Improvements in or relating to a method of producing insecticidal compositions of matter and the insecticidal compositions of matter resulting from said method

摘要

4.7 - Methano - 3a.4.7.7a - tetrahydro - 4.5.6.7.8.8-hexachlorindene (i.e. the adduct from hexachlorcyclopentadiene and cyclopentadiene) is reacted with selenium dioxide and a carboxylic acid inert to the selenium dioxide in presence of water, thus obtaining the 1-acyloxy derivative of the starting material, which may then be reacted with hydrogen chloride in presence of water and an esterification catalyst to replace the acyloxy group by chlorine and give 4.7 - methano - 3a.4.7.7a - tetrahydro - 1.4.5.6.7.8.8-heptachlorindene. Organic acids specified are acetic, propionic, butyric, benzoic, and these may be used as solvent for the reactants, or an added solvent such as chloroform, carbon tetrachloride, benzene, toluene, hexane, pentane, and dioxane may be used. Metallic selenium formed may be removed before the second stage above. Catalysts specified are aluminium and ferric chlorides, antimony pentachloride, boron trifluoride, zinc chloride, titanium tetrachloride, hydrogen fluoride, stannic chloride, boron trichloride, aluminium bromide, sulphuric acid, phosphoric acid, and phosphorus pentoxide. An example is given, using acetic acid, and zinc chloride.