Substituted thiadiazinone dioxide and preparation method therefor, herbicidal composition, and application therefor

A substituted thiadiazinone dioxide, as shown in formula I:

• wherein,
• R1 and R2 each independently represent hydrogen, alkyl optionally substituted by halogen, alkenyl optionally substituted by halogen, alkynyl optionally substituted by halogen, cycloalkyl optionally substituted by halogen, cycloalkylalkyl optionally substituted by halogen, formylalkyl optionally substituted by halogen, hydroxyalkyl optionally substituted by halogen, aryl, arylalkyl, heterocyclyl, heterocyclylalkyl, R3—O-(alkyl)n-, R3—(CO)-(alkyl)n-, R3—(CO)—O-(alkyl)n-, R3—O-(alkyl)n-(CO)—, R3—S—(CO)-(alkyl)n-, R3—O—(CO)-(alkyl)-, R3—O—(CO)—O-(alkyl)-, R3—SO2-(alkyl)n-, R4R5N—(CO)—, R4R5N-(alkyl)n-, R3—(CO)—NR6—, or R4R5N—(CO)—NR6;
• each R3 independently represents alkyl, alkenyl, alkynyl, cycloalkyl or cycloalkylalkyl with or without halogen;
• aryl, arylalkyl, heterocyclyl or heterocyclylalkyl;
• R4, R5 and R6 each independently represent hydrogen;
• alkyl, alkenyl, alkynyl, cycloalkyl or cycloalkylalkyl with or without halogen;
• aryl, arylalkyl, heterocyclyl or heterocyclylalkyl;
• n represents 0 or 1;
• X represents hydrogen or halogen;
• Y represents C—Z or N;
• Z represents hydrogen or halogen;
• and when X represents halogen, Z represents hydrogen;
• the “aryl” or “heterocyclyl” is unsubstituted or substituted by at least one of the following groups:
• halogen, nitro, cyano, thiocyanato, cyanoalkyl, mercapto, hydroxyl, hydroxylalkyl, carboxyl, formyl, azido, trialkylsilyl, dialkylphosphono, unsubstituted or substituted heterocyclyl, heterocyclylalkyl, aryl or arylalkyl;
• alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, cycloalkylalkyl, cycloalkenylalkyl, cycloalkyl substituted by alkyl, OR″, SR″, -alkyl-OR″, —O-alkyl-OR″, -alkyl-SR″, COR″, -alkyl-COR″, —O-alkyl-COR″, COOR″, -alkyl-COOR″, —O-alkyl-COOR″, COSR″, SOR″, SO2R″, —O—SO2R″, -alkyl-SO2R″, OCOR″, -alkyl-OCOR″ or SCOR″ with or without halogen;
• amino, aminocarbonyl, aminocarbonylalkyl or aminosulfonyl which is unsubstituted or substituted by one or two groups selected from the group consisting of R″, COR″, COOR″, SO2R″, -alkyl-SO2R″ or OR″ with or without halogen;
• or any two adjacent carbon atoms in the ring are connected with —CH2CH2CH2—, —OCH2CH2—, —OCH2O—, —OCH2CH2O— or —CH═CH—CH═CH— groups to form a fused ring;
• each R″ independently represents alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkylalkyl, cycloalkenyl, cycloalkenylalkyl, and unsubstituted or substituted heterocyclyl, heterocyclylalkyl, aryl or arylalkyl.