GB1587572A - 2-cyclopropylamino-4-formamidino-6-aminos-triazines and their use as insecticides - Google Patents

Description

(54) 2-CYCLOPROPYLAMINO-4-FORMAMIDINO-6-AMINO-S-TRIAZINES AND THEIR USE AS INSECTICIDES (71) We, CIBA-GEIGY AG., a Swiss Body Corporate, of Basle, Switzerland, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to 2-cyclopropylamino-4-formamidino-6-amino-s-triazine derivatives, to a process for their manufacture and to their use as insecticides.

The 2-cyclopropylamino-4-formamidino-6-amino-s-triazine derivatives of the invention have the formula

wherein R1 represents hydrogen, C,-C4-alkyl which is unsubstituted or substituted by C1-C4-alkoxy, or represents C3-C4- alkenyl, C3-C4-alkynyl, cyclopropyl, hydroxyl, methoxy or ethoxy, R2 represents hydrogen, methyl or ethyl, or R1 and R2 together with the nitrogen atom to which they are attached represent a 5- or 6-membered heterocyclic ring in which the nitrogen atom shown is the sole hetero-atom or which contains a further nitrogen atom or an oxygen atom, R3 represents methyl or ethyl, R4 represents methyl or ethyl, and R5 represents hydrogen or methyl.

Possible alkyl groups represented by R1 can be straight-chain or branched, unsubstituted or substituted by lower alkoxy groups of 1 to 4 carbon atoms. Examples of such alkyl groups include: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec. and tert. butyl and 2-methoxyethyl. Examples of possible C3 or C4-alkenyl and C3 or C4-alkynyl groups represented by R, include allyl and propargyl respectively.

Preferred compounds on account of their action are compounds of the formula I in which Rl represents hydrogen, C,-C4-alkyl which is unsubstituted or substituted by C1-C4-alkoxy, or represents C3 or C4-alkenyl, C3 or C4-alkynyl, cyclopropyl, hydroxyl, methoxy or ethoxy; R2 represents hydrogen, methyl or ethyl, or R1 and R2 together with the nitrogen atom to which they are attached represent 1-pyrrolidinyl, 1-piperidinyl, 4-morpho-linyl, 1-piperazinyl, 1-(4-methyl)-piperazinyl or 1-imidazolyl, R3 represents methyl or ethyl, R4 represents methyl or ethyl and R5 represents hydrogen or methyl.

Particularly advantageous compounds are those in which R1 represents hydrogen, methyl, ethyl, isopropyl, 2-methoxy-ethyl, allyl, propargyl or cyclopropyl, R2 represents hydrogen or methyl or R, and R2 together with the nitrogen atom to which they are attached represent 1-pyrrolidinyl, 4-morpholinyl or 1-imidazolyl, R3 represents methyl, R4 represents methyl and R5 represents hydrogen, and in which, if R1 represents propargyl, R2 preferably represents hydrogen.

Compounds to be particularly highlighted are those in which R1 represents hydrogen, methyl or ethyl, R2 represents hydrogen, R3 represents methyl, R4 represents methyl and R5 represents hydrogen.

Particularly preferred compounds are: 2-cyclopropylamino-4-dimethylformamidino-6-amino-s-triazine, 2-cyclopropylamino-4-dimethylformamidino-6-ethylamino-s-triazine, 2-cyclopropylamino-4-dimethylformamidino-6-methylamino-s-triazine, and 2-cyclopropylamino-4-dimethylformamidino-6-propargylamino-s-triazine.

The compounds of the formula I can be obtained by methods which are known per se, for example by (a) reacting a 2-cyclopropylamino-4,6-diamino-s-triazine of the formula II

in which Rl, R2 and R5 are as defined in formula I, with an amino-acetal of the formula III

alkyl - R3 CH - N (III) alkyl - 0 R4 in which R3 and R4 are as defined in formula I, or (b) reacting a 2-cyclopropylamino-4-formamidino-6-chloro-s-tnazine of the formula IV

in which R3, R4 and R5 are as defined in formula I, with ammonia or with a primary or secondary amine of the formula V

in which R, and R2 are as defined in formula I.

The above reactions (a) and (b) are preferably carried out in a solvent or diluent which is inert to the reactants, for example in aliphatic or aromatic hydrocarbons, halogenated hydrocarbons ethers or ethereal compounds or ketones.

A catalyst, for example p-toluenesulphonic acid can be added to the reaction mixture, but is not essential. The reaction temperatures are preferably between 30 and 1300C.

The starting materials of the formulae II and IV can be prepared in accordance with known processcs by replacing chlorine in chlorinated s-triazine derivatives by a corresponding amino group or by several corresponding amino groups. Some of the compounds of formula II are claimed in our Application No. 34793/77 (Serial No. 1587573). The manufacture of 2-diallylamino-4-amino-6-(N,N-dimethylformamidine)-s-triazine is described in U.S. patent specification 3,073,851.

Diamino- and triamino-s-triazines are described as chemosterilants for adult houseflies (MlJSCa nornesticn) in US patent specification 3,189,521. The chemosterilising action on insects of 2,4,6-triamino-s-triazine derivatives (melamine derivatives) is also described by S.

Nagasawa et al., Botyu-Kagaku 39 (4), 105 (1974). A.B. Borkovec and A.B. DeMilo [J.

Med.Chem. 10 (5), 457 (1967)] and G.C. LaBrecque, R.L. Fye, A.B. DeMilo and A.B.

Borkovec [J. Econ.Entomol. 61, (6), 1621 (1968)] also describe the chemosterilising action of, inter alia, 2-cyclohexylamino-4 ,6-diamino-s-triazine, 2-cyclohexylamino-4,6dihexylamino-s-triazine and 2,4,6-tris-cyclohexylamino-s-triazine, and the salts thereof, on adult houseflies (Musca domestica).

Surprisingly, it has now been found that the compounds of the formula I possess a marked larvicidal action on insect larvae, preferably on Diptera larvae. In contrast to the above mentioned insecticidal chemosterilants, the compounds of the formula I act on the developmental stages of the insects. The action consists in killing the freshly hatched larvae or preventing adults from hatching from the pupae. The mode of action of the compounds of formula I is not to be compared with that of classical insecticides, chemosterilants or juvenile hormone analogues.

The compounds of the formula I can be used in particular for controlling hygiene pests and animal ectoparasites of the order Diptera, and especially of the families: Culicidae, Simuliidae, Tipulidae, Muscidae and Calliphoridae.

The compounds of the formula I can be used without any additive or together with suitable carrier(s) and/or other additive(s). Suitable carriers and other additives can be solid or liquid and can be any conventionally used in the art of formulation of a larviadal insecticide, for example natural or regenerated substances, solvents and/or dispersants.

The compositions according to the invention can be manufactured in known manner by homogeneously mixing and/or grinding a compound of the formula I with a carrier, which can include a dispersant or solvent and which is inert to the active substance (Compound of formula I).

The active substances may be processed to the following formulations: Solid fonnulations: Dusts, tracking agents and granules (coated granules, impregnated granules and homogeneous granules), premix (feed additive).

Liquid formulations: a) active substance concentrates which are dispersible in water: wettable powders, pastes and emulsions; b) solutions: sprays (aerosols).

To manufacture a solid formulation (dusts, tracking agents), the active substance is mixed with a solid carrier. Suitable carriers are, for example: kaolin, talc, bolus, loess, chalk, limestone, ground limestone, attaclay, dolomite, diatomaceous earth, precipitated silica, alkaline earth silicates, sodium and potassium aluminium silicates (feldspar and mica), calcium and magnesium sulphates, magnesium oxide, ground synthetic materials, fertilisers, for example ammonium sulphate, ammonium phosphate, ammonium nitrate, urea, ground vegetable products, such as corn meal, bark dust, sawdust, nutshell meal, cellulose powder, residues of plant extractions, activated charcoal etc. These carriers can either be used singly or in admixture with one another.

Granules can be very easily manufactured by dissolving an active substance of the formula I in an organic solvent and applying the solution thereby obtained to a granulated mineral, for example attapulgite, SiO2, granicalcium, bentonite etc. and then evaporating the solvent.

Polymer granules can also be manufactured by mixing an active substance of the formula I with polymerisable compounds (urea/formaldehyde; dicyandiamide/formaldehyde; melamine/formaldehyde or others), whereupon a mild polymerisation is carried out that does not affect the active substances and in the process of which the granulation is carried out during the gel formation. It is more advantageous to impregnate finished, porous polymer granules (urea/formaldehyde, polyacrylonitrile, polyester or others) which have a specific surface area and a favourable predeterminable adsorption/desorption ratio, with the active substances, for example in the form of their solutions (in a low boiling solvent) and to remove the solvent. Polymer granules of this kind in the form of microgranules having preferably a bulk density of 300 g/litre to 600 g/litre can also be manufactured with the aid of atomisers.

It is also possible to obtain granules by compacting the carrier with the active substance and additive(s) and subsequently comminuting the product.

To these mixtures can also be added additives which stabilize the active substance and/or nonionics, anionics and cationics, which, for example, ensure a better wettability (wetting agents) and dispersibility (dispersants). Examples of suitable substances are: olein/chalk mixture, cellulose derivatives (methyl cellulose, carboxymethyl cellulose), hydroxyethyl glycol ethers of monoalkyl and dialkyl phenols having 5 to 15 ethylene oxide radicals per molecule and 8 or 9 carbon atoms in the alkyl moiety, ligninsulphonic acid, the alkali metal and alkaline earth metal salts thereof, polyethylene glycol ethers, fatty alcohol polyethylene glycol ethers having 5 to 20 ethylene oxide radicals per molecule and 8 to 18 carbon atoms in the fatty alcohol moiety, condensation products of ethylene oxide, propylene oxide, polyvinylpyrrolidone, polyvinyl alcohol, condensation products of urea and formaldehyde, and also latex products.

Water-dispersible concentrates, i.e. wettable powders, pastes and emulsifiable concentrates, are compositions which can be diluted with water to the desired concentration. They consist of active substance, carrier, optionally additive(s) which stabilize the active substance, surface-active substance(s) and anti-foam(s) and, if appropriate, solvent(s).

Wettable powders and pastes are obtained by mixing and grinding the active substance with dispersant(s) and pulverulent carrier(s) in suitable devices until homogeneity is attained. Suitable carriers are, for example, those already mentioned for the solid forms of application. In some cases it is advantageous to use mixtures of different carriers. Examples of dispersants are condensation products of sulphonated naphthalene and sulphonated naphthalene derivatives with formaldehyde, condensation products of naphthalene or naphthalene sulphonic acids with phenol and formaldehyde as well as alkali metal, ammonium and alkaline earth metal salts of ligninsulphonic acid, in addition, alkylaryl sulphonates, alkali metal and alkaline earth metal salts of dibutyl-naphthalenesulphonic acid, fatty alcohol sulphates such as salts of sulphated hexa-decanols, heptadecanols, octadecanols, and salts of sulphated fatty alcohol glycol ethers, the sodium salt of oleyl methyl tauride, ditertiary ethylene glycols, dialkyl-dilauryl ammonium chloride and fatty acid alkali metal and alkaline earth metal salts.

Suitable anti-foams are for example silicone oils.

The active substances is so mixed, ground, sieved and strained with the additive(s) mentioned above that, in wettable powders, the solid particle size of 0.02 to 0.04 mm and in pastes, of 0.03 mm, is not exceeded. Emulsifiable concentrates and pastes are manufactured by using dispersants, such as those referred to above, organic solvents, and water.

Examples of suitable solvents are: alcohols, dimethyl sulphoxide, and mineral oil fractions which boil between 120 and 350"C. The solvents must be virtually odourless and inert to the active substances.

Furthermore, the compositions according to the invention can take the form of solutions.

For this purpose the compound or compounds of the general formula I are dissolved in a suitable organic solvent or mixture of solvents. Aliphatic and aromatic hydrocarbons, chlorinated derivatives thereof, alkylnaphthalenes and mineral oils, singly or in admixture, can be used as organic solvents.

Formulations of the compounds of the formula I are described hereinafter. The parts denote parts by weight.

Dusts: The following substances are used to manufacture a) a 0.5% and b) a 2% dust: a) 0.5 part of active substance 99.5 parts of talc b) 2 parts of active substance 1 part of highly disperse silica 97 parts of talc.

The active substance is are mixed with the carrier and ground.

Tracking agents: 5 parts of active substance are mixed with 95 parts of carbonate of lime and ground to an average particle size of 801l.

Granules: 5 parts of active substance are dissolved in a solvent, e.g. methylene chloride, and mixed with 2 parts of polyethylene glycol ("Carbowax"; Registered Trade Mark) 91.5 parts of calcium carbonate are impregnated with the mixture and 1.5 parts of precipitated silica are admixed.

The solvent is subsequently evaporated.

Wettable ponder: 50 parts of active substance are mixed with 5 parts of a dispersing agent, e.g. sodium ligninsulphonate, 5 parts of a wetting agent, e.g. dibutylnaphthalene-sulphonic acid 10 parts of silica and 30 parts of China clay and the mixture is finely ground.

Emulsifiable concentrate: 20 parts of active substance are mixed with 20 parts of emulsifier, e.g. a mixture of alkylarylpolyglycol ether with alkylarylsulphonates, and 60 parts of solvent until the solution is completely homogeneous. By diluting this concentrate with water it is possible to obtain an emulsion of the desired concentration.

Premix (feed additive): 0.25 parts of active substance and 4.75 parts of secondary calcium phosphate, or China clay, "Aerosil" (Registered Trade Mark) or carbonate of lime are homogeneously mixed with 95 parts of an animal feed, e.g. poultry food.

Spray: The following constituents are used to manufacture a 2% spray: 2 parts of active substance 98 parts of kerosene.

Other biocidal active substances or agents can be admixed with the compositions described hereinabove. Thus in addition to the cited compounds of the general formula I, the compositions of the present invention can obtain, for example, insecticides to broaden the activity spectrum.

The compositions, or the active compounds contained therein, exert their inhibitory action therefore chiefly on the development of larvae or pupae of insects, preferably of the order Diptera.

EXAMPLE 1 2-Cyclopropylamino-4-N', N' -dimethylformamid ino-6-morpholino-s-triazine 20 g of 2-cyclopropylamino-4-amino-6-morpholino-s-triazine are suspended in 200 ml of benzene and the suspension is treated with 13 g of N,N-dimethylformamide-dimethyl acetal with the addition of 0.5 g of p-toluenesulphonic acid (as catalyst). The reaction mixture is refluxed for 10 hours. The solvent is then removed in vacuo and the residue is suspended in ether. The precipitated solid is recrystallised from isopropanol. Melting point: 1600-1620C.

The following compounds are prepared in accordance with the above procedure: No. Compound mp. in "C 1 2-cyclopropylamino-4-N' ,N '-dimethylforma- 152-153 midino-6-pyrrolidino-s-triazine 2 2-cyclopropylamino-4-N ,N'-dimethylforma- 169-170 midino-6-ethylamino-s-triazine 3 2-cyclopropylamino-4-N' ,N'-dimethylforma- 186-188 midino-6-methylamino-s-triazine 4 2-cyclopropylamino-4-N' ,N'-dimethylforma- 158-159 midino-6-allylamino-s-triazine 5 2-cyclopropylamino-4-N' ,N '-dimethylforma- 193-194 midino-6-isopropylamino-s-triazine 6 2-cyclopropylamino-4-N' ,N'-dimethylforma- 126 midino-6-propargylamino-s-triazine 7 2 ,6-bis-(cyclopropylamino)-4-N' ,N '-dimethyl- 220-223 formamidino-s-triazine 8 2-cyclopropylamino-4-N',N'-dimethyl 184-185 formamidino-6-imidazole-s-triazine 9 2-cyclopropylamino-4-N' ,N'-dimethyl 151-153 formamidino-6-(2-methoxyethylamino)-s-triazine 10 2-cyclopropylamino-4-N',N'-dimethylforma 132-134 midino-6-dimethylamino-s-triazine 11 2-cyclopropylamino-4-N',N'-dimethylforma- 96-98 midino-6-(N-methyl-N-ethylamino)-s-triazine 12 2-cyclopropylamino-4-N',N'-dimethylforma 196-198 midino-6-amino-s-triazine EXAMPLE 2 Action against Musca domestica 50 g of freshly prepared CSMA nutrient substrate for maggots are charged into beakers.

2.5 ml portions of a 1% acetonic solution of the respective active substance are pipetted onto the nutrient substrate present in the beakers. The substrate is then thoroughly mixed and the solvent subsequently allowed to evaporate.

Then 25 one-, two- and three- day-old maggots and approx. 50 eggs of Musca domestica are put into each of the beakers containing the treated nutrient substrate for testing with each active substance. After the maggots have pupated, the pupae are separated from the substrate by flushing them out with water and counted. The number of flies which have hatched out of the pupae is then counted after 10 days and any influence on the metamorphosis thereby determined.

The compounds of the formula I displayed good activity in this test.

EXAMPLE 3 Action against Lucilia sericata 1 ml of an aqueous solution containing 0.5% of active substance is added to 9 ml of a culture medium at 50"C. Then approx. 30 freshly hatched larvae of Lucilia sericata are added to the culture medium and the insecticidal action is determined by evaluation of mortality after 48 and 96 hours respectively. In this test, the compounds of the formula I act well against Lucilia sericata.

EXAMPLE 4 Action against A edges aegypti Active substance concentrations of 10, 5 and 1 ppm respectively are obtained by pipetting a specific amount of a 0.1% solution of the active substance in acetone onto the surface of 150 ml of water in each of a number of beakers. After the acetone has evaporated, 30 to 40 two-day-old larvae of Andes aegypti are put into each of the beakers containing the active substance solution. Evaluation of mortality is made after 1, 2 and 5 days respectively.

In this test, the compounds of the formula I exhibit good action against Aides aegypti.

WHAT WE CLAIM IS: 1. 2-Cyclopropylamino-4-formamidino-6-amino-s-triazine of the formula

wherein Rl represents a hydrogen, C1-C4-alkyl which is unsubstituted or substituted by Cl-C4- alkoxy; or represents a C3 or C4-alkenyl, C3 or C4-alkynyl, cyclopropyl, hydroxyl, methoxy or ethoxy, R2 represents hydrogen, methyl or ethyl, or Rl and R2 together with the nitrogen atom to which they are attached represent a 5- or 6-membered heterocyclic ring in which the nitrogen atom shown is the sole hetero-atom or which contain a further nitrogen atom or an oxygen atom, R3 represents methyl or ethyl, R4 represents methyl or ethyl, and R5 represents hydrogen or methyl.

2. Compounds according to claim 1 wherein Rl represents hydrogen, C1-C4-alkyl which is unsubstituted or substituted by C1-C4-alkoxy, or represents C3- or C4-alkenyl, C3- or C4-alkynyl, cyclopropyl, hydroxyl, methoxy or ethoxy; R2 represents hydrogen, methyl or ethyl, or Rl and R2 together with the nitrogen atom to which they are attached represent 1-pyrrolidinyl, 1-piperidinyl, 4-morpholinyl, 1-piperazinyl, or 1-(4-methyl)-piperazinyl; R3 represents methyl or ethyl; R4 represents methyl or ethyl and R5 represents hydrogen or methyl.

3. Compounds according to claim 1 wherein Rl and R2, together with the nitrogen atom to which they are attached, represent a 1-imidazolyl group and the other symbols are as defined in claim 2.

4. Compounds according to claim 1 in which Rl represents hydrogen, C1.4 alkyl which is unsubstituted or substituted by C14 alkoxy or represents C3 or C4-alkenyl, C3 or C4 alkynyl or cyclopropyl, or R1 and R2 together are as defined in claim 1.

5. Compounds according to claim 1 or 2 wherein Rl represents hydrogen, methyl, ethyl, isopropyl, 2-methoxy-ethyl, allyl, propargyl or cyclopropyl; R2 represents hydrogen or methyl or Rl and R2 together with the nitrogen atom to which they are attached represent 1-pyrrolidinyl or 4-morpholinyl; R3 represents methyl; R4 represents methyl and R5 represents hydrogen.

6. Compounds according to claim 5 wherein R, represents propargyl and R2 represents hydrogen.

7. Compounds according to claim 1 or 2 wherein R, and R2, together with the nitrogen atom to which they are attached, represent a 1-imidazolyl group and the other symbols are as defined in claim 5.

8. Compounds according to claim 4 wherein Rl represents hydrogen, methyl or ethyl; R2 represents hydrogen; R3 represents methyl; R4 represents methyl and R5 represents hydrogen.

9. 2-Cyclopropylamino-4-dimethylformamidino-6-morpholino-s-triazine.

10. 2-Cyclopropylamino-4-dimethylformamidino-6-amino-s-triazine.

11. 2-Cyclopropylamino-4-dimethylformamidino-6-ethylamino-s-triazine.

12. 2-Cyclopropylamino-4-dimethylformamidino-6-methylamino-s-triazine.

13. 2-Cyclopropylamino-4-dimethylformamidino-6-propargylamino-s-triazine.

14. Each of the compounds 1, 4, 5 and 7 to 11 specifically hereinbefore named in Example 1.

15. A process for the manufacture of 2-cyclopropylamino-4-formamidino-6-amino-striazines of the formula I according to claim 1, wherein a 2-cyclopropylamino-4,6-diaminos-triazine of the formula II

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (24)

1. **WARNING** start of CLMS field may overlap end of DESC **.

   150 ml of water in each of a number of beakers. After the acetone has evaporated, 30 to 40 two-day-old larvae of Andes aegypti are put into each of the beakers containing the active substance solution. Evaluation of mortality is made after 1, 2 and 5 days respectively.

   In this test, the compounds of the formula I exhibit good action against Aides aegypti.

   WHAT WE CLAIM IS: 1. 2-Cyclopropylamino-4-formamidino-6-amino-s-triazine of the formula

   wherein Rl represents a hydrogen, C1-C4-alkyl which is unsubstituted or substituted by Cl-C4- alkoxy; or represents a C3 or C4-alkenyl, C3 or C4-alkynyl, cyclopropyl, hydroxyl, methoxy or ethoxy, R2 represents hydrogen, methyl or ethyl, or Rl and R2 together with the nitrogen atom to which they are attached represent a 5- or 6-membered heterocyclic ring in which the nitrogen atom shown is the sole hetero-atom or which contain a further nitrogen atom or an oxygen atom, R3 represents methyl or ethyl, R4 represents methyl or ethyl, and R5 represents hydrogen or methyl.
2. 2. Compounds according to claim 1 wherein Rl represents hydrogen, C1-C4-alkyl which is unsubstituted or substituted by C1-C4-alkoxy, or represents C3- or C4-alkenyl, C3- or C4-alkynyl, cyclopropyl, hydroxyl, methoxy or ethoxy; R2 represents hydrogen, methyl or ethyl, or Rl and R2 together with the nitrogen atom to which they are attached represent 1-pyrrolidinyl, 1-piperidinyl, 4-morpholinyl, 1-piperazinyl, or 1-(4-methyl)-piperazinyl; R3 represents methyl or ethyl; R4 represents methyl or ethyl and R5 represents hydrogen or methyl.
3. 3. Compounds according to claim 1 wherein Rl and R2, together with the nitrogen atom to which they are attached, represent a 1-imidazolyl group and the other symbols are as defined in claim 2.
4. 4. Compounds according to claim 1 in which Rl represents hydrogen, C1.4 alkyl which is unsubstituted or substituted by C14 alkoxy or represents C3 or C4-alkenyl, C3 or C4 alkynyl or cyclopropyl, or R1 and R2 together are as defined in claim 1.
5. 5. Compounds according to claim 1 or 2 wherein Rl represents hydrogen, methyl, ethyl, isopropyl, 2-methoxy-ethyl, allyl, propargyl or cyclopropyl; R2 represents hydrogen or methyl or Rl and R2 together with the nitrogen atom to which they are attached represent 1-pyrrolidinyl or 4-morpholinyl; R3 represents methyl; R4 represents methyl and R5 represents hydrogen.
6. 6. Compounds according to claim 5 wherein R, represents propargyl and R2 represents hydrogen.
7. 7. Compounds according to claim 1 or 2 wherein R, and R2, together with the nitrogen atom to which they are attached, represent a 1-imidazolyl group and the other symbols are as defined in claim 5.
8. 8. Compounds according to claim 4 wherein Rl represents hydrogen, methyl or ethyl; R2 represents hydrogen; R3 represents methyl; R4 represents methyl and R5 represents hydrogen.
9. 9. 2-Cyclopropylamino-4-dimethylformamidino-6-morpholino-s-triazine.
10. 10. 2-Cyclopropylamino-4-dimethylformamidino-6-amino-s-triazine.
11. 11. 2-Cyclopropylamino-4-dimethylformamidino-6-ethylamino-s-triazine.
12. 12. 2-Cyclopropylamino-4-dimethylformamidino-6-methylamino-s-triazine.
13. 13. 2-Cyclopropylamino-4-dimethylformamidino-6-propargylamino-s-triazine.
14. 14. Each of the compounds 1, 4, 5 and 7 to 11 specifically hereinbefore named in Example 1.
15. 15. A process for the manufacture of 2-cyclopropylamino-4-formamidino-6-amino-striazines of the formula I according to claim 1, wherein a 2-cyclopropylamino-4,6-diaminos-triazine of the formula II

    in which Rl, R2 and R5 are as defined in formula I, is reacted with an amino-acetal of the formula III

    alkyl R3 CH-N alkyl-O R4 in which R3 and R4 are as defined in formula I.
16. 16. A process according to claim 15, substantially as described in Example 1.
17. 17. A 2-cyclopropylamino-4-formamidino-6-amino-s-triazine prepared by a process claimed in claim 15 or 16.
18. 18. An insecticidal composition comprising a 2-cyclopropylamino-4-formamidino-6amino-s-triazine claimed in any one of claims 1 to 14 and 17 and a carrier.
19. 19. A composition according to claim 18 in the form of a dust, tracking agent, granules, wettable powder, emulsifiable concentrate, animal feed additive or spray.
20. 20. A method of preventing the development of adult insects from larvae or pupae, which comprises applying to the larvae or pupae a 2-cyclopropylamino-4-formamidino-6amino-s-triazine claimed in claim 1 or 2.
21. 21. A method according to claim 20 wherein the insects are of the order of Diptera.
22. 22. A method according to claim 21 wherein the insects are of the families Culicidae, Simuliidae, Tipulidae, Muscidae and Calliphoridae which belong to the order Diptera.
23. 23. A method according to claim 20, 21 or 22 wherein a compound claimed in any one of claims 3, 7, and 10 to 14 is applied.
24. 24. A method according to claim 20, 21 or 22 wherein a compound claimed in any one of claims 4, 5, 6, 8 and 9 is applied.