| 摘要 |
The invention relates to polysubstituted butanoic acids, esters and derivatives thereof which have been found to be useful as herbicides in the control of undesirable mono- and di-cotyledonous plants. The active compounds have the formula: …<CHEM>… wherein R1 is OH, OR4, NR5R6 or OM; R2 and R3 each represent a member selected from the group consisting …<CHEM>… pyridyl and thienyl; R4 is alkyl C1-C8, monohaloalkyl C1-C4, monohaloalkynyl C3-C4, monohaloalkenyl C3-C4, alkoxy C1-C4 alkyl C1-C4 or hydroxyalkynyl C2-C4; R5 and R6 each independently represent members selected from the group consisting of H and alkyl C1-C2; M is an alkali metal, ammonium, C1-C8 mono or di-alkylammonium or hydroxyethylammonium; and X and Y each independently represent members selected from the group consisting of hydrogen, halogen, alkyl C1-C4; alkoxy C1-C4, OCF3, OCHF2, CF3, CN, COOH, NO2, OH, SCH3, NR7R8, CH3SO2, and when X and Y are taken together they may represent -OCH2O- jointed to adjacent positions of the benzene ring and R7 and R8 are each hydrogen or alkyl (C1-C2). Compounds of formula (I) exist in threo and erythro stereoisomeric forms, and in general the threo isomers (many of which are novel compounds) are the more active herbicidal agents. Accordingly it is generally preferred to employ the threo stereoisomers and threo-erythro mixtures. |
