Herbicides

Abstract

The present invention relates to herbicidally active pyridino-/pyrimidino-pyridine derivatives. The invention further provides processes and intermediates used for the preparation of such derivatives. The invention further extends to herbicidal compositions comprising such derivatives, as well as to the use of such compounds and compositions in controlling undesirable plant growth: in particular the use in controlling weeds, in crops of useful plants.

1 . A method of controlling weeds at a locus, said method comprising applying to the locus a weed-controlling amount of a compound of formula (I) 
       
         
           
           
               
               
           
         
         or a salt or N-oxide thereof, wherein, 
         X 1  is N or CR 1 ; 
         R 1  is selected from the group consisting of hydrogen, halogen, cyano, C 1 -C 6 alkyl, C 3 -C 6 cycloalkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 1 -C 6 alkoxy, —C(O)OC 1 -C 6 alkyl, —S(O) p C 1 -C 6 alkyl, NR 6 R 7 , C 1 -C 6 haloalkoxy and C 1 -C 6 haloalkyl; 
         R 2  is selected from the group consisting of halogen, cyano, nitro, C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 3 -C 6 cycloalkyl, —C(O)OC 1 -C 6 alkyl, —S(O) p (C 1 -C 6 alkyl), C 1 -C 6 alkoxy and C 1 -C 6 haloalkoxy; 
         R 3  is —C(O)R 9 ; 
         R 4  is selected from the group consisting of hydrogen, C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, C 3 -C 6 alkenyl, C 3 -C 6 alkynyl, C r alkoxyC s alkyl, -C r alkoxyC s haloalkyl, C r alkoxyC s thioalkyl, —C(O)R 9  and —(CR a R b ) q R 5 ; 
         each R a  is independently hydrogen or C 1 -C 2  alkyl; 
         each R b  is independently hydrogen or C 1 -C 2  alkyl; 
         R c  is hydrogen or C 1 -C 4 alkyl; 
         R 5  is —C(O)OC 1 -C 6 alkyl, —C 3 -C 6 cycloalkyl, cyano, —NR 6 R 7 , —C(O)NR a R b , —S(O) p (R 11 ) n , -aryl or -heteroaryl wherein said aryl and heteroaryl are optionally substituted by 1 to 3 independent R 8 ; 
         R 6  and R 7  are independently selected from the group consisting of hydrogen and C 1 -C 6 alkyl; 
         each R 8  is independently selected from the group consisting of halogen, C 1 -C 6  alkyl and C 1 -C 6 alkoxy-, C 1 -C 6  haloalkyl, C 1 -C 6  haloalkoxy-, cyano and S(O) p (C 1 -C 6 alkyl); 
         each R 9  is independently selected from the group consisting of hydrogen, C 1 -C 6 alkyl, C r alkoxyC s alkyl, C 1 -C 6 haloalkyl, C r alkoxyC s haloalkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, and —(CR a R b ) q R 10 ; 
         or R 4  and R 9  together with the atoms to which they are joined form a 5-7 membered ring system containing from 1 to 3 heteroatoms, wherein at least one heteroatom is N, and any additional heteroatom is independently selected from S, O and N; 
         R 10  is —C(O)OR c , —OC(O)R c , —C 3 -C 6 cycloalkyl, or an -aryl, -aryloxy, -heteroaryl, -heteroaryloxy or -heterocyclyl ring, wherein said ring is optionally substituted by 1 to 3 independent R 8 ; 
         each n is independently 0 or 1; 
         p is 0, 1, or 2; 
         each q is independently 0, 1,2, 3, 4, 5 or 6; 
         r is 1,2, 3, 4, or 5; 
         s is 1,2, 3, 4, or 5, and the sum of r+s is less than or equal to 6; and, 
         R 11  is C 1 -C 6 alkyl. 
       
     
     
         2 . The method of  claim 1 , wherein X 1  is N. 
     
     
         3 . The method of  claim 1 , wherein X 1  is CR 1  and R 1  is halogen or cyano. 
     
     
         4 . The method of  claim 1 , wherein R 2  is halogen, cyano, C 1 -C 6 alkyl or C 1 -C 6 haloalkyl. 
     
     
         5 . The method of  claim 1 , wherein R 3  is —C(O)C 1 -C 6 alkyl, —C(O)C 1 -C 3 haloalkyl, —C(O)C 1 -C 3 alkoxyC 1 -C 3 alkyl or —C(O)(CR a R b ) q R 10 . 
     
     
         6 . The method of  claim 5 , wherein R 10  is —C(O)OR c , —OC(O)R c , cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, or a ring system selected from phenyl, phenoxy, pyridinyl, pyrimidinyl, thiazolyl, and thiophenyl, wherein said ring system is optionally substituted by 1-3 independent R 8 . 
     
     
         7 . The method of  claim 1 , wherein R 4  is selected from the group consisting of hydrogen, C 1 -C 4 alkyl, C 3 -C 6 alkenyl, C r alkoxyC s alkyl, C r alkylthioC s alkyl, C 3 -C 6 alkynyl, C 1 -C 3 haloalkyl, C r alkoxyC s haloalkyl, —C(O)R 9 , and —(CR a R b ) q R 5 . 
     
     
         8 . The method of  claim 7 , wherein R 4  is —C(O)C 1 -C 3 alkyl, —C(O)C 2 -C 4 alkenyl, or —C(O)(CR a R b ) q R 10 . 
     
     
         9 . The method of  claim 7 , wherein R 4  is —(CR a R b ) q R 5 , wherein
 q is 1,2, or 3; 
 R a  and R b  are independently hydrogen, methyl or ethyl; and, 
 R 5  is —C(O)NR a R b , —NR 6 R 7 , cyano, —C 3 -C 6 cycloalkyl, -aryl or -heteroaryl, wherein said aryl and heteroaryl are optionally substituted by 1 to 3 independent R 8 . 
 
     
     
         10 . The method of  claim 1 , wherein said weeds are of a genus selected from the group consisting of  Brachiaria, Cenchrus, Digitaria, Echinochloa, Eleusine, Eriochloa, Panicum, Setaria, Sorghum , and volunteer  Zea mays.    
     
     
         11 . The method of  claim 1 , wherein the weed-controlling amount of the compound of formula (I) is applied to said locus at a rate of between 50 g/Ha and 1000 g/Ha. 
     
     
         12 . The method of  claim 1  wherein the weed controlling amount of a compound of formula (I) is applied to said locus in combination with a further herbicide. 
     
     
         13 . A herbicidal composition comprising from 0.1 to 99% by weight of an active ingredient and from 1 to 99.9% by weight of a formulation adjuvant, wherein said active ingredient consists of either (i) a compound of formula (I), 
       
         
           
           
               
               
           
         
         or a salt or N-oxide thereof, wherein, 
         X 1  is N or CR 1 ; 
         R 1  is selected from the group consisting of hydrogen, halogen, cyano, C 1 -C 6 alkyl, C 3 -C 6 cycloalkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 1 -C 6 alkoxy, —C(O)OC 1 -C 6 alkyl, —S(O) p C 1 -C 6 alkyl, NR 6 R 7 , C 1 -C 6 haloalkoxy and C 1 -C 6 haloalkyl; 
         R 2  is selected from the group consisting of halogen, cyano, nitro, C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 3 -C 6 cycloalkyl, —C(O)OC 1 -C 6 alkyl, —S(O) p (C 1 -C 6 alkyl), C 1 -C 6 alkoxy and C 1 -C 6 haloalkoxy; 
         R 3  is —C(O)R 9 ; 
         R 4  is selected from the group consisting of hydrogen, C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, C 3 -C 6 alkenyl, C 3 -C 6 alkynyl, C r alkoxyC s alkyl, —C r alkoxyC s haloalkyl, C r alkoxyC s thioalkyl, —C(O)R 9  and —(CR a R b ) q R 5 ; 
         each R a  is independently hydrogen or C 1 -C 2  alkyl; 
         each R b  is independently hydrogen or C 1 -C 2  alkyl; 
         R c  is hydrogen or C 1 -C 4 alkyl; 
         R 5  is —C(O)OC 1 -C 6 alkyl, —C 3 -C 6 cycloalkyl, cyano, —NR 6 R 7 , —C(O)NR a R b , —S(O) p (R 11 ) n , -aryl or -heteroaryl wherein said aryl and heteroaryl are optionally substituted by 1 to 3 independent R 8 ; 
         R 6  and R 7  are independently selected from the group consisting of hydrogen and C 1 -C 6 alkyl; 
         each R 8  is independently selected from the group consisting of halogen, C 1 -C 6  alkyl and C 1 -C 6 alkoxy-, C 1 -C 6  haloalkyl, C 1 -C 6  haloalkoxy-, cyano and S(O) p (C 1 -C 6 alkyl); 
         each R 9  is independently selected from the group consisting of hydrogen, C 1 -C 6 alkyl, C r alkoxyC s alkyl, C 1 -C 6 haloalkyl, C r alkoxyC s haloalkyl, C 2 -C 6 alkenyl, C 2 -C s alkynyl, and —(CR a R b ) q R 10 ; 
         or R 4  and R 9  together with the atoms to which they are joined form a 5-7 membered ring system containing from 1 to 3 heteroatoms, wherein at least one heteroatom is N, and any additional heteroatom is independently selected from S, O and N; 
         R 10  is —C(O)OR c , —OC(O)R c , —C 3 -C 6 cycloalkyl, or an -aryl, -aryloxy, -heteroaryl, -heteroaryloxy or -heterocyclyl ring, wherein said ring is optionally substituted by 1 to 3 independent R 8 ; 
         each n is independently 0 or 1; 
         p is 0, 1, or 2; 
         each q is independently 0,1,2, 3, 4, 5 or 6; 
         r is 1,2, 3, 4, or 5; 
         s is 1,2, 3, 4, or 5, and the sum of r+s is less than or equal to 6; and, 
         R 11  is C 1 -C 6 alkyl, 
         or (ii) a compound of formula (I) as defined in (i) and a further herbicide, 
         or (iii) a compound of formula (I) as defined in (i) and a safener, 
         and wherein the formulation adjuvant includes from 0 to 25% by weight of a surface-active substance. 
       
     
     
         14 . The herbicidal composition of  claim 13 , wherein the surface active agent is a cationic, anionic, amphoteric or non-ionic type surface active agent. 
     
     
         15 . The herbicidal composition of  claim 13 , wherein the further herbicide is selected from the group consisting of 
     
     
         16 . The herbicidal composition of  claim 13 , wherein the safener is selected from the group consisting of 
     
     
         17 . The method of  claim 1 , wherein the compound of formula (I) is in the form of the composition of  claim 13 .