dimethylformamide is used (Equation B). 
The use of an inert organic solvent such as methylene chloride or toluene 
is optional; however, it is preferred that no solvent other than the 
phosphorous oxychloride or bromide be used. The mixture is heated at 
100.degree.-180.degree. C, preferably 140.degree.-150.degree. C., for a 
period of 1-10 hours. The crude reaction mixture is dissolved in an inert 
organic solvent (e.g., CHCl.sub.3, CH.sub.2 Cl.sub.2, or toluene), and the 
solution is washed with dilute aqueous base (e.g., NaOH or KOH) followed 
with water. The organic phase is dried, and the solvent is removed on a 
rotary evaporator or by distillation. The product obtained is the pyrazole 
of Formula I and may be purified by distillation, sublimation or 
crystallization from an appropriate solvent. 
Compounds of Formula I where Q is iodine are prepared from corresponding 
aminopyrazoles via diazotization with nitrous acid and reaction with 
potassium iodide according to the method of Spanish Pat. No. 394,208 [Chem 
Abst., 83, 972834 (1975)]. The required aminopyrazoles are prepared from 
the appropriate .alpha.-cyanocyclohexanone or .alpha.-cyanocyclopentanone 
by reaction with appropriate aryl hydrazine in a solvent such as toluene. 
The overall sequence for preparing compounds of Formula I where Q is 
iodine is illustrated by equation A.sub.2 and B.sub.2 : 
##STR14## 
The required .alpha.-cyanoketones can be prepared by a number of methods as 
well known in the art. For examples, .alpha.-cyanocyclohexanone is 
prepared from .alpha.-chlorohexanone and sodium cyanide according to R. 
Meyer in Helv. Chim. Acta, 16, 1291 (1933). .alpha.-Cyanocyclopentanone is 
prepared from adiponitrile and a strong base such as a lithium 
dialkylamide followed by acid hydrolysis according to Ger. 591,269 (Jan., 
1934) [C.A. 28, 117 (1934)]. .alpha.-Cyanocycloaliphatic ketones can also 
be prepared from cycloalkanone enamines and cyanogen chloride according to 
the method of M. E. Kuehne, J. Am. Chem. Soc., 81, 5400 (1959). 
Compounds of Formula I where Q is fluorine are prepared as shown in 
equations A.sub.3 and B.sub.3 from photolysis of corresponding 3-diazonium 
fluoborate (equation B.sub.3) which in turn are obtained by diazotization 
of 3-aminopyrazoles with nitrous acid in fluoboric acid (equation A.sub.3) 
according to the method of E. D. Bergmann, J. Am. Chem. Soc., 78, 6037 
(1956). 
##STR15## 
Intermediate .beta.-keto esters 2 are commercially available or are 
prepared by methods well described in the literature: G. Stork et al., J. 
Am. Chem. Soc., 85, 207 (1963). The general procedure is shown in 
Equations C, D and E: 
##STR16## 
Enamine 7 is prepared by heating ketone 5 and morpholine 6 (pyrrolidine may 
also be used) in an appropriate solvent, such as benzene, toluene, or 
chlorobenzene, with simultaneous removal of water from the reaction by 
azeotropic distillation (Equation C). The alkyl chloroformate 8 is added 
to the enamine 7, and this mixture is heated at a temperature from 
70.degree. C to the boiling point of the solvent for a period of 1-10 
hours. The enamine hydrochloride 10 which is produced as a by-product in 
the reaction is removed by filtration. The morpholine enamine 9, which is 
contained in the organic filtrate, is converted to the .beta.-keto ester 2 
hydrolysis with aqueous mineral acid (e.g., hydrochloric acid) at 
temperatures ranging from ambient to 75.degree. C (Equation E). The 
product is isolated by conventional techniques such as extraction into a 
suitable organic solvent followed by evaporation of the solvent. The 
product may be further purified by fractional distillation under reduced 
pressure, sublimation, or crystallization. 
The use of 3-methylcyclohexanone 5a leads to a mixture of 
methyl-substituted .beta.-keto esters (2a and 2b). If this mixture of 
methyl-substituted .beta.-keto esters is reacted with an aryl hydrazine, a 
mixture of 4- and 
6-methyl-substituted-2-aryl-1,2,4,5,6,7-hexahydro-3H-indazol-3-ones (3a 
and 3b) is produced; subsequent treatment with phosphorous oxyhalide 4 
will produce a mixture containing both the 4- and 
6-methyl-substituted-3-halo-2-aryl-tetrahydroindazoles of this invention. 
If the mixture of isomeric methyl cyclohexanones is separated, then 2a and 
2b will lead to 3a an 3b respectively when treated with an arylhydrazine. 
##STR17## 
In the case of the 2- or 4-methylcyclohexanones, the .beta.-keto ester 
synthesis is more specific and predominately one isomer is produced, as 
summarized schematically in Equations F and G. 2-Methylcyclohexanone 
produces 7-methyl-3-halo-2-aryl-4,5,6,7-tetrahydroindazole, and 
4-methylcyclohexanone produces 
5-methyl-3-halo-4,5,6,7-tetrahydroindazoles. 
##STR18## 
The required alkyl-2-oxocyclopentanecarboxylates can be prepared by methods 
previously described and by methods described in Organic Reactions, 15, 
1-203 (1967). 
The preparation of aryl hydrazines 1 from anilines is well documentated in 
the literature: G. H. Coleman, Organic Syntheses, Coll. Vol. I, J. Wiley & 
Sons, New York, p. 442 and H. Kindler et al., Fr. 1,419,092. A general 
procedure is illustrated in Equation H: 
##STR19## 
The aniline 11 is diazotized at about -5 to 5.degree. C with sodium nitrite 
in aqueous acid (HA, where A is defined as above) such as hydrochloric 
acid; the resulting solution is mixed with an aqueous sodium bisulfite 
solution at 0.degree.-20.degree. C, heated to 50.degree.-80.degree. C for 
0.5-2 hr. and then acidified with the mineral acid to give the aryl 
hydrazine acid salt 1. The hydrazine salt often crystallizes directly from 
the reaction mixture and can be isolated by filtration or by other 
conventional techniques. In most instances the hydrazine can be used 
without further purification. 
Certain hydrazines used in preparing compounds defined by this invention 
are novel; e.g., 4-chloro-2-fluorophenylhydrazine hydrochloride is a novel 
compound which can be prepared by the method described above. The 
following novel hydrazines can also be prepared by this method: 
4-bromo-2-fluorophenylhydrazine hydrochloride 
2-fluoro-4-methoxyphenylhydrazine hydrochloride 
2,4,6-trifluorophenylhydrazine hydrochloride 
2-fluoro-4-nitrophenylhydrazine hydrochloride 
4-cyano-2-fluorophenylhydrazine hydrochloride 
Also useful for preparing aryl hydrazines is the method described by M. S. 
Gibson et al., J. Chem. Soc. (C) 1970, 2106 and M. S. Gibson et al., J. 
Chem. Soc. (C), 1974, 215. 
Representative aniline starting materials for these hydrazines are prepared 
as described below. 4-Chloro-2-fluoroaniline, for example, can be prepared 
from 2'-fluoroacetanilide [G. Schiemann and H. G. Baumaarten, Chem. 
Berichte, 70, 1416 (1937)] by the reaction sequences shown below: 
##STR20## 
STEP A 
Chlorination of acetanilides in acetic acid is well known to those skilled 
in the art and may be carried out under the condition taught in W. W. Reed 
and K. J. P. Orton, J. Chem. Soc., 91, 1543 (1907) for the chlorination of 
acetanilide. The chlorination of 2'-fluoroacetanilide takes place at 
25.degree.-30.degree. C over several hours (e.g. 5) at atmospheric 
pressure. The resulting product is 4'-chloro-2'-fluoroacetanilide. 
STEP B 
The chlorofluoroacetanilide is refluxed in a mixture of a lower alcohol 
(50%) (e.g. ethanol) and concentrated hydrochloric acid (50%) for several 
hours (e.g. 5 or more) at 70.degree.-90.degree. C and atmospheric 
pressure. The solvent mixture is removed at a reduced pressure of 100 to 
300 mm. Hg and at a temperature of 20.degree.-50.degree. C. to leave a 
residue of the hydrochloride salt of 4-chloro-2-fluoroaniline. 
STEP C 
After basification of an aqueous solution of the hydrochloride salt of 
4-chloro-2-fluoroaniline with an alkali metal hydroxide solution, such as 
50% sodium hydroxide at ambient conditions, the free 
4-chloro-2-fluoroaniline is extracted into a suitable water-immiscible 
organic solvent such as ethyl ether or methylene chloride. Crude 
4-chloro-2-fluoroaniline is isolated by removal of the organic solvent 
under a reduced pressure of 100 to 300 mm. Hg at 20.degree.-50.degree. C. 
2-Fluoro-4-bromoaniline can be prepared by bromination of 2-fluoroaniline 
[prepared in Chem. Berichte, 70, 1416 (1937)] with N-bromosuccinimide as 
shown in the following equation. 
##STR21## 
Bromination of anilines using N-bromosuccinimide in an inert organic 
solvent such as methylene chloride is well known to those skilled in the 
art, e.g., J. B. Wommack et al., J. Het. Chem., 6, 243 (1969). Bromination 
of 2-fluoroaniline is a exothermic reaction that takes place at 0.degree. 
C over several hours, e.g. 5 or more. The resulting reaction mixture is 
washed with water several times and dried with an appropriate drying agent 
such as anhydrous sodium sulfate. The 4-bromo-2-fluoroaniline is recovered 
by removal of the organic solvent under a reduced pressure of 100 to 300 
mm. Hg at 20.degree.-50.degree. C. 
2,4,6-Trifluoroaniline is prepared by reduction of 
1,3,5-trifluoro-2-nitrobenzene [V. I. Siele and H. J. Matsugama, U.S. 
Department Commerce, Office Serv., P B Rept. 145, 510, p. 1 (1960) or 
Chem. Abst., 56, 15394c (1962)] using the procedures described by G. 
Schiemann and M. Seyhan, Chem. Berichte, 70, 2396 (1937). 
##STR22## 
2,4-Difluoroaniline is known to the art and can be prepared by the 
procedure described in G. Scheimann and M. Seyhan Chem. Berichte, 70, 2396 
(1937). 
4-Amino-3-fluorobenzonitrile, used in the preparation of 
4-cyano-2-fluorophenylhydrazine hydrochloride, can be prepared from 
4-bromo-2-fluoroaniline by treatment with cuprous cyanide in 
N-methylpyrrolidone using known procedures: L. Friedman, et al., J. J. 
Chem., 26, 2522 (1961). The reaction mixture is heated to reflux for 
several hours and then poured onto ice and sodium cyanide. The resulting 
solution is heated between 50.degree.-80.degree. C for a period of 1-3 
hours, cooled, and extracted with toluene; the toluene extract is washed 
with water, dried with suitable drying agent, and evaporated to give 
4-amino-3-fluorobenzonitrile. 
2-Fluoro-4-methoxyaniline, used in the preparation of 
2-fluoro-4-methoxyphenylhydrazine hydrochloride, is known and can be 
prepared by the method of H. Hodgson, et al., J. Chem. Soc., 1268 (1940). 
2-Fluoro-4-nitroaniline, used to prepare 2-fluoro-4-nitrophenylhydrazine 
hydrochloride, is also a known compound and can be prepared according to 
the method of J. B. Dickey, U.S. Pat. No. 2,436,100. 
The following examples further illustrate the method for synthesis of 
compounds of this invention. All parts are by weight and all temperatures 
in degrees centigrade.