2-(substituted phenyl)-6-amino-5-alkoxy, thioalkoxy and aminoalkyl-4-pyrimidinecarboxylates and their use as herbicides

1. A compound of the formula I

wherein

Q represents a C 1 -C 4 alkoxy, C 1 -C 4 haloalkoxy, C 1 -C 4 thioalkoxy, C 1 -C 4 halothioalkoxy or —NR 3 R 4 ;

R 1 and R 2 independently represent H, C 1 -C 6 alkyl, C 3 -C 6 alkenyl, C 3 -C 6 alkynyl, hydroxy, C 1 -C 6 alkoxy, amino, C 1 -C 6 acyl, C 1 -C 6 carboalkoxy, C 1 -C 6 alkylcarbamyl, C 1 -C 6 alkylsulfonyl, C 1 -C 6 trialkylsilyl or C 1 -C 6 dialkyl phosphonyl or R 1 and R 2 taken together with N represent a 5- or 6-membered saturated ring;

Ar represents a phenyl group substituted with one to four substitutents selected from halogen, nitro, cyano, formyl, C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 1 -C 6 alkoxy, C 2 -C 4 alkoxyalkyl, C 2 -C 6 alkylcarbonyl, C 1 -C 6 alkythio, C 1 -C 6 alkylsulfinyl, C 1 -C 6 alkylsulfonyl, C 2 -C 4 alkenyloxy, C 2 -C 4 alkynloxy, C 2 -C 4 alkenylthio, C 2 -C 4 alkynylthio, C 1 -C 6 haloalkyl, C 2 -C 6 haloalkenyl, C 2 -C 6 haloalkynyl, C 1 -C 6 haloalkoxy, C 2 -C 4 haloalkoxyalkyl, C 2 -C 6 haloalkylcarbonyl, C 1 -C 6 haloalkythio, C 1 -C 6 haloalkylsulfinyl, C 1 -C 6 haloalkylsulfonyl, C 3 -C 6 trialkylsilyl, C 2 -C 4 haloalkenyloxy, C 2 -C 4 haloalkynyloxy, C 2 -C 4 haloalkenylthio, C 2 -C 4 haloalkynylthio, —OCH 2 CH 2 —, —OCH 2 CH 2 CH 2 —, —OCH 2 O—, —OCH 2 CH 2 O—, —C(O)OR 4 , —C(O)NR 3 R 4 , —CR 3 NOR 4 , —NR 3 R 4 , —NR 3 R 4 , —NR 3 SO 2 R 4 , —NR 3 C(O)R 4 , —NR 3 C(O)OR 4 , —NR 3 C(O)NR 3 R 4 or —NCR 3 NR 3 R 4 ;

R 3 represents H, C 1 -C 4 alkyl or C 1 -C 4 haloalkyl; and

R 4 represents C 1 -C 4 alkyl or C 1 -C 4 haloalkyl;

and agriculturally acceptable derivatives of the carboxylic acid group.

2. A compound of claim 1 in which R 1 and R 2 independently represent H or C 1 -C 6 alkyl.

3. A compound of claim 1 in which the agriculturally acceptable derivatives of the carboxylic acid group are agriculturally acceptable salts, esters and amides.

4. A compound of claim 1 in which Ar represents para-substituted phenyl with or without other substituents.

5. A compound of claim 1 in which Q represents methoxy.

6. A herbicidal composition comprising a herbicidally effective amount of a compound of Formula I, according to claim 1 , in a mixture with an agriculturally acceptable adjuvant or carrier.

7. A method of controlling undesirable vegetation which comprises contacting the vegetation or the locus thereof with or applying to the soil to prevent the emergence of vegetation an herbicidally effective amount of a compound of Formula I, according to claim 1 .