CH652889A5 - HERBICIDES. - Google Patents

Description

The present invention relates to new herbicide compounds and, more particularly 60, new sulphides and bisulfides of formamide and thiocarbamoyl-guanidines having high herbicidal activity, as well as the method of preparing them and their use.

A limited number of formamide bisulphides are known from the literature, however no herbicidal properties have ever been recognized to these compounds.

P.K. Srivastrava et al. have prepared, for purely academic purposes, the following formamide bisulfides in the form of bromohydrates:

3

652 889

C6H5,

\ / H

H

C6 "S

the general formula I and thiocarbamoyl-guanidine having the general formula II:

N 2HSr ii

C., CV

/ \ / \

(P.K. Srivastrava et al., Tetrahedron Letters 23, 2725, 1968)

R

\

NU

C <Hs s-s

NH

C6H5

N

II

C

/

(THE)

R - N

CfiVCH2

\

/

CH2-C6H5

(S)

n

S 11 / \ / \

M S-S Nil,

. 2IIBr (P.K. Srivastrava et al., J. Ind. Chem. Soc. 40, 803, 1963)

6 5

N

C6H5

N

II

C

2HBr

/ \ / \

HH S-S NH

/

(P.K. Srivastrava et al., Indian J. Chem. 1, 354, 432, 1963)

R \

N

II

1 / C \

R - N

N - R

R

(II)

- c - n - r

The l2

r s r

CH,

CH.

However, analytical data for the characterization of the above three compounds are not reported, probably because, given their instability, they cannot be isolated as free bases.

Similarly, only a limited number of derivatives belonging to the class of thiocarbamoyl-guanidines are known from the technical literature. Herbicide properties have never been recognized in the past even in this class of compounds.

Held, Gross and Schubert [Zeitschrift der Chemie 13, 341 (1973)] prepared, by oxidation of N, N-dimethyl - N'-phenyl-thiourea with thionyl chloride, N ', N'-dimethyl-N2, N3-di-phenyl-N3- [N, N-dimethyl-thiocarbamoyl] -guanidine having the formula:

C6H5

N

h3c-n

C6H5

CH S = C-N (CII3> 2

/ \ /

[No.

In both formulas (I) and (II):

30 R = a phenyl optionally substituted by one or more halogen atoms, one or more alkyl or haloalkyl groups having from 1 to 3 carbon atoms;

R1 and R2 (same or different from each other) = C1-C3 alkyl, C1-C3 alkoxy, or

.35 R1 and R2 together form an alkylidene chain having 4 or 5 carbon atoms possibly interrupted by heteroatoms;

n = 1 or 2;

provided that, if in formula II R1 = R2 = CH3, R is a substituted phenyl.

40 The compounds of formula (I) and (II), even in the case where in formula (II) R1 = R2 = CH3 if R = unsubstituted phenyl, have herbicidal activity against both monodicotyledons and dicotyledons and can be advantageously used, as such or in the form of suitable compositions, in the fight against weeds.

Another object of the present invention is in fact to provide a method for combating weeds by using the compounds of formula (I) and (II) and the relative compositions.

The preparation of the compounds of formula (I) and (II), which represents a further object of this invention, is carried out according to the processes described below.

The compounds of general formula (I) are prepared by oxidation of trisubstituted thioureas (III) in the presence of an organic base (reaction a), thus obtaining the compounds of formula (I), in which 55 n = 2 (bisulfides), from which, by desulphurization in the presence of triphenyl-phosphine (reaction b), the corresponding sulphides are obtained. The same compounds (monosulphides) can also be obtained by reacting a trisubstituted thiourea (III) with an appropriate imidoyl chloride (IV) in the presence of an acceptor base of 60 hydrogen halide (reaction c).

Srivastrava et al., [J. Ind. Chem. Soc. 40, 803 (1963)] prepared unsubstituted thiocarbamoyl-guanidine derivatives on the nitrogen atom in position 1 and on the nitrogen atom of the 65 thiocarbamoyl group, in the form of bromohydrates.

We have now found, and this constitutes the aim of the present invention, having formamide sulphides and bisulfides

652 889

4

S R "

The /

a) R-NH-ON

(III) ^ R2

oxidising

S-S

R

N

II

\

N-R

i2

(I, n = 2)

b) (X, n = 2) + (C6H5) 3P

C)

r

R

(III) + R - N - C - N

, /

V

->. (1, n = l) + '(C6H) P = S

(IV) - ^ 22 "(I> n = 1)

The reaction a) is carried out by oxidizing the thiourea (II) in the presence of an organic base and in an inert solvent. As an oxidizing agent it is possible to use, for example, a halogen such as bromine and iodine (Bt2, J2), while a tertiary amine such as triethyl- or tributyl-amine can be used as an organic base.

Excellent results are obtained by using methylene chloride (CH2CI2) or chloroform (CHCI3) as a solvent.

Under the conditions described above, the reaction takes place at room temperature and in very short times. At the end of the reaction the mixture is washed with water and anhydrified, and the solvent is evaporated. The obtained product can be used as such, or it can be crystallized from apolar solvents.

The reaction b) can be advantageously carried out by reacting equimolar quantities of bisulphide (obtained from reaction a) and of triphenyl-phosphine, in diethyl ether at about 0 ° C.

The triphenyl phosphine sulphide thus obtained precipitates and is separated by filtration at the end of the reaction. The reaction mixture is treated according to normal laboratory techniques and the formamide sulphide thus obtained is purified by crystallization from hydrocarbons.

The reaction c) leads directly to the obtainment of formamide sulphides without preliminary preparation of the corresponding bisulphides.

The reaction is carried out in an aprotic solvent and in the presence of a halogen hydric acid acceptor base.

An advantageous method for carrying out the aforementioned reaction is to add a solution of the thiourea (III) derivative and a slight excess of the base (tertiary amine) in methylene chloride to the imidoyl chloride (IV) solution in the same solvent.

The mixture is stirred at room temperature and the reaction takes place in a short time.

The product is then isolated with normal laboratory techniques.

The preparation of the compounds of general formula (II) is carried out by reacting a sulphide or disulfide of formamide (I) with a catalytic amount of a strong anhydrous acid (reaction d)

\

d)

/ \ -N (SK N-

(THE)

-> (II)

50 The reaction d) is preferably carried out by adding a catalytic quantity of an acid having sufficient strength to salify the basic groups of the sulfide or bisulphide of formula (I), to a solution of the latter in an aprotic polar solvent such as chloroform (CHCl3).

55 A strong halogen anhydrous acid or a trialoacetic acid can be used as a strong acid.

The reaction rate depends not only on the nature of the compound of formula (I) which is made to react, but also on the quantity of acid used.

60 For quantities of acid equal to 0.1 equivalent per mole of compound of formula (I), the reaction ends, even at room temperature, within a few minutes.

Once the reaction has taken place, the chloroform solution is washed with a saturated aqueous solution of 65 sodium bicarbonate (NaHCCb) and then anhydrified. The solvent is then evaporated under vacuum, thus obtaining as a residue the corresponding compound of formula (II), which can be subsequently purified by crystallization.

5

652 889

The process for the preparation of the compounds having the general formulas (I) and (II) can be summarized as reported in the following scheme 1.

Scheme 1

s r '

The ./

r-nii-c-n

(III) ^ R2

<D

oxidising

>: (I, n = 2)

(III) + R-N »C-N

CI R

I / ©

(IV)

\

basis

R

©

(C6HsY

-> (l, n = 1)

H

(II)

The compounds according to the formulas (I) and (II) reported in the following Table 1 have been prepared according to the processes described herein.

TABLE 1

Compounds having the formulas

\

/ "

N

11

C .C

1 / ns) / \ 1

R -N n N-R

I2 I2

R R

(THE)

\

N - C - N - R

, / I II l2

R -N

R S R

(Ii)

Formula

Compound No.

n

R

R1

R2

Elemental analysis (° 7o) (1) Value Theoretical NMR value found (6, ppm)

(2)

mp

(° C)

(3)

IR

(Cm-1)

Raw formula P.M.

THE

1

1

4-CH3-C6H4

i C3H7

i C3H7

C 72.05 H 9.07 N 12.00

72.45 8.78 10.35

7.3-6.5 (m) 4-3.4 (q) 2.3 (s) 1.07-0.97 (d)

1610; 1590 1360-1370

C28H42N4S 466.74

THE

2

2

4-Cl-C6H4

ch3

ch3

C 50.58 H 4.72 N 13.11

50.28 4.56 13.01

ci8h2on4s2Cl2 427.42

THE

3

2

4-CI-QH4

ch2-CH2-O-CH2-ch2

C 51.66 H 4.73 N 10.95

51.66 4.71 11.06

150-152

C22H24N4S202C12 511.50

652 889

6

TABLE 1 (continued)

Formula

Compound No.

n

R

R1 R2

Elemental analysis (%) (1) Value Theoretical NMR value found (ô, ppm)

(2)

mp

(° Q

(3)

IR

(Cm "1)

Raw formula P.M.

THE

4

2

4-CI-C6H4

-CH2- (CH2) 3-CH2-

C 56.79 H 5.56 N 11.04

55.52 5.50 11.14

105-107

C ^ NÄCfe 507.55

THE

5

2

3,4-Cl2-CfiH3

-CH2- (CH2) 3-CH2-

C 50.00 H 4.55 N 9.72

49.07

4:41

9:42

136-138

C24H26NÄCI4 576.44

THE

6

2

3,4-Cl2-C6H3

i C3H7 i C3H7

C 51.32 H 5.63 N 9.21

50.32 5.46 8.21

130-132

C26H34N4S2CI4 608.53

THE

7

1

3.4-C12-QH3

-CH2- (CH2) 3-CH2-

C 52.95 H 4.81 N 10.29

54.78 4.86 9.46

133-136

1590-1560 1370-1110

C24H26n4SC14 544.38

THE

8

1

3.4-C12-C6H3

i C3H7 i C3H7

C 54.17 H 5.94 N 9.72

55.63 5.73 8.45

7.3-6.57 (m)

4.0-3.3 (q) 0.95-107 (d)

160-165

1610-1570-1360

C24H34N4SCI4 576.46

THE

9

2

3-CF3-C6H4

ch2-CH2-O-CH2-ch2

S 11.08 N 9.68

11.15 9.32

114-115

C24H24F6N402S2 578.59

THE

10

2

4-C1-C6H,

i C3H7 i C3H7

C 58.09 H 6.37 N 10.42

57.70 6.77 10.48

156-158

c26H34N4S2C12 537.62

THE

11

1

4-Cl-C6H4

ch3 ch3

C 54.68 H 5.1 N 14.17

54.64 4.9 14.42

107-108

1610-1590-

1575

1080

ci8h2on4SCl2 595.36

THE

12

1

4-Cl-C6H4

-CH2- (CH2) 3-CH2-

C 60.62 H 5.93 N 11.78

62.87 5.84 9.67

146-151

1695-1590 1575-1370

CmH ^ SCIz 475.49

THE

13

1

4-Cl-C6H4

i c3h7 i C3H7

C 61.77 H 6.78 N 11.08

63.49 6.90 9.33

159-165

1600-1590 1570-1360

C26H36N4SC12 505.56

THE

14

2

3,4-Cl2-C6H3

CH2-0-CH2-CH2-CH2

C 45.52 H 3.82 N 9.65

44.63 3.68 9.4

123-125

C22H22N4S202C14 580.38

THE

15

2

3,4-Cl2-C6H3

ch3 ch3

C 43.54 H 3.62 N 11.26

43.68 3.55 11.15

69-71

ci8hi8n4s2clj 495.8

THE

16

1

3,4-Cl2-C6H3

ch3 ch3

C 46.57 H 3.9 N 12.07

48.86 4.00 10.95

7.35-645 (6H, m) 2.73 95-97 (12H, s)

ci8hi8n4sclt 464.25

THE

17

1

C6H5

ch3 ch3

C 66.22 H 6.79 N 17.16

66.2 6.8 17.25

7.4-6.6 (10H, m) 2.68 100-102 (12H, s)

1620.1585 1300, 750 690

cish ^ nts 326.47

7

652 889

TABLE 1 (continued)

Formula

Compound No.

n

R

R1

R2

Elemental analysis (%) (1) Value Theoretical NMR value found (6, ppm)

(2)

mp

(° c)

(3)

IR

(Cm " ')

Raw formula P.M.

THE

18

2

C6H5

ch3

ch3

C 60.3 H 6.2 N 15.65

60.45 6.2 15.65

2.9 (12H, s)

56-60

1610, 1585, 1260, 1100, 920, 830, 765, 698

Ci8H22N4S2 357.47

THE

19

2

4-CH3-QH4

i C3H7,

i C3H7

C 67.42 H 8.49 N 11.23

67.53 8.72 11.32

114-119

-

c28h42n4s2 498.80

THE

20

2

3-CF3-C6H4

ch3

ch3

S 12.96 N 11.33

12.46 11.39

oil

C2oH2oF6N4S2 494.51

THE

21

2

3-CF3-QH4

-CH2- (CH2) 3-CH2-

S 11.16 N 9.75

10.23 9.73

oil

q26h28f6n & 574.68

THE

22

2

3-cf3-c6h3

i C3H7

ÌC3H7

S 10.57

10,67

111-112

cmh36f6n4s2 606.72

THE

23

1

3-CF3-QH4

CH3

ch3

7.45-6.8 (m) 2.65 (s)

96-100

1600, 1590 1575, 1370 1320, 1210

C20H18N4F6S 462.45

THE

24

1

3-CF3-QH4

-CH2- (CH2) 3-CH2-

F 21.01 N 10.33

20.10 11.22

oil

c26h26f6n4s 542.58

THE

25

1

3-cf3-C6H4

ÌC3H7

i C3H7

130-133

1605.1565, 1370, 1360, 1320, 1255, 1220

II

26

3,4-Cl2-C6H3

ch3 ch3

C 46.57 H 3.88 n 12.08

46.08 3.76 11.81

125-127

-

c18h18n4scu

463.8

II

27

C6H5

ch3 ch3

C 66.2 H 6.8 n 17.15

66.55 6.85 17.2

7.53-6.6 (10H, m) 2.9 (6H, s) 119-120 2.53 (6H, s)

1625, 1580, 1300

1080, 765, 695

ci8H22n4s 326.47

II

28

4-CH3-QH4

CH2-CH2-O-CH2-CH2

C 65.72 H 6.89 n 12.74

65.2 6.95 13.01

142-145

C24N30N4SO2 438.59

II

29

4-CH3-C6H4

-CH2- (CH2) 3-CH2-

C 71.85 H 7.88 n 12.89

68.98 7.68 12.82

193-197

c26h34n4s

434.65

II

30

4-CH3-QH4

ch3 ch3

C 67.75 H 7.39 n 15.8

66.99 7.33 16.1

170.5 to 172.5

c20h26N4S 354, 52

II

31

4-There-QH4

ch3 ch3

C 54.68 H 51 N 14.17

54.46 4.97 14.22

161-163

ci8H20N4SCl2 396.36

II

32

4-Cl-C6H4

-CH2- (CH2) 3-CH2-

C 60.62 H 5.93 N 11.78

60.62 5.99 11.83

186-189

c24h28n4sc12

475.49

II

33

4-Cl-C6H4

CH2-0-CH2-CH2-CH2

C 55.12 H 5.04 N 11.69

53.29 4.86 11.22

189-194

C22H24N4S02Cl2 479.41

652 889

8

TABLE 1 (continued)

Formula

Compound No.

R

R1 R2

Elemental analysis (%) (1) Value Theoretical NMR value found (8, ppm)

(2)

mp

(° C)

(3)

IR

(Cm "1)

Raw formula P.M.

II

34

3-CF3-C6H4

CH2-0-CH2-CH2-CH2

N 10.25 F 20.86

9.86 20.66

174-175

546.52

II

35

3-CF3-C <SH4

ch3 ch3

S 6.93

6.72

oil

462.45

II

36

3-CF3-C6H4

-CH2- (CH2) 3-CH2-

S 5.91

5.59

142-146

542.58

II

37

3,4-Cl2-C6H4

CH2-0-CH2-CH2-CH2

C 48.19 H 4.04 N 10.21

47.29 3.96 9.99

153-155

C22H22N402Cl4 548.32

II

38

3,4-Cl2-C6H3

-CH2- (CH2) 3-CH2-

C 52.95 M 4.81 N 10.29

52.08 4.75 10.08

156-160

GwHÄSCl 544.38

The compounds having the general formulas (I) and (II) are endowed with a high herbicidal activity exerted against monocotyledons and dicotyledons.

Table 2 shows the data relating to the activity of some representative compounds, obtained as described in example 5.

Herbicidal activity has been examined on the following weeds:

monocots

A = Echinochloa crusgalli

B = Oat fatua

C = Lolium italicum

D = Sorghum spp.

E = Setaria glauca

F = Digitaria sanguinalis

G = Alopecurus myosuroides

H = Panicum dichotomiflorum

I = Festuca pratense

J = Bromus sterilis

K = annual Poa

dicotiledoni

L = medium Stellaria

25 M = Ipomea purpurea

N = Vigna sinensis

O = Rumex acetosella

P = Galinsoga parviflora

Q = Convolvolus sepium

3rd R = Convolvolus ariensis

S = Géranium dissect

T = Sida spinosa

U = Brassica

V = Gypsophila muralis

W = Galium aparine.

The herbicidal activity data reported in table 2 are expressed using a scale of values ranging from 0 (no herbicidal activity, plant growth equal to that of the witness) to 4 (death of the plant or total arrest of its growth).

Table 2

Compound N °

Treatment

Dose

monocots

dicotiledoni

(see Table 1)

(Kg / ha)

TO

B

C

D

IS

F

G

H

THE

J

K

L

M

N

OR

P

Q

R

S

T

U

V

W

2

Pre-Emergency

6

4

4

4

4

4

4

4

4

4

4

4

Post-Emergency

2

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

11

Post-Emergency

2

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

15

Pre-Emergency

6

3

4

3

3

4

4

4

4

Post-Emergency

6

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

16

Post-Emergency

6

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

17

Post-Emergency

6

2

2

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

20

Post-Emergency

2

4

3

3

4

3

2

4

4

2

26

Pre-Emergency

6

2

4

4

4

4

4

4

4

4

Post-Emergency

6

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

35

Pre-Emergency

6

4

3

3

Post-Emergency

2

4

4

3

4

4

4

4

4

4

4

4

9

652 889

Depending on the particular compound used, the best effectiveness of the herbicidal activity is obtained by application in the pre-emergence or post-emergence phase, i.e. when the weeds have not yet emerged from the soil or when they are already.

The herbicide compounds according to the present invention have also been shown to be selective towards useful crops, such as wheat, corn, soy and cotton.

For agricultural applications, the active compounds are distributed on the soil as such or, preferably, in the form of suitable compositions consisting of one or more compounds of formula (I) as the active principle and one or more appropriate supports.

Suitable compositions include wettable powders, liquid pastes, granular formulations etc.

Suitable substrates include, depending on the type of composition, silica, kaolin, fossil flour, bentonite, pumice, organic solvents, water, etc.

The compositions can also include additives such as surfactants, emulsifiers, thickeners etc.

In me. Cutcheons - Detergents and Emulsifiers - North American and International Editions, 1977 Annual. Me. Cutcheons Pubi. Co., Glen Rock, New Jersey (U.S.A.) 'is a list of media and additives.

Said compositions are prepared according to procedures commonly adopted in practice.

Other active ingredients may also be included in the compositions, such as fertilizers, insecticides or fungicides. The amount of active substance (compounds of formula I and II) that must be distributed on the soil depends on various factors,

such as environmental conditions, the type of agricultural cultivation to be protected from weeds, the type of composition and the particular active principle.

Generally, quantities of compounds of formula (I) and (II) comprised between 1 and 6 kg / ha are suitable for obtaining good results in the fight against weeds, the preferred quantity being between about 2 and 3 kg / ha.

The following examples are given to better illustrate the present invention.

Example 1

Preparation of N'.N'-dimethyl-N ^ phenyl-formamide amine disulfide (compound N ° 18, Table I). (Reaction a).

A chloroform solution of iodine (5.2 g in 100 ml) is added dropwise and under stirring to a solution of N, N-dimethyl-N'-phenyl-thiourea (5 g, 0.0277 moles) and triethylamine ( 7.5 ml) in chloroform (50 ml).

The addition is carried out until the iodine color remains constant in the reaction mixture.

After 15 minutes the stirring is suspended, the reaction mixture is washed repeatedly with water (750 ml) and anhydrified with anhydrous Na2SO4. After separation of the solvent, a yellow oil is obtained which, crystallized from n-hexane, provides 4 g of the desired product.

Example 2

Preparation of N'.N'-dimethyl-np-phenyl-formamide sulphide (Compound N ° 17, Table I). (Reaction b).

To a solution of N'-N'-dimethyl-N2-phenyl-formamide amine disulfide prepared as described in example 1 (350 mg) in diethyl ether (2 ml), 256 mg of triphenyl-phosphine are added under stirring, while cool from the outside with water or ice bath.

At the end of the reaction (about 3 hours), a white precipitate of triphenyl phosphine sulphide is separated by filtration at 0 ° C.

The solvent is then removed under vacuum and the residue, crystallized from n-hexane, provides 112 mg of the desired product free of impurities.

Example 3

Preparation of N'.N'-dimethyl-N ^ phenyl-formamide amine sulfide. (Compound N ° 17, Table I). (Reaction c).

A solution of N, N-dimethyl-N'-phenyl-thiourea (0.9 g) and phosgene (COCI2) (2 g), in methylene chloride, is stirred for 8 hours at room temperature. After elimination of the solvent under vacuum, the residue (imidoyl chloride) is dissolved in a solution of triethylamine (0.7 ml) and anhydrous methylene chloride (20 ml).

A solution of N, N-dimethyl-N'-phenyl-thiourea (0.9 g) and triethylamine (0.7 ml) in methylene chloride (20 ml) is added drop by drop, under stirring and at room temperature, to the above solution.

After stirring for 8 hours, the reaction mixture is washed with water, dried with anhydrous sodium sulphate, and the solvent is eliminated under vacuum. The residue from petroleum ether is crystallized, thus obtaining 1.4 g of the desired product (yield = 86%).

Example 4

Preparation of N'.N'-dimethyl-N ^ N ^ diphenyl-N ^ KN.N - dimethyl) -thiocarbamoyl] guanidine (Compound N ° 27, Table I). (Reaction d).

43 the trifluoroacetic acid are added to a solution of N ', N-dimethyl-N2-phenyl-formamide amine disulfide (2 g, 5.58 l 3 moles) obtained as described in Example 1, in chloroform (200 ml ).

The reaction mixture is left to rest for 15 minutes at room temperature, then washed with a saturated solution of NaHCCb and anhydrified with anhydrous Na2SO4.

After elimination of the solvent by evaporation under vacuum, the residue is crystallized from n-hexane / benzene (70:30).

1.3 g of the desired product are obtained (yield = 71%).

Example 5 Determination of the herbicidal activity.

Some pots are prepared (top diameter = 10 cm, height = 10 cm) by introducing sandy soil, then one or more of the weeds listed on pages 24 and 25 are sown in each pot. Water is added to each pot in the quantity necessary to cause good sprouting of seeds. The vases are divided into three series.

The first series is not treated with any herbicide and is used as a witness (control).

The second series is treated, after 1 day from sowing, with a hydroacetonic dispersion (20% in vol./voi.) Of the compounds of the invention, in order to determine the herbicidal activity in the pre-emergency phase.

The third series is treated, 15 days after sowing (i.e. when the seedlings have already reached a height of 5-10 cm, depending on the species), with a hydroacetonic dispersion (20% in vol./voi.) of the compounds of the invention for the purpose of determining the herbicidal activity in the post-emergence phase.

All vessels are kept under observation in a conditioned environment, at temperatures between 15 and 24 ° C, relative humidity = 70%, photoperiod = 12 hours, light intensity = 2500 lux.

Every two days the plants are evenly bathed with water to ensure a sufficient degree of humidity for good plant growth.

28 days after the treatment checks are carried out to establish the vegetative stage of the plants; the results of these checks are expressed according to a scale of values that goes from 0 (growth equal to that of the witness) to 4 (complete arrest of the growth or complete death of the plants).

5

I

15

20

25

30

35

40

45

50

55

60

65

V

Claims (8)

652 889 1 S / \ (III) R in which R = phenyl optionally substituted by one or more halogen atoms, one or more alkyl or haloalkyl groups having from 1 to 3 carbon atoms; R1 and R2 - equal or different from each other - = C-C3 alkyl, C1-C3 alkoxy, or R1 and R2 together form an alkylidene chain having 4 or 5 carbon atoms, possibly interrupted by a heteroatom, provided that, if in the formula (II) R1 = R2 = CH3, R is a substituted phenyl; n = 1 or 2. The compounds according to claim 1, having the formula (I), wherein n = 1. 2 CLAIMS 1. Herbicide compounds having the general formulas: \ R / « c A A N THE! c © (S) n N - R R \ fact that a compound of formula (I) wherein n = 2, is treated with triphenyl-phosphine in diethyl ether at 0 ° C. , 9. Process for the preparation of compounds of formula (II) according to claim 1, characterized in that a 3. The compounds according to claim 1, having the formula (I), where n = 2. The compounds according to claim 1, having the formula (II). The compounds according to one of claims 1 to 3, wherein R1 and R2 - equal or different from each other - = C1-C3 alkyl. 5 compound of formula (I) wherein n = 1 or 2 of claim 1, is treated with a strong anhydrous acid in an aprotic polar solvent at room temperature. 10. Process according to claim 7, characterized in that bromine -Br2- or iodine -J2- is used as oxidant. 10. Process according to claim 9, characterized in that a halogenric or trialoacetic acid is used as strong anhydrous acid. 12. Process according to claim 7 or 9, characterized in that methylene chloride i5 (CH2CI2) or chloroform (CHCI3) is used as the solvent. 13. Process for the preparation of herbicide compounds according to claim 1, having the formula (I) wherein n = 1, characterized in that a trisubstituted thiourea of formula: N II C 20 R-N R / \ ÖD N - C - N - R R - UH - C - N, The compounds according to one of claims 1 to 4, wherein R1 and R2 together represent the -CH2- (CH2) 3-CH2 group or the -CH2-CH2-O-CH2-CH2 group. 7. Process for the preparation of herbicide compounds of formula (I) wherein n = 2 according to claim 1, characterized in that a trisubstituted thiourea of formula wherein R, R1 and R2 have the meaning specified in claim 1, is made reacting, reaction c, in the presence of a law-30 or excess of an organic base and in an inert solvent, with an imidoyl chloride of formula: 35 R - N CI I C - N XR2 (IV) 40 wherein R, R1 and R2 have the meaning indicated in claim 1, according to the scheme: c) (III) + (IV) - »► (I, n = 1). basis 14. Herbicide compositions characterized in that they have, as an active principle, one or more compounds of general formula (I) or (II) according to claim 1. 15. Method to combat infestations with 50 monocotyledons and dicotyledons in the pre-emergence or post-emergence phase emergency, consisting in spreading on the ground, in quantities ranging from 1 to 6 kg / ha, one or more of the herbicide compounds corresponding to the general formulas (I) and (II) according to claim 1. 55 • R - NH - C - N (III) * R wherein R, R1 and R2 have the meaning reported in claim 1, it is treated with an oxidant in the presence of a base and in an inert solvent. 8. Process for the preparation of compounds of formula (I) wherein n = 1 according to claim 1, characterized by