Coumaranyl-n-methyl-carbamic acid esters and their use in insecticidal compositions

• Main Authors: HAMMANN INGEBORG, HEISS RUDOLF, BEHRENZ WOLFGANG
• Format: Patent
• Language: English
• Published: 03.01.1968
• Subjects: CHEMISTRY; HETEROCYCLIC COMPOUNDS; METALLURGY; ORGANIC CHEMISTRY

The invention comprises the compounds of formula <FORM:1097970/C2/1> wherein R is H or CH3. The compounds are prepared by reacting compounds of formula <FORM:1097970/C2/2> with (a) methyl isocyanate; (b) an excess of phosgene to give the corresponding chloroformic acid esters and then with methylamine; or (c) an equivalent amount of phosgene to give the bis-(7-coumaranyl)-carbonate and then with methylamine. The compounds are used in insecticidal compositions (see Divisions A5-A6). 2,3 - Dimethyl - 7 - hydroxycoumaran is prepared by reacting catechol with crotyl bromide to yield catechol monocrotyl ether, rearranging this by heating to 180 DEG C. to yield 3-alpha-methyl-allyl-catechol and treating this with HBr in glacial acetic acid.ALSO:Insecticidal compositions containing as active ingredients coumararyl-N-methyl carbamic acid esters of formula <FORM:1097970/A5-A6/1> wherein R is H or CH3. The compositions may be in the form of solutions, emulsions, suspensions, powders, pastes. Specified auxiliaries include liquids, e.g. water, xylene, benzene, chlorobenzenes, paraffins, methanol, butanol, ethanolamine and dimethylformamide; solids, e.g. kaolin, alumina, talc, chalk, silicic acid and silicates; emulsifiers, e.g. polyoxyethylene-fatty acid esters, polyoxyethylene fatty alcohol ethers and alkyl or aryl sulphonates; dispersing agents, e.g. lignin, sulphite waste liquors and methylcellulose. In Examples the effect of the compositions on mosquitoes, house flys, moth and butterfly caterpillars, aphids, spider mites and horse radish beetles and their larvae is described.