Process for the preparation of insecticidal compositions based on carbamic esters

An insecticidal composition in the form of a liquid organic homogeneous solution comprising as essential components (A) from about 0.01 to 10%, based on the weight of the composition, of an ortho-substituted phenyl N-methyl-carbamate of the following formula:

• ##STR4## wherein R is an unsubstituted 1,3-dioxolan-2-yl radical or substituted by one or two methyl groups;
• and as sole solvent carrier for said component (A) a homogeneous mixture essentially consisting of
• B. from about 0.01 to 10%, based on the weight of the composition of an organic diluent which is selected from the group consisting of vaseline oil, paraffin oil, hexadecane, 1-chlorohexadecane, 1-bromotetradecane, tetrachlorodiphenyl, isopropylmyristate, di(2-ethylhexyl) adipate, dibutylphthalate, dioctylphthalate, 5-(3,6,9-trioxa-undecyl-2-oxy)-1,3-benzodioxole, glycerol, 5,8,11-trioxapentadecane, 2-amino-2-ethyl-1,3-propanediol, ter.dodecanethiol, oleone, octanoic acid, oleic acid, 2-dodecylsuccinic acid anhydride, olive oil, line oil and mixtures thereof, the weight proportion between component B and component A ranging between 0.2 and 10, with component B having a maximum dissolving capacity for component A of 5%, by weight, at 20.degree. C. and
• C. from about 25 to 99%, based on the weight of the composition, of an organic solvent, which is selected from the group consisting of dichloromethane, trichloromethane, methylacetate, ethylacetate, propylacetate, isopropylacetate, butylacetate, isobutylacetate, sec. butylacetate, methylpropionate, ethylpropionate, methylbutyrate, ethylbutyrate, 2-methoxyethyl acetate, tetrahydrofuran, dioxan, 2-methoxy-ethanol, methanol, ethanol, isopropanol, acetone, methyl-ethyl-ketone, nitromethane and acetonitrile, with component C having a dissolving capacity for component A of at least 5%, by weight, at 20.degree. C. and
• D. from 0 to about 75%, based on the weight of the composition of an organic diluent which is selected from the group consisting of pentane, hexane, heptane, 1-chlorobutane, 1,1,1-trichloroethane, trichloroethylene, benzene, isopropanol, amyl alcohol and light petroleum fractions having a distillation range between about 70.degree. and 250.degree. C. and which are soluble in A + B + C liquid at 25.degree. C, have a vapour pressure at 25.degree. C between 0.01 and 150 Torr and are able to dissolve at 20.degree. C between 0 and 5%, by weight, of component A.