Herbicidal 5-pyrimidinecarbonitriles

Abstract

5-Pyrimidinecarbonitriles, having amino substituents in the 2 and 6 positions and an alkoxy substituent in the 4 position, exhibit herbicidal activity. The preparation of novel active compounds and intermediates in this class is described; herbicidal compositions containing the active compounds are illustrated; and methods for utilizing the herbicidal compositions to control plant growth are disclosed.

I claim: .[.1. A chemical compound having the structural formula ##STR3## wherein 
     
        amino..]. .[.2.  A chemical compound of claim 1 wherein the halogen is 
     
     
        chlorine..]. 3. A chemical compound having the structural formula ##STR4## wherein (a) R 2  is a radical selected from amino, lower alkylamino, lower cycloalkylamino, di(lower alkyl)amino, and [alpha-cyano(lower alkyl)]amino; (b) R 4  is a lower alkoxy radical; and   (c) R 6  is a radical selected from amino, lower alkylamino, lower cycloalkylamino, and di(lower alkyl)amino; with the proviso that neither R 2  nor R 6  is tert-butylamino; and provided further that when R 2  is isopropylamino, R 6  is other than n-butylamino; and when R 2  is methylethylamino, R 6  is other than isopropylamino; and when R 2  is diethylamino, R 6  is other     
     
     
        than amino. 4. A chemical compound of claim 3 wherein R 2  is selected from lower alkylamino (except tert-butylamino) and [alpha-cyano-(lower alkyl)]amino; and R 6  is selected from lower alkylamino (except 
     
     
        tert-butylamino) and lower cycloalkylamino. 5. A chemical compound of claim 4 wherein R 2  is selected from ethylamino, isopropylamino, 1-methylpropylamino, 2-methylpropylamino, and 1-cyano-1-methylethylamino; R 4  is methoxy or ethoxy; and R 6  is selected from ethylamino, 
     
     
        isopropylamino and cyclopropylamino. 6. The chemical compound of claim 5 which is 2-(1-cyano-1-methylethylamino)-6-ethylamino-4-methoxy-5-pyrimidinecarbonit 
     
     
       rile. 7. The chemical compound of claim 5 which is 2-(1-cyano-1-methylethylamino)-6-cyclopropyl-amino-4-methoxy-5-pyrimidinec 
     
     
       arbonitrile. 8. The chemical compound of claim 5 which is 2-(1-cyano-1-methylethylamino)-6-isopropylamino-4-methoxy-5-pyrimidinecarb 
     
     
       onitrile. 9. An herbicidal composition comprising an herbicidally effective amount of at least one of the chemical compounds of claim 3 in admixture 
     
     
        with an agriculturally acceptable carrier and a surfactant. 10. An herbicidal composition of claim 9 wherein R 2  is selected from lower alkylamino (except tert-butylamino) and [alpha-cyano(lower alkyl)]amino; and R 6  is selected from lower alkylamino (except tert-butylamino) and 
     
     
        lower cycloalkylamino. 11. An herbicidal composition of claim 10 wherein R 2  is selected from ethylamino, isopropylamino, 1-methylpropylamino, 2-methylpropylamino, and 1-cyano-1-methylethylamino; R 4  is methoxy or ethoxy; and R 6  is selected from ethylamino, isopropylamino and 
     
     
        cyclopropylamino. 12. An herbicidal composition of claim 11 in which the chemical compound is 2-(1-cyano-1-methylethylamino)-6-ethylamino-4-methoxy-5-pyrimidinecarbonit 
     
     
       rile. 13. An herbicidal composition of claim 11 in which the chemical compound is 2-(1-cyano-1-methylethylamino)-6-cyclopropylamino-4-methoxy-5-pyrimidineca 
     
     
       rbonitrile. 14. An herbicidal composition of claim 11 in which the chemical compound is 2-(1-cyano-1-methylethylamino)-6-isopropylamino-4-methoxy-5-pyrimidinecarb 
     
     
       ontrile. 15. A method of controlling plant growth which comprises applying to the locus of the plants an herbicidally effective amount of a chemical 
     
     
        compound of claim 3. 16. A method of claim 15 wherein the chemical compound is selected from 2-(1-cyano-1-methylethylamino)-6-isopropylamino-4-methoxy-5-pyrimidinecarbonitrile, 2-(1-cyano-1-methylethylamino)-6-ethylamino-4-methoxy-5-pyrimidinecarbonitrile, and 2-(1-cyano-1-methylethylamino)-6-cyclopropylamino-4-methoxy-5-pyrimidineca 
     
     
       rbonitrile. 17. A method of claim 16 wherein the growth of weeds is controlled without substantially affecting Zea mays in the same locus. 
     
     
            A method of claim 16 wherein the growth of weeds is controlled without 
     
     
        substantially affecting Gossypium hirsutum in the same locus. 19. The method of claim 18 wherein the chemical compound is 2-(1-cyano-1-methylethylamino)-6-isopropylamino-4-methoxy-5-pyrimidinecarb 
     
     
       onitrile. 20. A method of claim 16 wherein the growth of weeds is controlled without substantially affecting Sorghum vulgare in the same 
     
     
        locus. 21. A method of claim 16 wherein the growth of weeds is controlled 
     
     
        without substantially affecting Glycine max in the same locus. 22. A method of claim 16 wherein the growth of weeds is controlled without substantially affecting Arachis hypogaea in the same locus.