Patent GB-653027-A (GB)
Title: Manufacture of insect-repelling amides of chlorobenzoic acid and compositions prepared therefrom
IPC: C07C233/00
Filed: 1948-06-05
Abstract: Chlorobenzamides of formula <FORM:0653027/IV (b)/1> where R is ethyl or allyl and X is hydrogen or chlorine are prepared by (1) reacting a compound <FORM:0653027/IV (b)/2> with a compound Y1NR2, where Y=OH and Y1=H; Y=Cl or OAcyl and Y1=H; Y=Cl and Y1=Na; Y=Cl and Y1=HCl.H; Y= OMe and Y1=H; Y=NH2 and Y1=H; Y= ONa and Y1=ClCO-; or Y=ONa and Y1= Aryl SO2-, e.g. p-MeC6H4SO2-; (2) reducing the nitro group of the corresponding o-nitrobenzamide (which may be prepared from the corresponding o-nitrobenzoic acid chloride and the amine NHR2) to an amino group, diazotizing and converting by the Sandmeyer method to a chloro group; and (3) alkylating the compound <FORM:0653027/IV (b)/3> where Z is hydrogen, ethyl or allyl, to introduce an ethyl or allyl group.  In the examples, 2-chlorobenzoyldiethylamide is prepared by the reaction of diethylamine with (1) and (2) o-chlorobenzoyl chloride (prepared by chlorination of o-chlorobenzaldehyde with chlorine or thionyl chloride) or (3) methyl o-chlorobenzoate; by the reaction of (4) sodium 2-chlorobenzoate with diethylcarbamyl chloride; (5) o-chlorobenzoic acid with p-toluene-N-diethylsulphonamide; it is also prepared (6) from 2-nitrobenzoyldiethylamide (prepared from 2-nitrobenzoyl chloride and diethylamine) by reduction of the nitro group, diazotization, and reaction with aqueous cuprous chloride.ALSO:Chlorobenzamides of the formula. <FORM:0653027/VI/1> where X is hydrogen or chlorine and R is ethyl or allkyl are used as the active ingredient in insect-repelling compositions.  They may be admixed with powders such as calcium phosphate or carbonate, kaolin, magnesia, boric acid, cork or wood meal, talc, and starch powder; alternatively they may be used as solutions in alcohols, e.g. ethanol, propanols, benzyl alcohol, glycerol and cyclohexanol esters, e.g. ethyl acetate, ethers, e.g. glycol monoethyl ether, ketones, e.g. propanone and butanone 2 and cyclohexanone, oils such as olive, arachis, castor and paraffin oils, kerosenes and alkyl and hydrogenated naphthalenes.  The benzamides may be emulsified in water with emulsifiers and wetting agents, or blended into ointments with walrus fat, wool grease, fatty alcohols, petroleum jelly, lipoids, stearins, fatty acid salts, thiethanolamine, fatty alcohol sulphonates, cellulose ethers, vegetable mucilages, aluminium hydroxide gel, silica gel, zinc and titamium oxides, with solvents if desired.  The benzamides in solution or emulisified may be used to impregnate textiles.  The benzamides may be dissolved in liquids such as dichlorodifluoromethane to produce aerosol sprays, or mixed with charcoal, cellulose and potassium nitrate for a fumigation composition.  Other substances which may be included in these benzamide compositions are phthalate esters, 2-ethylhexanediol-1: 3 x: x-dimethyl-x 1-carbobutoxydihydropyran, crotonic acid N-ethyl-o-toluidide, menthyl salicylate or anthranilate, phenyl salicylate, quinine salts, umbelliferone, aesculin, naphtholsulphonic acid salts, soluble calcium, magnesium and strontium salts, perfumes, and anti-oxidants.  In the examples, chlorobenzamides (e.g. o-chlorobenzoyl-N-diethylamide) is compounded with (1) talc, (2) castor oil and isopropanol, (3) water using a fatty acid sulphonate, (4) paraffin oil, stearic acid, wool grease, wax, glycerol, triethanolamine, water, and ammonia.