Patent GB-597391-A (GB)
Title: Manufacture of insecticidal compositions and the resulting products
Filed: 1943-08-25
Abstract: Compounds of the general formula:  <FORM:0597391/IV/1> wherein R1 and R2 are the same or different aromatic nucleii one of which must contain substituents of non-salt-forming type, X1 is hydrogen or a halogen-free aliphatic hydrocarbon radicle and X2 is a halogen-free hydrocarbon radicle, are obtained by condensing compounds of the benzene series selected according to definition, with aliphatic aldehydes or ketones or the corresponding halides in the presence of condensation agents, such as aluminium chloride, zinc chloride, hydrochloric acid or sulphuric acid.  Indirect methods of production by which the nuclear substituents are changed may also be used.  In examples: (1) chlorobenzene is condensed with acetaldehyde to produce as-4 : 41-dichlorodiphenyl ethane; (2) as-4 : 41-dimethyldephenylethane, as-3 : 4 : 31 : 41-tetrachlorodiphenylethane, and as-3 : 4 : 31 : 41-tetramethyldiphenyl ethane are produced as in (1); chlorobenzene is condensed with 2 : -dichloropropane to produce 2 : 3-bis-(p-chlorophenyl)-propane; (4) chlorobenzene is condensed with oenanthaldehyde to produce 1 : 1-bis-(p-chlorophenyl)-heptane. Analgous compounds are obtained using isobutylaldehyde, isovaleraldehyde or trimethylacetaldehyde instead of oenanthaldehyde.ALSO:Solid insecticidal compositions are obtained by admixing a compound of the general formula <FORM:0597391/VI/1> wherein R1 and R2 indicate the same or different aromatic nucleii, one of which must contain substituents of non-salt-forming type, X1 indicates hydrogen or a halogen-free aliphatic hydrocarbon radical and X2 indicates a halogen-free hydrocarbon radical, with a solid finely-divided or porous, inert diluent or carrier.  Further substituents, e.g. nitrothiocyano and alkoxy may be present in the aromatic part of the molecule.  The active insecticidal ingredient is admixed in solid form or dissolved in a solvent which must be expelled finally from the resulting mixture with an inert diluent, e.g. bentonite.  Other fungicidal, bactericidal or insecticidal ingredients may be added.  In examples: (1) talcum powder, pumicestone, charcoal or kieselguhr is steeped in as-4 : 41-dichloro-diphenyl-ethane, dried and milled to produce an insecticidal powder; (2) as-4 : 41-dimethyldiphenyl ethane, as-3 : 4 : 31 : 41-tetra-chlorodiphenyl ethane and as-3 : 4 : 31 : 41-tetra-methyldiphenyl ethane are used in compositions as in (1); (3) 2 : 2-bis-(p-chlorophenyl)-propane, the corresponding bromo compound or analogous condensation products of other ketones such as di-aryl derivatives of methyl-ethyl ketone, diethyl ketone, isovalerone and laurone are used in compositions as in (1); (4) 1 : 1-bis-(p-chlorophenyl)-heptane and analogous compounds produced by condensing chlorobenzene with isobutylaldehyde, isovaleraldehyde or trimethylacetaldehyde, are used in compositions as in (1); (5) bole is soaked in as-4 : 41-dichloro-diphenyl ethane, dried and ground. Wetting agents may be added to the powder thus obtained; (6) magnesium oxide is treated with as-bis-(4-methylphenyl)-ethane; (7) calcium carbonate is treated with as-4 : 41-dichloro-diphenyl ethane and dried.  The powder thus obtained is admixed with sodium carbonate and a wetting agent.  The Provisional Specification also describes the use of compounds in which R1 and R2 are located on different carbon atoms.