GB748422A - Thiadiazole derivatives and compositions containing them - Google Patents

Abstract

The invention comprises compounds of formula <FORM:0748422/IV(a)/1> wherein R denotes a benzyl radical bearing one or more halogen atoms or nitro groups as substituents in the benzene nucleus. The compounds are prepared by heating a compound R-halogen, where the halogen is preferably chlorine, with 2 : 5-dimercapto-1 : 3 : 4-thiadiazole in presence of an alkaline condensing agent, e.g. sodium or potassium hydroxide, and preferably in an anhydrous medium. The examples describe the preparation of 2 : 5-bis-41-nitrobenzylthio- and 2 : 5-bis-41-chlorobenzylthio-1 : 3 : 4-thiadiazole.ALSO:An acaricidal composition comprises a compound of formula <FORM:0748422/VI/1> wherein R denotes a benzyl radical which is either unsubstituted or bears one or more halogen atoms (preferably chlorine) or nitro groups as substituents in the benzene nucleus, together with a diluent or carrier. The composition may have the form of a dust, dispersion, emulsion or a solution giving a mist or aerosol. Diluents, carriers and ancillary substances specified are pulverulent solids (e.g. kaolin); water; water miscible organic solvents (e.g. acetone); paraffin oils (e.g. white oil); aromatic hydrocarbons boiling within the range 80-300 DEG C. (e.g. benzene, xylene); wetting, dispersing, suspending and emulsifying agents; magnesium sulphate; and mixtures of a non-volatile oil (e.g. vegetable oil) and a miscible volatile supplementary solvent (e.g. cyclohexanone or acetone) preferably incorporating a volatile propellant (e.g. a mixture of chloro-fluoroderivatives of methane and ethane).