GB952294A - Phosphorus-containing hydroquinone and quinone derivatives - Google Patents

Abstract

The invention comprises thiophosphoric acid esters of the general formula: <FORM:0952294/C2/1> wherein A is an aromatic or quinoid ring system, Alkyl is an alkyl radical containing up to 4 carbon atoms, X is a hydroxyl group in the case of an aromatic system or an oxygen atom in the case of a quinoid system and R1, R2 and R3 are hydrogen or halogen atoms or alkyl radicals containing up to 4 carbon atoms which may be substituted by halogen atoms, or are alkoxy, aryloxy, amino, alkylamino, dialkylamino, saturated heterocyclic amino, alkylcarbonylamino, alkylcarbonyl alkylamino, alkoxycarbonylamino or alkoxycarbonylalkylamino radicals or another SP(S)(OAlkyl)2 group or R2 and R3 may be linked together to form a saturated or unsaturated cyclic residue which may be interrupted by a hetero atom. They may be obtained by reacting a quinone of the general formula: <FORM:0952294/C2/2> wherein Y is a hydrogen or halogen atom and R1, R2 and R3 are as defined above with an appropriate thionothiolphosphoric acid O,O-dialkyl ester or with a salt thereof when Y is a halogen atom and, if desired, subsequently oxidising the hydroquinone derivative, when obtained, to form the quinone derivative. The reaction can be carried out in the presence of an organic solvent or diluent and generally proceeds at room temperature. Suitable solvents are methanol, ethanol, acetone, methyl ethyl ketone and benzene. When Y in the formula is hydrogen the reaction is an addition reaction and the product is a hydroquinone derivative although some quinone starting materials yield quinhydrones as products. The hydroquinones and quinhydrones can be oxidised to the corresponding quinone derivatives, specified oxidising agents being p-benzoquinone, Fremy's salt and lead dioxide. The oxidation is preferably carried out in a solvent or diluent at room temperature, with cooling, or at a slightly elevated temperature. When Y is halogen the reaction will either take place with the splitting off of hydrogen halide to form a quinone derivative or, in certain cases and provided the quinone nucleus contains at least one free position, an addition reaction takes place, thus O,O-dimethyldithiophosphate reacts with 2,5-dichloro-benzoquinone-(1, 4) by addition to form a hydroquinone derivative. The products are useful as intermediates for pharmaceuticals, as pest control agents and as ingredients of veterinary medicines (see Division A5).ALSO:A pest control or veterinary composition comprises a solid or liquid carrier, or diluent and a hydroquinone or quinone derivative of the general formula:- <FORM:0952294/A5-A6/1> wherein A is an aromatic or quinoid ring system, alkyl is a C1-C4 alkyl radical, X is a hydroxyl group in the case of an aromatic system or an oxygen atom in the case of a quinoid system and R1, R2 and R3 are hydrogen, or halogen atoms or C1-C4 alkyl radicals which may be substituted by halogen atoms, or are alkoxy, aryloxy, amino, alkylamino, dialkylamino, saturated heterocyclic amino, alkylcarbonylamino, alkylcarbonyl alkylamino, alkoxycarbonylamino or alkoxycarbonylalkylamino radicals or another SP(S)(OAlkyl)2 group wherein alkyl is a C1-C4 alkyl group, or R2 and R3 may be linked together to form a saturated or unsaturated cyclic residue which may be interrupted by a hetero atom. A typical pesticidal composition is obtained by mixing the compound:- <FORM:0952294/A5-A6/2> with dimethyl formamide, adding a benzyl hydroxydiphenyl polyglycol ether as emulsifier and then diluting with water.