Patent GB-867780-A (GB)
Title: New dithiophosphoric acid esters and pesticidal compositions comprising them
Inventor: PIANKA MAX
IPC: C07F9/165
Filed: 1957-11-08
Abstract: The invention comprises compounds of the general formula: <FORM:0867780/IV (b)/1> in which R and R1 are alkyl groups which contain 1 to 4 carbon atoms and may be the same or different, R2 is an aliphatic group which may be substituted by one or more of the following:- halogen atoms, amino groups, substituted amino groups, nitro groups, alkoxy groups and alkylthio groups, said aliphatic group containing not more than 12 carbon atoms, or is an p araliphatic group, a substituted araliphatic group, a naphthyl group or a substituted naphthyl group and R3 is a C1-C4 alkyl group or a C3 alkenyl group.  The compounds may be obtained by reacting a salt of the appropriate O,O-dialkyl dithio-phosphoric acid (or the free acid in the presence of an acid binding agent) with an appropriate N-chloro-(bromo- or iodo-) acetyl N-substituted carbamic acid ester preferably in a solvent medium.  Suitable salts are alkali metal and ammonium salts and suitable acid binding agents are alkali metal carbonates such as sodium or potassium carbonate and tertiary bases such as pyridine and triethylamine.  Suitable solvents are water, ketones, alcohols, ethers (including dioxane), hydrocarbons and halogenated hydrocarbons.  Examples are given for the production of compounds of the above formula in which R and R1 are each ethyl, R2 and R3 are each CH3; R2 is C2H5 and R3 is CH3, C2H5, iso C3H7, allyl, and n-C4H9 respectively, R2 is n-C4H9 and R3 is CH3, and R2 is a -naphthyl and R3 is CH3.  Preferred compounds are those in which R2 is a C1-C12 alkyl group, a C3-C12 alkenyl group, a benzyl group, a p-nitrobenzyl group, a naphthyl group, a b -chloroethyl or b -fluorethyl group, a b -ethoxyethyl group, a b -ethyl thioethyl group, a dimethyl amino-ethyl or a diethylaminoethyl group.  When the compounds include basic groups in the group R2 acid addition salts, e.g. hydrochlorides or hydrogen oxalates, of such compounds may be prepared and the invention also includes such salts.  The products have insecticidal and/or acaricidal properties (see Group VI). N-chloroacetyl N-methyl methyl carbamate used as a starting material is obtained by heating a mixture of chloroacetyl chloride and N-methyl methyl carbamate.  According to the provisional specification R and R1 include alkyl radicals generally, and R2 may also be any aryl residue which may be substituted whilst R3 is defined as having the same meaning as R2.  The Specification also describes the preparation of N-chloroacetyl N-methyl (N-ethyl, N-isopropyl, and N-n-butyl) ethyl carbamate by heating the corresponding ethyl N-alkyl carbamate with chloroacetyl chloride.ALSO:A pesticidal composition comprises a compound of the general formula <FORM:0867780/VI/1> in which R and R1 are C1-C4 alkyl groups, R2 is an aliphatic group which may be substituted by one or more of the following: halogen atoms, amino groups, substituted amino groups, nitro groups, alkoxy groups, and alkylthio groups, said aliphatic group containing not more than 12 carbon atoms, or is an araliphatic group which may be substituted, a naphthyl group or a substituted naphthyl group, and R3 is a C1-C4 alkyl group or a C3 alkenyl group, or an acid addition salt of a basic compound of the above formula (see Group IV (b)), in association with a carrier or diluent.  The composition may be a solution or emulsion or may be in the form of an aerosol, dust, wettable powder, granulate, pellet, or paste or it may be a thermal fumigating mixture in which the active ingredient is associated with a solid pyrotechnic component. Other insecticides and/or non-basic fungicides may also be present.  In an example 0,0-di-ethyl S-(acetyl N-methyl methyl carbamate)-phosphoro-dithioate is mixed with a poly-ethylene glycol ether type wetting-agent, methanol is added and the solution diluted with water.  According to the Provisional Specification R and R1 may be any alkyl radical and R2 may also be any aryl radical which may be substituted whilst R3 is defined as having the same meaning as R2.