Abstract: A process is disclosed for the preparation of the herbicide ethyl .alpha.-2-dichloro-5-[4-(difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-1H-1,2 ,4-triazol-1-yl]-4-fluorobenzenepropionate by the simultaneous diazotization of 4-difluoromethyl-4,5-dihydro-3-methyl-5-oxo-1-(5-amino-2-fluoro-4-chloro-p henyl)-1H-1,2,4-triazole (the Amine) and arylation of ethyl acrylate with the diazotized Amine. In the process the following reagents are added in sequence and, under specified conditions, to a cooled, stirred solution of the Amine in acetone: cuprous chloride, hydrochloric acid, ethyl acrylate, and sodium nitrite.

Abstract: Crystalline pyrethroid isomers or enantiomer pairs are converted to more pesticidally active isomers by contacting a hydrocarbon slurry of the starting isomers with an epimerization agent selected from the group consisting of 1,1,3,3-tetramethylguanidine and 1,8-diazabicyclo[5.4.0]undec-7-ene, agitating the slurry while maintaining a temperature effective for conversion, and recovering the resulting isomers. The process typically is effective for enriching cypermethrin, and cyfluthrin.

Abstract: Hydroxamic acids are efficiently isolated from aqueous reaction media in which they are produced as solids by adding to the reaction mixture with agitation, a coalescing amount of a water insoluble organic liquid, such as a light hydrocarbon or halohydrocarbon, which is a non-solvent for the hydroxamic acids. The coalesced particles float to the surface of the medium leaving behind a clear, aqueous phase which can be drained from the reaction vessel to leave the discrete particles of hydroxamic acid. Buoyancy of the particles is assisted by adding hydrogen peroxide to the reaction mixture or by bubbling air therethrough, usually after the coalescence.

Abstract: Crystallizable pyrethroid isomers or enantiomer pairs are converted to more pesticidally active isomers by contacting a hydrocarbon slurry of the starting isomers with a base and a catalyst, the catalyst being substantially soluble in the slurry and selected from a quaternary ammonium compound, a quaternary phosphonium compound and a crown ether, agitating the slurry while maintaining a temperature effective for conversion, and recovering the resulting isomers. The tendency to form benzoin ester by-product is reduced by including in the slurry a weak base, an aldehyde scavenger such as a metabisulfite, and/or a tetraalkyl (C.sub.1 -C.sub.5) ammonium halide catalyst dissolved in an aprotic solvent such as an organic nitrile. The process typically is effective for enriching cypermethrin, cyfluthrin and (cyano (3-phenoxyphenyl)methyl 3-(2,2-dibromoethenyl)-2,2-dimethylcyclopropanecarboxylate in the more active species.

Abstract: 2-Methallyloxyphenol is produced selectively in good yield, high purity and without having to separate and recycle large amounts of catechol, in the reaction of methallyl chloride with catechol, by forming a substantially non-aqueous mixture of an alkali metal catecholate and a molar excess of methallyl chloride perferably in a polar organic solvent in which the methallyl chloride is substantially insoluble, agitating the mixture to produce a two-phase system comprising an organic first phase containing product 2-methallyloxyphenol dissolved in methallyl chloride and a polar second phase containing unreacted catecholate, and recovering product 2-methallyloxyphenol from the first plase. The presence of a quaternary ammonium or phosphonium catalyst in the reaction mixture further reduces undesired ring-alkylated by-products.

Abstract: An improved process for sulfenylating carbofuran in the presence of a solvent and acid acceptor with a disubstituted aminosulfenyl halide, in which the reaction is conducted in the presence of a catalytic amount of a complex of a lower alkylamine and sulfur dioxide, is disclosed and exemplified.

Abstract: A method is disclosed for removing methyl isocyanate from gaseous effluent streams by contacting the gaseous effluent stream with activated alumina.

Abstract: An improved process is disclosed for sulfenylating carbamates in the presence of a solvent and acid acceptor, in which the reaction between a carbamate and a sulfenyl halide is conducted in the presence of a catalytic amount of a complex of a lower alkylamine and sulfur dioxide. Several methods for preparing and utilizing the complex in the reaction are disclosed and exemplified.

Abstract: Phosphonitrilic chloride polymers are continuously esterified in a process wherein a solution of phosphonitrilic chloride polymer in an organic solvent is concurrently fed into a reactor with an alkanol solution of an alkali metal alkoxide, and the product phosphonitrilic chloride ester is continuously withdrawn and separated.

Abstract: A process is disclosed for the preparation of the herbicide ethyl &agr;-2-dichloro-5-[4-(difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-1H-1,2,4-triazol-1-yl]-4-fluorobenzenepropionate by the simultaneous diazotization of 4-difluoromethyl-4,5-dihydro-3-methyl-5-oxo-1-(5-amino-2-fluoro-4-chloro-phenyl)-1H-1,2,4-triazole (the Amine) and arylation of ethyl acrylate with the diazotized Amine. In the process the following reagents are added in sequence and, under specified conditions, to a cooled, stirred solution of the Amine in acetone: cuprous chloride, hydrochloric acid, ethyl acrylate, and sodium nitrite.