Abstract: A process for the production of hydroxy-substituted oxazolidinones, particularly 5-hydroxyoxazolidinones, which are useful as intermediates in the synthesis of herbicidally active compounds, comprising treating a hydroxythiazolidinone with an oxidizing agent.

Abstract: A herbicidal compound of formula (I) ##STR1## or a salt, tautomer or cyclic derivative thereof; where R.sup.1 and R.sup.2 are hydrogen and A is an optionally substituted saturated or unsaturated chain or ring of three carbon atoms.Methods for preparing these compounds, intermediates used in the preparation and herbicidal compositions containing them are also described and claimed.

Abstract: A process for the synthesis of a compound of general formula II: ##STR1## wherein: R.sup.2 and R.sup.3 are each independently hydrogen or C.sub.1 -C.sub.4 alkyl;A is an aromatic or heteroaromatic ring system optionally substituted with one or more substituents as defined herein; and in which any ring nitrogen atom may be quaternised or oxidised;alternatively, any two substituents of the group A may combine to form a fused 5- or 6-membered saturated or partially saturated carbocyclic or heterocyclic ring in which any carbon or quaternised nitrogen atom may be substituted with any of the groups defined herein for A or in which a ring carbon atom may be oxidised;the process comprising cyclising a compound of general formula VII: ##STR2## wherein A, R.sup.2 and R.sup.3 are as defined for general formula II, R.sup.20 is hydrogen, benzyl or benzyl substituted with up to five substituents selected from halo, C.sub.1 -C.sub.6 alkyl, O(C.sub.1 -C.sub.6 alkyl) or nitro and R.sub.21 is C.sub.1 -C.sub.

Abstract: A process for the preparation of a compound of general formula II: ##STR1## wherein R.sup.1 is hydrogen, or C.sub.1 -C.sub.10 hydrocarbyl or heterocyclyl having 3 to 8 ring atoms, either of which may optionally be substituted; each R.sup.2, R.sup.3, R.sup.4 and R.sup.5 is independently hydrogen or C.sub.1 -C.sub.4 alkyl; A is an optionally substituted aromatic or heteroaromatic ring system; and R.sup.21 is hydrogen, halogen, OH or OCONHR.sup.1, wherein R.sup.1 is as defined above; the process comprising cyclizing a compound of general formula III: ##STR2## wherein A, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.21 are as defined in general formula II and R.sup.25 is a leaving group such as a halogen atom; under basic conditions.

Abstract: Dihydrotetrazolo [1,5-a] quinazolines having the formula: ##STR1## wherein (a) n is 0, X is oxygen, and R is optionally unsubstituted alkyl, alkenyl of at least 4 carbon atoms, alkynyl, aryl, aralkyl, alkylthio, cycloalkyl, amino or substituted aryl; or (b) n is 1 or 2, X is oxygen, R is hydrogen, or optionally-substituted alkyl, alkenyl, alkynyl, aryl, aralkyl, alkylthio, cycloalkyl, or amino, and R.sup.1 is hydroxy, halogen, nitro, alkyl or alkoxy or (c) n is 0, 1 or 2, X is sulphur, R is hydrogen, or optionally-substituted alkyl, alkenyl, alkynyl, aryl, aralkyl, alkylthio, cycloalkyl, or amino, and R.sup.1 is hydroxy, halogen, nitro, alkyl or alkoxy; or (d) n is 0, 1 or 2, X is NR.sub.2 where R.sub.2 is hydrogen, alkyl having 1 to 10 carbon atoms, benzyl or hydroxyalkyl, R is optionally-substituted alkyl, alkenyl, alkynyl, aryl, aralkyl, alkylthio, cycloalkyl, or amino, and R.sup.1 is hydroxy, halogen, nitro, alkyl or alkoxy; and salts thereof. These compounds demonstrate pesticidal activity.

Abstract: Pesticidal tetrazole derivatives having the formula: ##STR1## wherein n is 0, 1, 2, 3 or 4; R.sup.1 is OH, halogen, alkyl, alkoxy, alkylthio, alkylsulphonyl, NO.sub.2, NH.sub.2 (optionally substituted), acyl, aroyl, CN, carboxy or sulphonic-acid or -ester or -amide; R.sup.2 is hydrogen or optionally-substituted alkyl; R.sup.3 and R.sup.4 are hydrogen or optionally-substituted alkyl, aryl, cycloalkyl or acetyl but R.sup.4 is not aryl or cycloalkyl if R.sup.3 is one of these two groups; and salts thereof when R.sup.2 is hydrogen.

Abstract: Dihydrotetrazolo [1,5-a] quinazolines having the formula ##STR1## wherein (a) n is zero, X is oxygen, and R is optionally unsubstituted alkyl, alkenyl of at least 4 carbon atoms, alkynyl, aryl, aralkyl, alkylthio, cycloalkyl, amino or substituted aryl; or (b) n is 1 or 2, X is oxygen, R is hydrogen, or optionally-substituted alkyl, alkenyl, alkynyl, aryl, aralkyl, alkylthio, cycloalkyl, or amino, and R.sup.1 is hydroxy, halogen, nitro, alkyl or alkoxy or (c) n is zero, 1 or 2, X is sulphur, R is hydrogen, or optionally-substituted alkyl, alkenyl, alkynyl, aryl, aralkyl, alkylthio, cycloalkyl, or amino, and R.sup.1 is hydroxy, halogen, nitro, alkyl or alkoxy; or (d) n is 0, 1 or 2, X is NR.sub.2 where R.sub.2 is hydrogen, alkyl having 1 to 10 carbon atoms, benzyl or hydroxyalkyl, R is optionally-substituted alkyl, alkenyl, alkynyl, aryl, aralkyl, alkylthio, cycloalkyl, or amino, and R.sup.1 is hydroxy, halogen, nitro, alkyl or alkoxy; and salts thereof. These compounds demonstrate pesticidal activity.