Abstract:
Novel substituted thiomethyl aryl ureas having the formula ##STR1## wherein R is selected from the group consisting of alkyl of 1 through 12 carbon atoms; alkenyl containing 2 through 4 carbon atoms; ##STR2## wherein R 2  is alkyl containing 1 through 4 carbon atoms; ##STR3## WHEREIN R 3  is alkyl containing 1 through 6 carbon atoms and m is 1 or 2; ##STR4## wherein Z is --Cl, --Br, --I, or CF 3 , and n is a whole number from 1 to 3 inclusive; ##STR5## wherein Y is --H, --Cl, --Br, or --I, and n is 1 or 2, and ##STR6## --X is --H or --Cl. The compounds are useful as herbicides.

Description:
This is a continuation of application Ser. No. 540,374 filed Jan. 13, 1975, now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates to certain novel compositions and to their use as herbicides. More particularly, the invention relates to certain substituted thiomethyl aryl ureas, and the use of these materials as herbicides. 
     SUMMARY OF THE INVENTION 
     The compounds of the invention have the formula ##STR7## wherein R is selected from the group consisting of alkyl of 1 through 12 carbon atoms; alkenyl containing 2 through 4 carbon atoms; ##STR8## wherein R 2  is alkyl containing 1 through 4 carbon atoms; ##STR9## WHEREIN R 3  is alkyl containing 1 through 6 carbon atoms and m is 1 or 2; ##STR10## wherein Z is --Cl, --Br, --I, or --CF 3 , and n is a whole number from 1 to 3 inclusive; ##STR11## wherein Y is --H, --Cl, --Br, or --I, and n is 1 or 2, and ##STR12## --X is --H or --Cl. The most preferred compounds of the invention are those, of the formula indicated, wherein R is alkyl of 1 through 8 carbon atoms and X is --H. 
     In general, the method of the invention comprises contacting undesired vegetation or a locus to be protected with an effective or herbicidal amount of a composition having the formula above indicated. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In order to describe the invention with greater particularity, reference is made to the following non-limiting examples. Those skilled in the art will readily recognize the generality of the procedures employed, and will be able thereby to prepare compounds within the scope of the invention which are not specifically described. 
     EXAMPLE I 
     Preparation of N-(tert.-butylthiomethyl)-N-methyl amine hydrochloride 
     Two hundred ml. of acetonitrile and 6.45 g. (0.05 mole) of 1,3,5-trimethylhexahydro-s-triazine are charged to a 500 ml. 3-neck round bottom flask equipped with a stirrer, thermometer and dropping funnel. The mixture is stirred and cooled to -30° C. with a dry ice/acetone bath. Six grams of hydrogen chloride gas are added, followed by slow addition of 13.5 g. (0.15 mole) of tert.-butyl mercaptan dissolved in 50 ml. of acetonitrile. The mixture is then allowed to warm to room temperature and stand overnight. 
     The following day, the solvent is removed in vacuo. The product is then crystallized by addition of 500 ml. of cold diethyl ether. The solid is collected by filtration, washed with 200 ml. diethyl ether, and dried in a vacuum dessicator. A yield of 23.6 g. (92.8% of theory) of the title compound is obtained. 
     EXAMPLE II 
     Preparation of N-methyl-N-(tert.-butylthiomethyl)-N&#39;-(3-trifluoromethylphenyl) urea 
     Two grams of the product of Example I (0.0118 mole), 2.2 g. (0.0118 mole) of 3-trifluoromethylphenylisocyanate, and 100 ml. of acetonitrile are combined in a 250 ml. Erlenmeyer flask. The mixture is magnetically stirred, and 1.9 g. (0.0118 mole) of triethylamine are then added. The resulting mixture is stirred at room temperature for one hour and then poured into 300 ml. of ice water. The crystalline product is collected by filtration and dried to yield 2.0 g. (53% of theory) of the title compound, mp = 96°-99° C. Structure is confirmed by IR and NMR. 
     EXAMPLE III 
     Preparation of N-methyl-N-ethylthiomethylamine hydrochloride 
     Two hundred ml. of acetonitrile, 6.45 g. (0.05 mole) of 1,3,5-trimethylhexahydro-s-triazine; 9.3 g. (0.15 mole) ethyl mercaptan and 6 g. of hydrogen chloride gas are reacted together in the manner of Example I. A yield of 20 g. (95% of theory) of the title compound is obtained. 
     EXAMPLE IV 
     Preparation of N-(3-trifluoromethyl)-phenyl-N&#39;-methyl-N&#39;-ethylthiomethyl urea 
     Five grams (0.0353 mole) of the product of Example III, 6.55 g., (0.0353 mole) of 3-trifluoromethyl phenyl isocyanate; 3.57 g., (0.0353 mole) of triethylamine are reacted together in the manner of Example II. A yield of 9.2 g. (90% of theory) of the title compound is obtained, N D   30  - 1.4846. Structure is confirmed by IR and NMR. 
     EXAMPLE V 
     Preparation of N-methyl-N-(isopropylmercaptomethyl)-N&#39;-(3-trifluoromethylphenyl urea 
     Three grams of the product of Example III (0.02 mole) 3.7 g. (0.02 mole) of 3-trifluoromethylphenylisocyanate, and 25 ml. of acetonitrile are combined in a 125 ml. Erlenmeyer flask. The mixture is magnetically stirred, and 2.0 g. (0.02 mole) of triethylamine are then added. The resulting mixture is stirred at room temperature for one hour and then poured into 300 ml. of ice water. The crystalline product is collected by filtration and dried to yield 5 g. (82.78% of theory) of the title compound, mp = 76°-78° C. Structure is confirmed by IR and NMR. 
     EXAMPLE VI 
     Preparation of N-methyl-N-isopropylthiomethylamine hydrochloride 
     300 ml. of acetonitrile, 12.9 g. (0.1 mole) of 1,3,5-trimethylhexahydro-s-triazine, 22.8 g. (0.3 mole) of isopropyl mercaptan and 12 g. of hydrogen chloride gas are reacted together in the manner of Example I. A yield of 24.7 g. (52.95% of theory) of the title compound is obtained. 
     EXAMPLE VII 
     Preparation of N-methyl-N-tert.-octylthiomethylamine hydrochloride 
     300 ml. of acetonitrile, 12.9 g. (0.1 mole) of 1,3,5-trimethylhexahydro-s-triazine; 43.8 g. (0.3 mole) of tert.-octylthiomethylamine and 12 g. of hydrogen chloride gas are reacted together in the manner of Example I. A yield of 43.7 g. (64.6% of theory) of the title compound is obtained. 
     EXAMPLE VIII 
     Preparation of N-Methyl-N-(tert. octylthiomethyl)-N&#39;-(3-trifluoromethylphenyl) urea 
     Five grams of the product of Example III (0.02 mole), 4.15 g. (0.02 mole) of 3-trifluoromethylphenylisocyanate, and 100 ml. of acetonitrile are combined in a 250 ml. Erlenmeyer flask. The mixture is magnetically stirred, and 2.24 g. (0.02 mole) of triethylamine are then added. The resulting mixture is stirred at room temperature for 1 hour and then poured into 300 ml. of ice water. The crystalline product is collected by filtration and dried to yield 5 g. (59.9% of theory) of the title compound, mp = 52°-54° C. Structure is confirmed by IR and TLC. 
     
                       TABLE I______________________________________ ##STR13##Compound                         PhysicalNumber  R                X       Properties______________________________________ 1      C.sub.2 H.sub.5  Cl      N.sub.D.sup.30 -1.5387 2      (CH.sub.3).sub.2 CH                    H       mp. 76 - 78° C 3      (CH.sub.3).sub.3 C                    H       mp. 96 - 99° C 4      (CH.sub.3).sub.3 CCH.sub.2 (CH.sub.3).sub.2 C                    H       N.sub.D.sup.30 -1.4760 5      CH.sub.3 (CH.sub.2).sub.6 CH.sub.2                    H       N.sub.D.sup.30 -1.4712 6    ##STR14##       H 7      (C.sub.2 H.sub.5).sub.2 NCH.sub.2 CH.sub.2                    H       N.sub.D.sup.30 -1.4760 8    ##STR15##       H       N.sub.D .sup.30 -1.4820 9      C.sub.2 H.sub.5  H       N.sub.D.sup.30 -1.484610    ##STR16##       H       N.sub.D.sup.30 -1.484311      n-C.sub.3 H.sub.7                    H       mp. 60 - 64° C12      i-C.sub.3 H.sub.7                    Cl      N.sub.D.sup.30 -1.475213      (CH.sub.3).sub.3 C                    Cl      N.sub.D.sup.30 -1.488314      C.sub.8 H.sub.17 Cl      N.sub.D.sup.30 -1.471815      (CH.sub.3).sub.3 CCH.sub.2 (CH.sub.3).sub.2 C                    Cl      N.sub.D.sup.30 -1.484816    ##STR17##       Cl      N.sub.D.sup.30 -1.487817      CH.sub.3         H       N.sub.D.sup.30 -1.476018      n-C.sub.3 H.sub.7                    Cl      N.sub.D.sup.30 -1.497019    ##STR18##       Cl      N.sub.D.sup.30 -1.491420    ##STR19##       H       N.sub.D.sup.30 -1.475021      CH.sub.3         Cl      N.sub.D.sup.30 -1.503022      (CH.sub.3).sub.2 CHCH.sub.2 CH.sub.2                    H       N.sub.D.sup.30 -1.474323      (CH.sub.3).sub.2 CHCH.sub.2 CH.sub.2                    Cl      N.sub.D.sup.30 -1.488524      CH.sub.3 (CH.sub.2).sub.10 CH.sub.2                    H       mp. 34 - 37° C25      CH.sub.3 (CH.sub.2).sub.10 CH.sub.2                    Cl      N.sub.D.sup.30 -1.4780______________________________________ 
    
     As indicated, the compositions of the invention are phytotoxic compounds which are useful in controlling various plant species. Several of the compounds of the invention were tested as herbicides in the following manner. 
     A. Pre-emergence Screening Test: A fiber flat which is 7 inches long, 5 inches wide and 2.5 inches deep is filled to a depth of 2 inches with loamy sand soil. Seeds of seven different weed species are planted in individual rows, using one species per row across the width of the flat. The seeds are covered with soil so that they are planted at a depth of 0.5 inch. The seeds used are hairy crabgrass (Digitaria sanguinalis), foxtail (Setaria spp.), watergrass (Echinochloa crusgalli), red oat (avena sativa), redroot pigweed (Amaranthus retroflexus), mustard (Brassica juncea) and curly dock (Rumex crispus). Ample seeds are planted to give about 20 to 50 seedlings per row after emergence depending on the size of the plants. 
     The next day, about 20 mg. of the compound to be tested are weighed and placed in a 300 ml. wide-mouth bottle. About 3 ml. of acetone containing 1% Tween 20 R  is added to dissolve the compound. If the material is not soluble in acetone, another solvent such as water, alcohol or dimethylformamide (DMF) is used. When DMF is used, only 0.5 ml. or less is used to dissolve the compound and then another solvent is used to make the volume up to 3 ml. The 3 ml. of solution are sprayed uniformly on the soil contained in the Fiber Flat. A No. 152 DeVilbiss atomizer, which used compressed air at a pressure of 5 lb/sq. in. is used to apply the spray. The rate of application is 8 lb/acre and the spray volume is 143 gal/acre. This procedure is followed with each of the compounds tested. 
     After treatment the flats are placed in the greenhouse at a temperature of 70° to 85° F. and watered by sprinkling. Two and one-half weeks after treatment the degree of injury or control is determined by comparison with untreated check plants of the same age. The injury rating from 0 to 100% is recorded for each species as percent control with 0% representing no injury and 100% representing complete kill. The results of the test are shown in Table II. 
     
                       TABLE II______________________________________  Weed SpeciesCompound Crab-   Fox-   Water-                         Red  Pig- Mus- CurlyNumber   grass   tail   grass Oat  weed tard Dock______________________________________1        100     98     70    60   98   100  802        98      100    100   98   100  100  1003        100     100    100   90   100  90   904        90      90     95    80   90   100  985        95      95     100   90   100  100  986        100     100    100   100  100  100  1007        30      0      20    10   0    50   08        80      80     70    60   70   80   809        80      90     100   70   80   90   9010       60      70     80    50   50   100  6011       90      95     100   80   70   80   7012       70      60     50    40   90   100  8013       20      0      20    20   80   100  8014       0       0      0     0    40   20   2015       10      50     40    70   80   100  8016       0       0      10    20   0    50   017       20      0      50    40   80   90   2018       20      20     20    40   100  100  7019       0       0      0     0    0    60   020       50      50     70    70   0    100  7021       90      100    80    80   100  100  10022       100     100    100   60   80   100  10023       70      80     40    0    80   100  10024       60      60     20    20   0    70   60______________________________________ 
    
     B. Postemergence Herbicide Screening Test: Seeds of six plant species, including hairy crabgrass, watergrass, red oat, mustard, curly dock and Pinto beans (Phaseolus vulgaris) are planted in the fiber flats as described above for preemergence screening. The flats are placed in the greenhouse at 70 to 85° F. and watered daily with a sprinkler. About 8 to 12 days after planting, when the primary leaves of the bean plants are almost fully expanded and the first trifoliate leaves are just starting to form, the plants are sprayed. The spray is prepared by weighing out 20 mg. of the test compound, dissolving it in 5 ml. of acetone containing 1% Tween 20, and then adding 5 ml. of water. The solution is sprayed on the foliage using a No. 152 DeVilbiss atomizer at an air pressure of 5 lb/sq. in. The spray concentration is 0.2 and the rate is 8 lb/acre. The spray volume is 476 gal/acre. Results of the tests are shown in Table III. 
     
                       TABLE III______________________________________  Plant SpeciesCompound Crab-   Water   Red         Curly PintoNumber   grass   grass   Oat  Mustard                                Dock  Beans______________________________________1         99      99     100  100     99   1002        100     100      95  100    100   1003        100     100     100  100    100   1004        100     100     100  100    100   1005        100     100     100  100    100   1006        100     100     100  100    100   1007        100     100     100  100    100    808        100     100     100  100    100   1009        100     100     100  100    100   10010       100     100     100  100    100   10011       100     100     100  100    100   10012        98     100     100  100    100   10013       100     100     100  100    100   10014       100     100     100  100    100   10015        98     100     100  100    100   10016       100     100     100  100    100   10017       100     100     100  100    100   10018       100     100     100  100    100   10019       100     100     100  100    100   10020        98     100     100  100    100   10021       100     100     100  100    100   10022       100     100     100  100    100   10023       100     100     100  100    100   10024       100     100     100  100    100   10025       100     100      70  100    100   100______________________________________ 
    
     As can be seen by the test results, the compounds of the invention are useful as herbicides. Moreover, the compounds of this invention have high tolerance to valuable crops such as cotton. They may be applied directly to the particular undesired plant species or may be applied to a locus to be protected. In either event, it is, of course, necessary that the unwanted species receive an effective dosage of amount, i.e., an amount sufficient to kill or retard growth. 
     The compounds are normally employed with a suitable carrier and may be applied as a dust, spray, drench or aerosol. The compounds thus may be applied in combination with solvents, diluents, various surfact active agents (for example, detergents, soaps or other emulsifying or wetting agents, surface active clays), carrier media, adhesives, spreading agents, humectants and the like. They may also be combined with other biologically active compositions, including other herbicides, fungicides, bactericides and algaecides, insecticides, growth stimulators, acaricides, molluscicides, etc., as well as with fertilizers, soil modifiers, etc. The compounds of the invention may be used in combination with an inert carrier and a surface active or emulsifying agent and may also be applied in combination with other biologically active materials, in conjunction with a carrier and a surface active or emulsifying agent. The solid and liquid formulations can be prepared by any of the conventional methods well known by those skilled in the art. Determination of the optimum effective concentration for a specific application is readily conducted by routine procedures, as will be apparent to those skilled in the art. As indicated, the amount applied in a given case will be an effective amount, i.e., an amount sufficient to give the type of control desired. 
     Various changes and modifications may be made without departing from the spirit and the scope of the invention described herein, as will be apparent to those skilled in the art to which it pertains.