Abstract: This invention provides a process for optimizing the yield of a 1-(2,4-dichlorophenyl)-4,5-dihydro-1H-1,2,4-triazol-5-one by the chlorination in two steps of a 4,5-dihydro-1-phenyl-1H-1,2,4-triazol-5-one. The critical first step is the selective chlorination of the phenyl ring in the 4-position by addition of chlorine to a solution of the 4,5-dihydro-1-phenyl-1H-1,2,4-triazol-5-one in N,N-dimethylformamide. Chlorination of the product of the first step in acetic acid/water yields the 1-(2,4-dichlorophenyl)-4,5-dihydro-1H-1,2,4-triazol-5-one in high yield.

Abstract: A process for the production of an aryl triazolinones of the formula ##STR1## wherein R is lower alkyl and:X.sub.n is 2,4-dichloro-5-methylsulfonylamino; 2-chloro-5-methylsulfonylamino; 4-chloro-5-methylsulfonylamino; 3-methylsulfonylamino; 4-chloro; 2-chloro; 3-nitro; 4-chloro-3-nitro; 2-chloro-5-nitro; 2,4-dichloro-5-nitro; 2-fluoro; 2-4-chloro; 2,4-dichloro; 4-alkoxy; or 4-alkoxy-2-fluoro;which comprises treating, in a tert-butanol medium, an aryl hydrazine of the formula ##STR2## sequentially with (i) a C.sub.1 -C.sub.3 aldehyde, (ii) a cyanate and weak organic acid, and (iii) a hypohalous acid, a salt thereof, or a halogen.

Abstract: An improved process for the difluoromethylation of a 1-phenyl-1H-1,2,4-triazol-5-one at the 4-position of the triazole ring with chlorodifluoromethane significantly reduces the amount of base required for the process, thereby reducing the environmental impact of the process by reducing the amount of by-product salts in the waste stream. The improvement comprises reacting the triazolinone with potassium carbonate in a solvent such as dimethylformamide, at a carbonate to triazolinone ratio in the range of about 0.55 to 1.0; reducing the water content of the reaction mixture to below about 2400 ppm by distillation; heating the reaction mixture in a sealed autoclave to 110.degree. to 180.degree. C., adding a 10 to 15 percent molar excess of chlorodifluoromethane, heating the reaction mixture at a temperature of 140.degree. to 210.degree. C. for 5 to 60 minutes, and recovering the difluoromethylated triazolinone.

Abstract: A process for the production of aryl triazolinones of the formula ##STR1## wherein R is lower alkyl;X is independently halogen, lower alkyl, nitro, hydroxy, NHSO.sub.2 R', --N(SO.sub.2 R').sub.2, --N(R'(SO.sub.2 R' where R' is lower alkyl, and n is an integer from 0 to 3;which comprises treating, in a tert-butanol medium, an aryl hydrazine of the formula ##STR2## sequentially with (i) a C.sub.1 -C.sub.3 aldehyde, (ii) a cyanate and weak organic acid, and (iii) a hypochlorite, a salt thereof, or a halogen.

Abstract: Process for the nitration of a compound of formula I below with nitric acid in sulfuric acid, according to the following general equation: ##STR1## where X is a Cl or F and R is haloalkyl, for example CHF.sub.2 or CF.sub.2 CHF.sub.2, in which the improvement comprises carrying out said reaction in fuming sulfuric acid.

Abstract: An alkali metal cyanate is prepared by heating a heterogeneous mixture of urea and an alkali metal carbonate in a solvent which selectively dissolves urea, but not the alkali metal carbonate.

Abstract: 3-Phenoxybenzyl 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate is prepared in greater than 90% yield by alcoholysis of lower alkyl 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylates with 3-phenoxybenzyl alcohol. A lower alkyl alcohol, e.g., methanol or ethanol, is generated as a by-product.The process is conducted under reflux at a temperature of at least 100.degree. C. in an inert solvent between approximately stoichiometric amounts of the reactants. The solvent is selected to form an azeotropic mixture with, or boil at a higher temperature than, the lower alkyl alcohol by-product, and the by-product is removed from the mixture by distillation as it is produced. If lower alkyl is methyl or ethyl, n-octane, benzene, toluene, xylene, or mesitylene may be employed, for example.The process is promoted by lower alkyl titanium alkoxide catalysts.