Fungicidal pyridazinones

1 . A compound selected from Formula 1, N-oxides and salts thereof,

wherein

W is C(═O) or C(═S);

R 1 is H, C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, C 2 -C 6 alkenyl, C 2 -C 6 haloalkenyl, C 2 -C 6 alkynyl, C 2 -C 6 haloalkynyl, C 3 -C 6 cycloalkyl, C 3 -C 6 halocycloalkyl, C 4 -C 7 cycloalkylalkyl, C 4 -C 7 alkylcycloalkyl, C 2 -C 6 cyanoalkyl, C 1 -C 6 alkoxy, C 1 -C 6 haloalkoxy, C 2 -C 6 alkoxyalkyl, C 2 -C 6 haloalkoxyalkyl, C 3 -C 6 alkoxyalkoxyalkyl, C 1 -C 6 alkylthio, C 1 -C 6 haloalkylthio, C 2 -C 4 alkylthioalkyl, C 1 -C 6 alkylsulfinyl, C 1 -C 6 haloalkylsulfinyl, C 2 -C 6 alkylsulfinylalkyl, C 1 -C 6 alkylsulfonyl, C 1 -C 6 haloalkylsulfonyl, C 2 -C 6 alkylsulfonylalkyl, C 1 -C 6 alkylsulfonyloxy, C 1 -C 6 alkylaminosulfinyl, C 1 -C 6 haloalkylaminosulfinyl, C 2 -C 6 dialkylaminosulfinyl, C 1 -C 6 alkylaminosulfonyl, C 1 -C 6 haloalkylaminosulfonyl, C 2 -C 6 dialkylaminosulfonyl, C 2 -C 6 alkylcarbonyl, C 2 -C 6 haloalkylcarbonyl, C 2 -C 6 alkoxycarbonyl, C 3 -C 6 alkylcarbonylalkyl, C 3 -C 6 alkoxycarbonylalkyl, C 2 -C 6 alkylaminocarbonyl, C 2 -C 6 haloalkylaminocarbonyl, C 3 -C 6 dialkylaminocarbonyl or -L(CR 5a R 5b ) m Q 1 ;

L is O or a direct bond;

each R 5a is independently H, cyano, halogen or C 1 -C 4 alkyl;

each R 5b is independently H or C 1 -C 4 alkyl;

Q 1 is a phenyl ring optionally substituted with up to 5 substituents independently selected from R 6a ; or a 5- to 6-membered heterocyclic ring, each ring containing ring members selected from carbon atoms and 1 to 4 heteroatoms independently selected from up to 2 O, up to 2 S and up to 4 N atoms, wherein up to 2 ring members are independently selected from C(═O), C(═S), S(═O) and S(═O) 2 , each ring optionally substituted with up to 5 substituents independently selected from R 6a on carbon atom ring members and R 6b on nitrogen atom ring members;

each R 6a is independently halogen, cyano, hydroxy, nitro, amino, C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, C 2 -C 6 alkenyl, C 2 -C 6 haloalkenyl, C 2 -C 6 alkynyl, C 2 -C 6 haloalkynyl, C 3 -C 6 cycloalkyl, C 3 -C 6 halocycloalkyl, C 4 -C 6 alkylcycloalkyl, C 4 -C 6 cycloalkylalkyl, C 2 -C 6 cyanoalkyl, C 1 -C 6 alkoxy, C 1 -C 6 haloalkoxy, C 3 -C 6 cycloalkoxy, C 2 -C 6 alkylcarbonyloxy, C 2 -C 6 alkylcarbonyl, C 2 -C 6 haloalkylcarbonyl, C 3 -C 6 alkylcarbonylalkyl, C 1 -C 6 alkylthio, C 1 -C 6 haloalkylthio, C 1 -C 6 alkylsulfinyl, C 1 -C 6 haloalkylsulfinyl, C 1 -C 6 alkylsulfonyl, C 1 -C 6 haloalkylsulfonyl, C 1 -C 6 alkylsulfonyloxy, C 1 -C 6 haloalkylsulfonyloxy, C 1 -C 6 alkylamino, C 2 -C 6 dialkylamino, C 2 -C 6 alkylcarbonylamino, CH(═O), —NHCH(═O), —SF 5 , —SC≡N or —U—V-T;

G is C(═O), C(═S), S(═O), S(═O) 2 ; or C(═N)-J;

J is NR A R B or —ORS;

R A is H, cyano, CHO, C 2 -C 4 alkylcarbonyl, C 1 -C 4 alkyl; or phenyl substituted or unsubstituted with halogen or C 1 -C 4 alkyl;

R B is H, cyano, CHO, C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, C 2 -C 6 alkenyl, C 3 -C 6 alkynyl, C 2 -C 8 alkoxyalkyl, C 2 -C 8 haloalkoxyalkyl, C 2 -C 8 alkylthioalkyl, C 2 -C 8 alkylsulfinylalkyl, C 2 -C 8 alkylsulfonylalkyl, C 2 -C 8 alkylcarbonyl, C 2 -C 8 haloalkylcarbonyl, C 4 -C 10 cycloalkylcarbonyl, C 2 -C 8 alkoxycarbonyl, C 2 -C 8 haloalkoxycarbonyl, C 4 -C 10 cycloalkoxycarbonyl, C 2 -C 8 alkylaminocarbonyl, C 3 -C 10 dialkylaminocarbonyl, C 4 -C 10 cycloalkylaminocarbonyl, C 1 -C 6 alkoxy, C 1 -C 6 alkylthio, C 1 -C 6 haloalkylthio, C 3 -C 8 cycloalkylthio, C 1 -C 6 alkylsulfinyl, C 1 -C 6 haloalkylsulfinyl, C 3 -C 8 cycloalkylsulfinyl, C 1 -C 6 alkylsulfonyl, C 1 -C 6 haloalkylsulfonyl, C 3 -C 8 cycloalkylsulfonyl, C 1 -C 6 alkylaminosulfonyl, C 2 -C 8 dialkylaminosulfonyl or C 3 -C 10 trialkylsilyl; or a phenyl ring or a naphthalenyl ring system, each ring or ring system substituted or unsubstituted with up to 5 substituents independently selected from R 16 ; or a 4- to 7-membered heterocyclic ring, substituted or unsubstituted on ring members with up to 5 substituents independently selected from R 16 ; or

R A and R B are taken together along with the nitrogen atom to which they are both bonded to form a 4-, 5- or 6-membered ring containing ring members selected from carbon, oxygen, nitrogen and C(═O); or taken together as a 6- to 10-membered bicyclic ring system; or taken together as an 8- to 13-membered tricyclic ring system, each ring or ring system containing ring members selected from carbon, nitrogen and C(═O) and substituted or unsubstituted with halogen, cyano or C 1 -C 4 alkyl;

R C is H, CHO, C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, C 2 -C 6 alkenyl, C 3 -C 6 alkynyl, C 2 -C 8 alkoxyalkyl, C 2 -C 8 haloalkoxyalkyl, C 2 -C 8 alkylthioalkyl, C 2 -C 8 alkylsulfinylalkyl, C 2 -C 8 alkylsulfonylalkyl, C 2 -C 8 alkylcarbonyl, C 2 -C 8 haloalkylcarbonyl, C 4 -C 10 cycloalkylcarbonyl, C 2 -C 8 alkoxycarbonyl, C 2 -C 8 haloalkoxycarbonyl, C 4 -C 10 cycloalkoxycarbonyl, C 2 -C 8 alkylaminocarbonyl, C 3 -C 10 dialkylaminocarbonyl, C 4 -C 10 cycloalkylaminocarbonyl, C 1 -C 6 alkoxy, C 1 -C 6 alkylthio, C 1 -C 6 haloalkylthio, C 3 -C 8 cycloalkylthio, C 1 -C 6 alkylsulfinyl, C 1 -C 6 haloalkylsulfinyl, C 3 -C 8 cycloalkylsulfinyl, C 1 -C 6 alkylsulfonyl, C 1 -C 6 haloalkylsulfonyl, C 3 -C 8 cycloalkylsulfonyl, C 1 -C 6 alkylaminosulfonyl, C 2 -C 8 dialkylaminosulfonyl or C 3 -C 10 trialkylsilyl; or a phenyl ring or a naphthalenyl ring system, each ring or ring system substituted or unsubstituted with up to 5 substituents independently selected from R 16 ; or a 4- to 7-membered heterocyclic ring, substituted or unsubstituted on ring members with up to 5 substituents independently selected from R 16 ;

A is N(R 7a ), N(R 7b )S(═O) n or S(═O) n N(R 7b );

R 2 is —(CR 31a R 31b ) r Q 2 ;

each R 31a is independently H, cyano, halogen or C 1 -C 4 alkyl;

each R 31b is independently H or C 1 -C 4 alkyl;

Q 2 is a phenyl ring or a naphthalenyl ring system, each ring or ring system optionally substituted with up to 5 substituents independently selected from R 8a ; or a 5- to 6-membered heterocyclic ring, each ring containing ring members selected from carbon atoms and 1 to 4 heteroatoms independently selected from up to 2 O, up to 2 S and up to 4 N atoms, wherein up to 2 carbon ring members are independently selected from C(═O), C(═S), S(═O) and S(═O) 2 , each ring optionally substituted with up to 5 substituents independently selected from R 8a on carbon atom ring members and R 8b on nitrogen atom ring members; or an 8- to 10-membered bicyclic ring system, each ring or ring system containing ring members selected from carbon atoms and 1 to 5 heteroatoms independently selected from up to 2 O, up to 2 S and up to 5 N atoms, wherein up to 3 carbon ring members are independently selected from C(═O) and C(═S), and the sulfur atom ring members are independently selected from S(═O) a (═NR 8c ) b , each ring or ring system optionally substituted with up to 5 substituents independently selected from R 8a on carbon atom ring members and selected from R 8b on nitrogen atom ring members;

R 3 is H, halogen, OR 9 , OC(═Z)R 10 , SH, SR 11 , S(═O) u R 11 , OS(═O) u R 11 , NR 32 R 33 , OC(═Z)NR 12 R 13 , S(═O) u NR 12 R 13 , OP(═O)(R 34 ) 2 , C 1 -C 4 alkyl, C 1 -C 4 haloalkyl, C 2 -C 4 alkenyl, C 2 -C 4 haloalkenyl, C 1 -C 4 alkoxy, C 2 -C 4 alkoxyalkyl, C 3 -C 6 cycloalkyl or C 4 -C 7 cycloalkylalkyl;

R 4 is H, halogen, cyano, hydroxy, nitro, amino, C 1 -C 3 alkyl, C 1 -C 3 haloalkyl, C 2 -C 4 alkenyl, C 2 -C 4 haloalkenyl, C 2 -C 4 alkynyl, C 2 -C 4 haloalkynyl, C 1 -C 3 alkoxy, C 1 -C 3 haloalkoxy, C 2 -C 4 alkoxyalkyl, C 1 -C 3 alkylthio, C 1 -C 3 haloalkylthio, C 1 -C 3 alkylsulfinyl, C 1 -C 3 haloalkylsulfinyl, C 2 -C 4 alkylsulfinylalkyl, C 1 -C 3 alkylsulfonyl, C 1 -C 3 haloalkylsulfonyl, C 2 -C 4 alkylsulfonylalkyl, C 2 -C 4 alkylcarbonyl, C 2 -C 4 haloalkylcarbonyl, C 2 -C 4 alkoxycarbonyl, C 3 -C 4 alkoxycarbonylalkyl, C 1 -C 6 alkylamino, C 2 -C 6 dialkylamino, C 2 -C 4 alkylaminocarbonyl or C 3 -C 4 dialkylaminocarbonyl; or a phenyl ring optionally substituted with up to 5 substituents independently selected from R 26 ;

each R 8a is independently halogen, cyano, hydroxy, nitro,

amino, —CH(═O), —C(═O)OH, —C(═O)NH 2 , —C(R 11a )═N—O—R 12a , —C(R 11a )═N_R 12a , C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, C 2 -C 6 alkenyl, C 2 -C 6 haloalkenyl, C 2 -C 6 alkynyl, C 2 -C 6 haloalkynyl, C 3 -C 6 cycloalkyl, C 3 -C 6 halocycloalkyl, C 4 -C 6 alkylcycloalkyl, C 4 -C 6 cycloalkylalkyl, C 2 -C 6 cyanoalkyl, C 1 -C 6 alkoxy, C 1 -C 6 haloalkoxy, C 3 -C 6 cycloalkoxy, C 2 -C 6 alkylcarbonyloxy, C 2 -C 6 alkylcarbonyl, C 2 -C 6 haloalkylcarbonyl, C 3 -C 6 alkylcarbonylalkyl, C 1 -C 6 alkylthio, C 1 -C 6 haloalkylthio, C 1 -C 6 alkylsulfinyl, C 1 -C 6 haloalkylsulfinyl, C 1 -C 6 alkylsulfonyl, C 1 -C 6 haloalkylsulfonyl, C 1 -C 6 alkylsulfonyloxy, C 1 -C 6 haloalkylsulfonyloxy, C 1 -C 6 alkylamino, C 2 -C 6 dialkylamino, C 2 -C 8 alkylaminocarbonyl, C 3 -C 10 dialkylaminocarbonyl, C 3 -C 10 dihaloalkylaminocarbonyl; C 4 -C 10 cycloalkylaminocarbonyl, C 2 -C 8 haloalkylcarbonylamino, C 2 -C 6 alkylcarbonylamino, —NHCH(═O), —SF 5 , —SC≡N or —U—V-T; or a phenyl or phenoxy ring optionally substituted with up to 5 substituents independently selected from R 27 ;

each R 6b and R 8b is independently cyano, C 1 -C 3 alkyl, C 2 -C 4 alkenyl, C 2 -C 4 alkynyl, C 3 -C 6 cycloalkyl, C 1 -C 3 alkoxy, C 2 -C 4 alkoxyalkyl, C 2 -C 4 alkylcarbonyl, C 2 -C 4 alkoxycarbonyl, C 2 -C 4 alkylaminoalkyl or C 3 -C 4 dialkylaminoalkyl,

R 7a and R 7b are each H, hydroxy, amino, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 3 -C 6 cycloalkyl, C(═O)H, S(═O) t R 14 , C(═Z)R 15 or OR 16 ; or C 1 -C 6 alkyl or C 1 -C 6 haloalkyl, each optionally substituted with up to 2 substituents independently selected from R 17 ;

each R 8c is independently H, cyano, C 2 -C 3 alkylcarbonyl or C 2 -C 3 haloalkylcarbonyl;

R 9 is H, CH(═O) or C 3 -C 6 cycloalkyl; or C 1 -C 6 alkyl, C 2 -C 6 alkenyl or C 1 -C 6 haloalkyl, each optionally substituted with up to 2 substituents independently selected from R 19 or a phenyl ring optionally substituted with up to 5 substituents independently selected from R 28 ; or

R 9 and R 7a are taken together to form a ring selected from the group consisting

R 10 is —C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, C 2 -C 6 alkenyl, C 2 -C 6 haloalkenyl, C 3 -C 6 cycloalkyl, C 1 -C 6 alkoxy, C 1 -C 6 haloalkoxy, C 2 -C 6 alkoxyalkyl, C 1 -C 6 alkylthio, C 1 -C 6 haloalkylthio, C 2 -C 6 alkylthioalkyl, C 2 -C 6 alkylaminoalkyl, C 3 -C 6 dialkylaminoalkyl; or a phenyl ring optionally substituted with up to 5 substituents independently selected from R 28 ;

R 11 is —C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, C 2 -C 6 alkenyl, C 2 -C 6 haloalkenyl, C 3 -C 6 cycloalkyl, C 1 -C 6 alkoxy, C 1 -C 6 haloalkoxy, C 2 -C 6 alkoxyalkyl, C 1 -C 6 alkylthio, C 1 -C 6 haloalkylthio, C 2 -C 6 alkylthioalkyl, C 2 -C 6 alkylaminoalkyl, C 3 -C 6 dialkylaminoalkyl; or phenyl or phenylmethyl, each optionally substituted on ring members with up to 5 substituents independently selected from R 29 ;

each R 11a is independently H, C 1 -C 3 alkyl, C 1 -C 3 haloalkyl or C 1 -C 3 cycloalkyl;

each R 12a is independently H, C 1 -C 3 alkyl, C 1 -C 3 haloalkyl, C 2 -C 3 alkylcarbonyl or C 2 -C 3 haloalkylcarbonyl;

R 12 and R 13 are each independently H, C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, C 2 -C 6 alkenyl, C 2 -C 6 haloalkenyl, C 3 -C 6 cycloalkyl, C 2 -C 6 alkylcarbonyl, C 2 -C 6 haloalkylcarbonyl, C 2 -C 6 alkoxycarbonyl or C 2 -C 6 haloalkoxycarbonyl;

R 14 is —C 1 -C 6 alkyl or C 1 -C 6 haloalkyl;

R 15 is C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, C 1 -C 6 alkoxy, C 1 -C 6 haloalkoxy, C 2 -C 6 alkoxyalkyl, C 1 -C 6 alkylthio, C 2 -C 6 alkylthioalkyl, C 2 -C 6 alkylaminoalkyl, C 3 -C 6 dialkylaminoalkyl; or a phenyl ring optionally substituted with up to 5 substituents independently selected from R 30 ;

R 16 is H, CH(═O), C 3 -C 6 cycloalkyl or (C═Z)R 20 ; or C 1 -C 6 alkyl or C 1 -C 6 haloalkyl, each optionally substituted with up to 2 substituents independently selected from R 18 ;

each R 17 , R 18 and R 19 is independently cyano, C 3 -C 6 cycloalkyl, C 1 -C 6 alkoxy, C 1 -C 6 haloalkoxy, C 1 -C 6 alkylthio, C 1 -C 6 alkylsulfinyl or C 1 -C 6 alkylsulfonyl;

R 20 are each independently C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, C 2 -C 6 alkenyl, C 2 -C 6 haloalkenyl, C 1 -C 6 alkoxy, C 1 -C 6 haloalkoxy, C 2 -C 6 alkoxyalkyl, C 1 -C 6 alkylthio, C 2 -C 6 alkylthioalkyl, C 2 -C 6 alkylaminoalkyl or C 3 -C 6 dialkylaminoalkyl,

each U is independently O, S(═O) s , N(R 21 ) or a direct bond;

each V is independently C 1 -C 6 alkylene, C 2 -C 6 alkenylene, C 3 -C 6 alkynylene, C 3 -C 6 cycloalkylene or C 3 -C 6 cycloalkenylene, wherein up to 3 carbon atoms are independently selected from C(═O), each optionally substituted with up to 5 substituents independently selected from halogen, cyano, nitro, hydroxy, C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, C 1 -C 6 alkoxy and C 1 -C 6 haloalkoxy;

each T is independently cyano, NR 22a R 22b , OR 23 or S(═O) s R 23 ;

each R 21 is independently H, C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, C 2 -C 6 alkylcarbonyl, C 2 -C 6 alkoxycarbonyl, C 2 -C 6 (alkylthio)carbonyl, C 2 -C 6 alkoxy(thiocarbonyl), C 4 -C 8 cycloalkylcarbonyl, C 4 -C 8 cycloalkoxycarbonyl, C 4 -C 8 (cycloalkylthio)carbonyl or C 4 -C 8 cycloalkoxy(thiocarbonyl);

each R 22a and R 22b is independently H, C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, C 2 -C 6 alkenyl, C 3 -C 6 alkynyl, C 3 -C 6 cycloalkyl, C 3 -C 6 halocycloalkyl, C 2 -C 6 alkylcarbonyl, C 2 -C 6 alkoxycarbonyl, C 2 -C 6 (alkylthio)carbonyl, C 2 -C 6 alkoxy(thiocarbonyl), C 4 -C 8 cycloalkylcarbonyl, C 4 -C 8 cycloalkoxycarbonyl, C 4 -C 8 (cycloalkylthio)carbonyl or C 4 -C 8 cycloalkoxy(thiocarbonyl); or

a pair of R 22a and R 22b are taken together with the nitrogen atom to which they are attached to form a form a 3- to 6-membered heterocyclic ring, the ring optionally substituted with up to 5 substituents independently selected from R 24 ;

each R 23 is independently H, C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, C 2 -C 6 alkenyl, C 3 -C 6 alkynyl, C 3 -C 6 cycloalkyl, C 3 -C 6 halocycloalkyl, C 2 -C 6 alkylcarbonyl, or C 2 -C 6 alkoxycarbonyl;

each R 24 is independently halogen, C 1 -C 6 alkyl, C 1 -C 6 haloalkyl or C 1 -C 6 alkoxy;

each R 25 is independently halogen, hydroxy, amino, cyano, nitro, C 1 -C 3 alkyl, C 1 -C 3 haloalkyl, C 1 -C 2 alkoxy or C 1 -C 2 haloalkoxy;

each R 26 , R 27 , R 28 , R 29 and R 30 is independently halogen, cyano, hydroxy, nitro, amino, C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, C 2 -C 6 alkenyl, C 2 -C 6 haloalkenyl, C 2 -C 6 alkynyl, C 2 -C 6 haloalkynyl, C 3 -C 6 cycloalkyl, C 3 -C 6 halocycloalkyl, C 4 -C 6 alkylcycloalkyl, C 4 -C 6 cycloalkylalkyl, C 2 -C 6 cyanoalkyl, C 1 -C 6 alkoxy, C 1 -C 6 haloalkoxy, C 3 -C 6 cycloalkoxy, C 2 -C 6 alkylcarbonyloxy, C 2 -C 6 alkylcarbonyl, C 2 -C 6 haloalkylcarbonyl, C 3 -C 6 alkylcarbonylalkyl, C 1 -C 6 alkylthio, C 1 -C 6 haloalkylthio, C 1 -C 6 alkylsulfinyl, C 1 -C 6 haloalkylsulfinyl, C 1 -C 6 alkylsulfonyl, C 1 -C 6 haloalkylsulfonyl, C 1 -C 6 alkylsulfonyloxy, C 1 -C 6 haloalkylsulfonyloxy, C 1 -C 6 alkylamino, C 2 -C 6 dialkylamino, C 2 -C 6 alkylcarbonylamino, CH(═O), —NHCH(═O), —SF 5 , —SC≡N or —U—V-T;

R 32 and R 33 are each independently selected from the group consisting of H, C 1 -C 6 alkyl, and C 1 -C 6 alkoxy, C 2 -C 6 alkylcarbonyl, C 2 -C 6 haloalkylcarbonyl and C 2 -C 6 alkoxycarbonyl;

each R 34 is independently C 1 -C 7 alkyl or C 1 -C 7 alkoxy;

each a and b are independently 0, 1 or 2 in each instance of S(═O) a (═NR 8 ) b , provided that the sum of a and b is 0, 1 or 2;

each m, p, r and s is independently 0, 1 or 2;

each n, t and u is independently 1 or 2; and

Z is O or S.

2 . A compound of claim 1 wherein:

R 1 is Br, Cl or F;

W is C(═O);

R 1 is H, C 1 -C 6 alkyl or -L(CR 5a R 5b ) m Q 1 ;

L is a direct bond;

R 5a and R 5b are H;

m is 0;

Q 1 is phenyl optionally substituted with 1 substituent selected from R 6a ;

R 6a is —C 1 -C 6 alkyl or C 1 -C 6 haloalkyl;

G is C(═O);

A is N(R 7a );

R 7a is H, C 1 -C 6 alkyl or C(═Z)R 15 ;

Z is O;

R 15 is C 1 -C 6 alkyl, C 1 -C 6 alkoxy or an unsubstituted phenyl ring;

R 2 is (CR 31a R 31b ) r Q 2 and Q 2 is a phenyl ring optionally substituted with up to 3 substituents independently selected from R 8a ;

each R 8a is independently selected from the group consisting of halogen, C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, cyano, —SF 5 , C 1 -C 6 alkoxy, C 1 -C 6 haloalkoxy, C 1 -C 6 haloalkylthio, C 1 -C 6 halosulfonyl, and a phenyl or phenoxy ring optionally substituted with up to 3 substituents independently selected from R 27 ;

each R 27 is independently selected from halogen;

R 3 is OR 9 , OC(═Z)R 10 , OS(═O) u R 11 or halogen;

R 10 is —C 1 -C 6 alkyl, C 1 -C 6 haloalkyl, or phenyl optionally substituted with up to 3 substituents each independently selected from R 28 ;

R 11 is selected from C 1 -C 6 alkyl or phenyl optionally substituted with up to 3 substituents each independently selected from R 29 .

R 29 is C 1 -C 4 alkyl; and

R 4 is H, halogen, C 1 -C 6 alkyl, C 1 -C 6 alkoxy or phenyl optionally substituted with up to 3 substituents independently selected from R 26 .

3 . A compound of claim 2 wherein R 1 is H or C 1 -C 3 alkyl;

R 7a is H or C(═Z)R 15 ;

R 15 is C 1 -C 6 alkyl;

R 2 is Q 2 is a phenyl ring substituted with up to 2 substituents each independently selected from R 8a ;

each R 8a is independently selected from the group consisting of F, Cl, Br, CH 3 , CF 3 , cyano, —SF 5 , OCH 3 , OCF 3 , OCHF 2 , OCF 2 CHF 2 , —SCF 3 , —S(═O) 2 CH 3 and a phenyl or phenoxy ring optionally substituted with up to 3 substituents each independently selected from R 27 ;

each R 27 is independently selected from halogen;

R 3 is OR 9 ; and

R 4 is selected from the group consisting of H, Cl, CH 3 , OCH 3 and unsubstituted phenyl.

4 . A compound of claim 3 wherein R 1 is H or CH 3 ;

R 7a is H;

each R 8a is independently selected from the group consisting of F, Cl, Br, CF 3 , OCH 3 and OCF 3 ;

R 3 is OH; and

R 4 is H.

5 . A compound of claim 4 wherein R 1 is CH 3 ;

R 2 is phenyl, substituted with 1 R 8a substituent; and

R 8a is CF 3 or OCF 3 .

6 . A compound of Formula 1 wherein W is C(═O), G is C(═O), A is NH, R 1 is CH 3 , R 2 is phenyl substituted with F, R 3 is OH and R 4 is H; or

W is C(═O), G is C(═O), A is NH, R 1 is CH 3 , R 2 is phenyl substituted with Cl, R 3 is OH and R 4 is H; or

W is C(═O), G is C(═O), A is NH, R 1 is CH 3 , R 2 is phenyl substituted with Br, R 3 is OH and R 4 is H; or

W is C(═O), G is C(═O), A is NH, R 1 is CH 3 , R 2 is phenyl substituted with CF 3 , R 3 is OH and R 4 is H; or

W is C(═O), G is C(═O), A is NH, R 1 is CH 3 , R 2 is phenyl substituted with CHF 2 , R 3 is OH and R 4 is H; or

W is C(═O), G is C(═O), A is NH, R 1 is CH 3 , R 2 is phenyl substituted with CH 3 , R 3 is OH and R 4 is H; or

W is C(═O), G is C(═O), A is NH, R 1 is CH 3 , R 2 is phenyl substituted with OCH 3 , R 3 is OH and R 4 is H; or

W is C(═O), G is C(═O), A is NH, R 1 is CH 3 , R 2 is phenyl substituted with OCF 3 , R 3 is OH and R 4 is H; or

W is C(═O), G is C(═O), A is NH, R 1 is CH 3 , R 2 is phenyl substituted with CN, R 3 is OH and R 4 is H; or

W is C(═O), G is C(═O), A is NH, R 1 is CH 3 , R 2 is phenyl substituted with SF 5 , R 3 is OH and R 4 is H; or

W is C(═O), G is C(═O), A is NH, R 1 is CH 3 , R 2 is phenyl substituted with OCF 3 , R 3 is OSO 2 Me and R 4 is H; or

W is C(═O), G is C(═O), A is NH, R 1 is CH 3 , R 2 is phenyl substituted with OCHF 2 , R 3 is OSO 2 Me and R 4 is H; or

W is C(═O), G is C(═O), A is NH, R 1 is CH 3 , R 2 is phenyl substituted with CN, R 3 is OSO 2 Me and R 4 is H; or

W is C(═O), G is C(═O), A is NH, R 1 is CH 3 , R 2 is phenyl substituted with F, R 3 is OSO 2 Me and R 4 is H; or

W is C(═O), G is C(═O), A is NH, R 1 is CH 3 , R 2 is phenyl substituted with Br, R 3 is OSO 2 Me and R 4 is H; or

W is C(═O), G is C(═O), A is NH, R 1 is CH 3 , R 2 is phenyl substituted with Cl, R 3 is OSO 2 Me and R 4 is H; or

W is C(═O), G is C(═O), A is NH, R 1 is CH 3 , R 2 is phenyl substituted with SF 5 , R 3 is OSO 2 Me and R 4 is H; or

W is C(═O), G is C(═O), A is NH, R 1 is CH 3 , R 2 is phenyl substituted with CF 3 , R 3 is OSO 2 Me and R 4 is H; or

W is C(═O), G is C(═O), A is NH, R 1 is CH 3 , R 2 is phenyl substituted with OCH 3 , R 3 is OSO 2 Me and R 4 is H; or

W is C(═O), G is C(═O), A is NH, R 1 is CH 3 , R 2 is phenyl substituted with CH 3 , R 3 is OSO 2 Me and R 4 is H.

7 . A compound of claim 1 which is selected from the group:

2,3-Dihydro-5-hydroxy-2-methyl-3-oxo-N-[4-(trifluoromethoxy)phenyl]-4-pyridazinecarboxamide;

2,3-Dihydro-2-methyl-5-[(methylsulfonyl)oxy]-3-oxo-N-[4-(trifluoromethoxy)phenyl]-4-pyridazinecarboxamide;

2,3-Dihydro-5-hydroxy-2-methyl-3-oxo-N-[4-(trifluoromethyl)phenyl]-4-pyridazinecarboxamide;

N-[4-(Difluoromethoxy)phenyl]-2,3-dihydro-5-hydroxy-2-methyl-3-oxo-4-pyridazinecarboxamide;

N-[2-Fluoro-4-(trifluoromethyl)phenyl]-2,3-dihydro-5-hydroxy-2-methyl-3-oxo-4-pyridazinecarboxamide;

N-(4-Bromophenyl)-2,3-dihydro-5-hydroxy-2-methyl-3-oxo-4-pyridazinecarboxamide;

[4-[[[2,3-Dihydro-5-hydroxy-2-methyl-3-oxo-4-pyridazinyl]carbonyl]amino]phenyl]pentafluorosulfur;

N-[4-(Difluoromethoxy)phenyl]-2,3-dihydro-2-methyl-5-[(methylsulfonyl)oxy]-3-oxo-4-pyridazinecarboxamide;

N-(4-cyanophenyl)-2,3-dihydro-2-methyl-5-[(methylsulfonyl)oxy]-3-oxo-4-pyridazinecarboxamide;

[4-[[[2,3-Dihydro-2-methyl-5-[(methylsulfonyl)oxy]-3-oxo-4-pyridazinyl]carbonyl]amino]phenyl]pentafluorosulfur;

2,3-Dihydro-2-methyl-5-[(methylsulfonyl)oxy]-3-oxo-N-[4-(trifluoromethyl)phenyl]-4-pyridazinecarboxamide;

5-Chloro-2,3-dihydro-2-methyl-3-oxo-N-[4-(trifluoromethoxy)phenyl]-4-pyridazinecarboxamide;

5-Bromo-2,3-dihydro-2-methyl-3-oxo-N-[4-(trifluoromethoxy)phenyl]-4-pyridazinecarboxamide; and

6-Methyl-3-[(trifluoromethoxy)phenyl]-2H-pyridazino[4,5-e]-1,3-oxazine-2,4,5(3H,6H)-trione.

8 . A fungicidal composition comprising (a) a compound of claim 1 ; and (b) at least one other fungicide.

9 . A fungicidal composition comprising (a) a compound of claim 1 ; and (b) at least one additional component selected from the group consisting of surfactants, solid diluents and liquid diluents.

10 . A method for controlling plant diseases caused by fungal plant pathogens comprising applying to the plant or portion thereof, or to the plant seed, a fungicidally effective amount of a compound of claim 1 .