Patent GB-832230-A (GB)
Title: Heterocyclic dithiophosphate compounds
IPC: C07F9/655
Filed: 1956-08-30
Abstract: The invention comprises dithiophosphates having the general formula <FORM:0832230/IV (b)/1> in which X is oxygen or sulphur, X1 is oxygen, sulphur, or CH2, z is 1 or 2, m is an integer from 3 to 7, n is a whole number from 0 to 4, R is a C1-C4 alkyl radical, Hal is chlorine or bromine as set forth below, and the values of X, X1, z, m, n and Hal are selected from the following groups of combinations:- <TABS:0832230/IV (b)/1> The saturated compounds of Groups I-III and VIII-XVI may be prepared by reacting a compound of the formula <FORM:0832230/IV (b)/2> with Z molecular proportions of a compound of the formula <FORM:0832230/IV (b)/3> or a salt thereof, wherein X1, X, z, m and n are as defined above and the unsaturated compounds of Groups IV to VII may be prepared by pyrolyzing a compound of the formula <FORM:0832230/IV (b)/4> or by dehydrohalogenating a compound of the formula <FORM:0832230/IV (b)/5> The reaction to form the compounds of Group I to III and VIII-XVI is generally effected by heating the reactants at between 20 DEG  and 200 DEG  C. and is preferably carried out in non-aqueous media, e.g. in the presence of an organic solvent.  It is also preferable when the free dithiophosphate ester is used to carry out the reaction in the presence of a material, such as a tertiary amine or pyridine or an inorganic base, which combines with the hydrogen halide formed.  The pyrolysis reaction defined above is generally carried out by heating at between 100 DEG  and 160 DEG  C. and a solvent and polymerization inhibitor may be present.  The dehydrohalogenation process referred to is generally carried out by heating with a tertiary amine or by contacting with an aqueous solution of an alkaline material. Specified dehydrohalogenation temperatures are 0 DEG  to 160 DEG  C. The products are stated to be useful as insecticides (see Group VI). The following compounds which are used as starting materials in the examples given are prepared as follows: monochlorodithiane by adding chlorine gas to dithiane in carbon tetrachloride while maintaining a temperature of - 10 DEG  C., dichlorodithiane by adding chlorine gas to dithiane in carbon tetrachloride at 5-10 DEG  C., 3-chloro-thioxane by chlorinating thioxane in carbon tetrachloride at 0 DEG  to 10 DEG  C., tetrachloro-p-thioxane by contacting thioxane in carbon tetrachloride solution with chlorine gas at about 55-80 DEG C., tetrachlorodithiane by adding four mols. of chlorine gas to p-dithiane in carbon tetrachloride at 55-80 DEG  C., 2,3-dibromotetrahydropyran by adding bromine to dihydropyran in carbon tetrachloride at 0 DEG  C., trichlorotetrahydropyran by contacting dihydropyran with chlorine gas at about - 10 DEG  C. to form 2,3-dichlorotetrahydropyran and then contacting the latter with chlorine gas at about - 15 DEG  C., tetrachlorotetrahydropyran in which two of the chlorine atoms are in the 2- and 3-positions by contacting trichlorotetrahydropyran (prepared as above) in carbon tetrachloride with chlorine gas at about 40 DEG  to 60 DEG  C. under ultra-violet radiation, and pentachlorotetrahydropyran by contacting ultra-violet-irradiated tetrachlorotetrahydropyran in refluxing carbon tetrachloride with chlorine gas.ALSO:An insecticidal composition comprises an insecticidal adjuvant as carrier and a dithiophosphate of the general formula <FORM:0832230/VI/1> (see Group IV (b)) in which X is oxygen or sulphur, X1 is oxygen, sulphur or CH2, Z is 1 or 2, m is an integer from 3 to 7, n is a whole number from 0 to 4, R is a C1-C4 alkyl radical, Hal is chlorine or bromine as set forth below, and the values of X, X1, Z, m, n and Hal are selected from the following combinations  <TABS:0832230/VI/1> The composition may be made by dispersing the dithiophosphate in an organic solvent or in water or by diluting with a solid carrier.  The organic solvent may be an alcohol, pine oil, an hydrocarbon or difluorodichloromethane.  The composition may also be in the form of a dispersion containing a surface-active dispersing agent, and may also contain a known insecticide, e.g. toxaphene, DDT, Thanite, chlordane, wotenone or pyrethrum.