Abstract: A process for producing 2,3,5,6-tetrachloro-1, 4-benzenedicarboxylic acid, comprising heating 2,3,5,6-tetrachloro-1,4-benzenedicarboxamide together with sulfuric acid exhibiting an acidity function (—Ho) of 10.27 to 14.44 in the presence of water contained in an amount smaller than a stoichiometric value of hydrolysis at 110 to 190° C. This process efficiently produces 2,3,5,6-tetrachloro-1,4-benzenedicarboxylic acid which is a precursor of dimethyl 2,3,5,6-tetrachloro-1,4-benzenedicarboxylate useful as a herbicide.

Abstract: A process for producing 2,3,5,6-tetrachloro-1,4-benzenedicarboxylic acid, comprising heating 2,3,5,6-tetrachloro-1,4-benzenedicarboxamide together with sulfuric acid exhibiting an acidity function (—Ho) of 10.27 to 14.44 in the presence of water contained in an amount smaller than a stoichiometric value of hydrolysis at 110 to 190° C. This process efficiently produces 2,3,5,6-tetrachloro-1,4-benzenedicarboxylic acid which is a precursor of dimethyl 2,3,5,6-tetrachloro-1,4-benzenedicarboxylate useful as a herbicide.

Abstract: Substituted aryl or heteroaryl in particular benzoyl bicycloalkanediones and related compounds, intermediates therefor, synthesis thereof, and the use of said diones for the control of weeds.

Abstract: Substituted aryl or heteroaryl in particular benzoyl bicycloalkanediones and related compounds, intermediates therefor, synthesis thereof, and the use of said diones for the control of weeds.

Abstract: Substituted aryl or heteroaryl in particular benzoyl bicycloalkane-diones and related compounds, intermediates therefor, synthesis thereof, and the use of said diones for the control of weeds.

Abstract: Compounds represented by general formula (I), herbicides or selective herbicides for paddy field containing said compounds as active ingredients, method of controlling growth of undesirable plants by applying the herbicides on places where control is desired. ##STR1## wherein A represents a --S(O)nR.sup.1 in which n is 0 or 2 and R.sup.1 represents a (substituted) lower alkyl; a cycloalkyl; a (substituted) benzyl; a (substituted) phenyl; or a --OR.sup.2 in which R.sup.2 represents a (substituted) phenyl;B represents a halogen, a nitro, a lower alkyl, or a lower alkylsulfonyl;D represents a hydrogen, a lower alkyl, a lower alkoxy, a lower alkoxymethyl, or a lower alkoxycarbonyl;E represents a halogen, a (substituted) lower alkoxy, a lower alkylthio, a (substituted) lower alkylsulfonyl, or a lower alkylsulfonyloxy.The herbicides of the present invention can prevent a wide variety of noxious weeds and further selectively prevent weeds on paddy field with considerably reduced phytotoxicities on rice plant.

Abstract: Cyclic 1-one-2-ene-3-ol compounds substituted in 2-position by an aroyl or heteroaroyl group bearing a hydrocarbylsulfonyloxy or hydrocarbylsulfonylamino substituent exhibiting herbicidal activity.

Abstract: In accordance with the present invention, there are provided novel compounds represented by the following general formula [I], and herbicides containing as their active ingredients. ##STR1## wherein X.sub.1, X.sub.2, X.sub.3 and X.sub.4 are each hydrogen, halogen or methyl, and R is hydrogen or a lower alkyl.There are also provided herbicides containing as their active ingredients compounds represented by the following general formula [II]. ##STR2## wherein R is hydrogen or a lower alkyl.