Compositions containing active substances of the formula ##STR1## wherein R.sub.1 and R.sub.2, each independently of the other, represent hydrogen or alkyl of 1 to 10 carbon atoms, R.sub.3 and R.sub.4, each independently of the other, represent alkyl of 1 to 5 carbon atoms or halogen, preferably chlorine, and R.sub.5 represents hydrogen, alkyl of 1 to 5 carbon atoms or halogen, or an acid addition salt thereof for combating ectoparasites.

The present invention relates to compositions for controlling ectoparasites 
and to a method of controlling ectoparasites, in particular mites and 
ticks, which comprises the use of said compositions. 
The compositions of the present invention contain, as active component, at 
least one compound of the formula I 
##STR2## 
wherein R.sub.1 and R.sub.2, each independently of the other, represent 
hydrogen or alkyl of 1 to 10 carbon atoms, 
R.sub.3 and R.sub.4, each independently of the other, represent alkyl of 1 
to 5 carbon atoms or halogen, preferably chlorine, and 
R.sub.5 represents hydrogen, alkyl of 1 to 5 carbon atoms or halogen, 
or an acid addition salt thereof. 
By alkyl groups within the scope of formula I are meant both straight chain 
and branched alkyl groups, for example methyl, ethyl, and the isomers of 
the propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl and decyl groups. 
Halogen is to be understood as meaning fluorine, bromine, iodine and, 
preferably, chlorine. 
The compounds of the formula I can be converted into their acid addition 
salts by methods which are known per se. Preferred acid addition salts are 
the hydrochlorides. In addition to hydrochloric acid suitable acids for 
the salt formation are for example: hydrobromic acid, hydriodic acid, 
sulfuric acid, phosphoric acid, nitric acid, acetic acid, propionic acid, 
butyric acid, valeric acid, oxalic acid, malonic acid, succinic acid, 
malic acid, maleic acid, fumaric acid, lactic acid, tartaric acid, citric 
acid, benzoic acid, phthalic acid, cinnamic acid and salicyclic acid. 
Some of the compounds falling within the scope of the formula I are known. 
These compounds are disclosed as pharmaceutically active in British Pat. 
No. 1,174,349. Furthermore, Japanese published Pat. No. 51-106739 
discloses compounds of the following general formula as active ingredients 
of insecticidal and acaricidal formulations: 
##STR3## 
wherein A represents lower alkylene or lower alkenylene, B represents an 
oxygen or a sulfur atom, the NH or NCH.sub.3 group, R.sub.1 ' represents 
phenyl, thienyl or naphthyl, each of which is unsubstituted or substituted 
by 1 to 3 halogen atoms, nitro, lower alkyl or haloalkyl and R.sub.2 ' 
represents hydrogen or lower alkyl and m is 0 or 1. 
The present invention is based on the observation that the compounds of the 
formula I possess valuable ectoparasiticidal, especially acaricidal, 
properties. It has been found that the compounds of the formula I are 
significantly superior in respect of their acaricidal action to the 
individual compounds specifically described in the Japanese patent 
specification referred to above. 
The compounds of the formula I can be obtained by methods which are known 
per se, for example in accordance with the syntheses illustrated by the 
following formulae: 
##STR4## 
The processes are carried out in the temperature range between 40.degree. 
and 180.degree. C. and in the presence of anhydrous solvents or also 
without solvents. Examples of suitable solvents are: methanol, ethanol, 
propanol, butanol, xylene and dichlorobenzene. 
The above syntheses are described in the following publications: 
U.S. Pat. No. 2,252,753; Helv. Chimica Acta 33, 1386 (1950); U.S. Pat. No. 
2,252,721; and British Pat. No. 1,174,349. 
The individual starting materials and their manufacture are known from the 
following publications: 
##STR5##

The following Examples serve to illustrate the manufacture of the compounds 
of the formula I: 
EXAMPLE 1 
(Method a) 
2-(2',3'-Dimethylphenylaminomethyl)-2-imidazoline hydrochloride 
31 g of 2-chloromethyl-2-imidazoline hydrochloride and 48.4 g of 
2,3-dimethylaniline are refluxed for 5 hours in 65 ml of absolute ethanol. 
After cooling, the crystallised substance is collected by suction and 
recrystallised from water, affording 36 g (77% yield) of the final product 
with a melting point of 242.degree. C. 
EXAMPLE 2 
(Method d) 
2-(2',3'-Dimethylphenylaminomethyl)-2-imidazoline 
A mixture of 26.4 g of 2,3-dimethylphenylacetonitrile and 39.4 g of 
ethylenediamine toluenesulfonate is heated to 140.degree. C. until the 
evolution of ammonia ceases. Then 150 ml of 15% aqueous sodium hydroxide 
are added to the oily reaction product, which is extracted with three 100 
ml portions of methylene chloride. The combined methylene chloride 
extracts are washed with water, dried over sodium sulfate and filtered. 
The solvent is distilled off and the residual dark oil is distilled in 
vacuo, affording 13.6 g (39.4% of theory) of 
2-(2',2'-dimethylphenylaminomethyl)-2-imidazoline in the form of an oil 
with a boiling point of 154.degree.-160.degree. C./0.2 torr. On standing, 
this oil solidifies to crystals with a melting point of 
80.degree.-82.degree. C. 
The following new compounds have been prepared by procedures analogous to 
those described in the foregoing Examples and to the other indicated 
methods: 
______________________________________ 
##STR6## 
melting point 
No. R.sub.1 R.sub.2 
R.sub.3 
R.sub.4 
R.sub.5 
salt in .degree. C. 
______________________________________ 
1 H H CH.sub.3 
CH.sub.3 
H HCl 242 
2 H H Cl Cl H HCl 260 
3 H H CH.sub.3 
CH.sub.3 
6-CH.sub.3 
HCl 215 
4 CH.sub.3 
H CH.sub.3 
CH.sub.3 
H HCl 190-192 
5 CH.sub.3 
CH.sub.3 
CH.sub.3 
CH.sub.3 
H HCl 183-184 
6 CH.sub.3 
H Cl Cl H HCl 226-227 
7 CH.sub.3 
CH.sub.3 
Cl Cl H HCl 
8 CH.sub.3 
H CH.sub.3 
Cl H HCl 212-214 
9 CH.sub.3 
CH.sub.3 
CH.sub.3 
Cl H HCl 
10 H CH.sub.3 
CH.sub.3 
CH.sub.3 
H HCl 182-183 
11 H H CH.sub.3 
CH.sub.3 
H -- 80-82 
______________________________________ 
The novel compounds of the formula I also constitute an object of the 
present invention. 
The compounds of the formula I as such or as constituents of the 
compositions of the invention possess valuable ectoparasiticidal 
properties. They are suitable in particular for controlling mites 
(Acarina), preferably parastic ticks (Ixodidae). This applies to all 
stages of monoxenous and heteroxenous tick species and to the inhibition 
of oviposition, that is to say both to strains which are normally 
sensitive and those which are resistant to compounds such as phosphates, 
carbamates and other already known acaricides. 
In addition, these compounds have a pronounced detaching effect, which is 
of particular importance for the treatment of host animals which are 
already infested with ticks (e.g. cattle or rabbits). The detaching effect 
commences directly after application of the active substance, as a 
consequence of which the ticks are prevented from continuing to feed on 
the host by sucking blood from it. In the course of the treatment they 
become detached from the host animal, which is ultimately completely freed 
from the pests. 
Preferred compounds of the present invention are those of the formula I 
wherein the substituent at the phenyl ring, R.sub.5, represents hydrogen, 
whilst R.sub.3 and R.sub.4, each independently of the other, are as 
defined for formula I. 
The following compounds are distinguished by excellent acaricidal action: 
2-(2',3'-dimethylanilinomethyl)-2-imidazoline hydrochloride 
2-(2',3'-dichloroanilinomethyl)-2-imidazoline hydrochloride. 
EXAMPLE 3 
Test of the action against ticks: inhibition of oviposition 
The test organisms are fully gorged females of the cattle tick, Boophilus 
microplus. 10 ticks of a resistant strain and 10 ticks of a normally 
sensitive strain are treated at each concentration. The ticks are dipped 
briefly into aqueous emulsions or aqueous solutions of the salts of the 
compounds to be examined. They are affixed to plates covered with double 
adhesive tape and stored in a climatically controlled room under constant 
conditions. Evaluation is made after three weeks. Total inhibiton of the 
deposition of fertile eggs is ascertained. 
The inhibitory action of the substances is expressed as the minimum 
substance concentration in ppm for 100% action against normally sensitive 
and resistant adult female ticks. 
______________________________________ 
Results 
Minimum concentration in 
ppm at 100% inhibitory 
action 
Compound .female. sensitive 
.female. resistant 
______________________________________ 
(1) 2-(2',3'-dimethylanilino- 
50 50 
methyl)-2-imidazoline- 
hydrochloride 
(2) 2-(2' ,3' -dichloroanilino- 
50 50 
methyl)-2-imidazoline- 
hydrochloride 
Comparison 
2-(3,4-dichlorophenylimino)- 
1000 1000 
N-n-butyl-pyrrolidine ("Bima 
rit") 
rit" &gt;1000 &gt;1000 
methyl-thiazoline (Swiss 
Patent 439,858) 
2-3,4-dichlorophenylimino)-3- 
&gt;1000 &gt;1000 
methyl-thiazoline-HCl 
(Swiss Patent 439,858) 
2-(4-chlorophenylimino)-3- 
&gt;1000 &gt;1000 
methylthiazoline-HCl 
(Swiss Patent 439,858) 
1-naphthyl-N-methylcarbamate 
1000 &gt;1000 
("Sevin"; U.S. Pat. No. 
2,903,478) 
empir. C.sub.10 H.sub.10 Cl.sub.8 ("Toxaphen"; 
1000 1000 
U.S. Pat. No. 2,565,471) 
______________________________________ 
EXAMPLE 4 
Test of the action against ticks: knock-down action against various 
development stages. 
The test organisms are about 50 larvae, about 25 nymphs or about 10 
imagines of each of the tick species Amblyomma hebraeum and Rhipicephalus 
bursa. The test organisms are dipped for a short time into aqueous 
emulsions or solutions having a specific concentration of the salts of the 
substances to be examined. The emulsions or solutions, which are contained 
in small test tubes, are then absorbed by cottonwool and the wetted test 
animals are left in the contaminated small tubes. The larvae are evaluated 
after 3 days and the nymphs and imagines after 14 days. The minimum 
substance concentration which effects 100% kill (LC.sub.100) is 
determined, expressed in ppm of active substance based on the total of 
emulsion or solution. 
______________________________________ 
Results 
LC.sub.100 
A. hebraeum 
R. bursa 
ima- 
Compound nymphs larvae gines larvae 
______________________________________ 
(1) 2-(2',3'-dimethyl- 
anilinomethyl)-2- 
imidazoline-hydrochloride 
1 1 50 1 
(2) 2-(2',3'-dichloroanilino- 
methyl)-2-imidazoline- 
hydrochloride 1 1 100 1 
Comparison 
2-(3,4-dichlorophenyl- 
imino)-N-n-butylpyrro- 
lidine ("Bimarit") 
100 100 100 10 
1-naphthyl-N-methyl-carba- 
mate ("Sevin":U.S. 
Pat. No. 2,903,478) 
10 5 100 10 
______________________________________ 
The compounds of the formula I are used as compositions of the invention 
together with suitable carriers and/or adjuvants. Suitable carriers and 
adjuvants can be solid or liquid and are the substances conventionally 
used in the art of formulation, for example natural or regenerated 
substances, solvents, despersing agents, wetting agents, adhesives, 
thickeners and binders. 
For application, the compounds of the formula I can be processed to dusts, 
emulsifiable concentrates, granules, dispersions, sprays, or to solutions 
or suspensions, in the conventional formulation which is commonly employed 
in application technology. 
The compositions of the present invention are prepared in a manner known 
per se by homogeneously mixing and/or grinding the active ingredients of 
the formula I with suitable carriers, with or without the addition of 
despersing agents and solvents which are inert to the active ingredients. 
The active ingredients may be processed to the following formulations: 
Solid formulations: dusts, tracking powders and granules (coated granules, 
impregnated granules and homogeneous granules); 
Liquid formulations: 
(a) active ingredient concentrates which are dispersible in water: wettable 
powders, pastes and emulsions; 
(b) solutions: pour-on. 
The content of active ingredient in the above described formulations is 
preferably between 1 and 80%. 
EXAMPLE 5 
Emulsifiable concentrate 
20 parts by weight of a compound of the formula I are dissolved in 70 parts 
by weight of xylene and to this solution are added 10 parts by weight of 
an emulsifier consisting of a mixture of arylphenyl polyglycol ether and 
the calcium salt of dodecylbenzenesulfonic acid. The emulsifiable 
concentrate can be diluted with water in any ratio to form a milky 
emulsion. 
EXAMPLE 6 
Emulsifiable concentrate 
With stirring, 5 to not more than 30 parts by weight of a compound of the 
formula I are dissolved at room temperature in 30 parts by weight of 
dibutyl phthalate, 10 parts by weight of Solvent 200 (high-aromatic 
mineral oil distillate of low viscosity) and 15 to 35 parts by weight of 
Dutrex 238 FC (viscous high-aromatic mineral oil distillate). Then 10 
parts by weight of an emulsifier mixture consisting of castor oil 
polyglycol ether and the calcium salt of dodecylbenzenesulfonic acid are 
added. The resulting emulsifiable concentrate gives milky emulsions in 
water. 
EXAMPLE 7 
Wettable powder 
5 to 30 parts by weight of a compound of the formula I are mixed 
intensively, in a mixing apparatus, with 5 parts by weight of an absorbent 
carrier (silica K 320 or Wessalon S) and 55 to 80 parts by weight of a 
carrier (bolus alba or kaolin B 24) and a mixture of dispersing agents 
consisting of 5 parts by weight of a Na laurylsulfonate and 5 parts by 
weight of an alkylaryl polyglycol ether. This mixture is ground to 5-15 
.mu.m in a pin mill or air jet mill. The resulting wettable powder gives a 
good suspension in water. 
EXAMPLE 8 
Dust 
5 parts by weight of a compound of the formula I (powder) are mixed 
intensively with 2 parts by weight of precipitated silica and 93 parts by 
weight of talc. 
EXAMPLE 9 
Pour-on solution 
______________________________________ 
Compound of the formula I 
30.0 g 
sodium dioctylsulfosuccinate 
3.0 g 
benzyl alcohol 48.0 g 
groundnut oil 19.8 g 
100.8 g = 100 ml 
______________________________________ 
The active substance is dissolved in benzyl alcohol with stirring and if 
necessary also with gentle warming. The sodium dioctylsulfosuccinate and 
the groundnut oil are added to the solution and dissolved, with warming 
and thorough mixing. 
EXAMPLE 10 
Pour-on solution 
______________________________________ 
Compound of the formula I 
30.00 g 
sodium dioctylsulfosuccinate 
3.00 g 
benzyl alcohol 35.46 g 
ethylene glycol monomethyl ether 
35.46 g 
103.92 g = 100 ml 
______________________________________ 
The active substance is dissolved in the bulk of the mixture of the two 
solvents with vigorous stirring. The sodium dioctylsulfosuccinate is then 
dissolved, with warming if necessary, and finally the solution is bulked 
with the remainder of the solvent mixture.