The Dow Chemical Company

Dowelanco

Jon A Orvik

Thomas J Dietsche

Dawn L Shiang

Douglas L Pearson

Marc E Halpern

Gary A Roth

Sudarshan K Malhotra

Andrew S Kende

Richard C Krauss

Norman R Pearson

Timothy J Adaway

James William Ringer

Larry D Kershner

Anthony P Haag

Alexander P Fung

Jimmy J Tai

Terry L Wright

Edwin C Steiner

Michael Allen Gonzalez

Michael A DesJardin

Jim Love

J Brian Barron

Anne P Wallin

Carmen A Scott

Thomas A Olmstead

Kay K Kim

Ron B Leng

Sudarhshan K Malhotra

5-Alkoxy-1,2,4-triazolo[4,3-c]pyrimidine-3(2H)-thione compounds, such as 5-ethoxy-8-fluoro-1,2,4-triazolo[4,3-c]pyrimidine-3(2H)-thione, were prepared by cyclization of 2-alkoxy-4-hydrazinopyrimidine compounds, such as 2-ethoxy-5-fluoro-4-hydrazinopyrimidine, with carbon disulfide and hydrogen peroxide. The reaction can be carried out in the presence of a trialkylamine, such as triethylamine, in which case a trialkylammonium salt is obtained. The products are useful intermediates in the preparation of 5-alkoxy[1,2,4]triazolo[1,5-c]-pyrimidine-2-sulfonamide herbicides.

2-alkoxy-4-hydrazinopyrimidine compounds and their use in the

A salt of 2-ethoxy-4,6-dihydroxypyrimidine (DHEP) is prepared by contacting a salt of O-ethylisourea with dimethyl malonate in the presence of a methoxide base to form the salt of DHEP. The salt of DHEP can optionally be protonated with an acid to form neutral DHEP. The reaction is typically conducted in a methanol solvent at a temperature less than about 30.degree. C. Typically, the monosodium salt of DHEP is prepared by contacting O-ethylisourea hydrochloride with dimethyl malonate in the presence of sodium methoxide and methanol solvent.

Process for the preparation of 2-ethoxy-4,6-dihydroxypyrimidine

2-Chlorosulfonyl-5-alkoxy[1,2,4]triazolo-[1,5-c]pyrimidine compounds, such as 2-chlorosulfonyl-5-ethoxy-7-fluoro[1,2,4]triazolo[1,5-c]pyrimidine, that are useful for the preparation of 5-alkoxy[1,2,4]triazolo [1,5-c]pyrimidine-2-sulfonamide herbicides, were prepared in an improved manner from 5-alkoxy[1,2,4]triazolo [1,5-c]pyrimidine-2(3H)-thione compounds, such as 5-ethoxy-7-fluoro[1,2,4]triazolo[1,5-c]pyrimidine-2(3H)-thione, by oxidation with hydrogen peroxide to obtain novel 2,2'-dithiobis(5-alkoxy[1,2,4]triazolo[1,5-c]pyrimidine) compounds, such as 2,2'-dithiobis (5-ethoxy-7-fluoro[1,2,4]triazolo[1,5-c]pyrimidine), and subsequent chloroxidation of these intermediate compounds.

5-alkoxy[1,2,4]triazolo[1,5-c]pyrimidine-2(3H)--thione compounds and

5-Alkoxy[1,2,4]triazolo[1,5-c]pyrimidine-2 (3H)-thione compounds, such as 5-ethoxy-8-fluoro[1,2,4]triazolo[1,5-c]pyrimidine-2(3H)-thione, were prepared by treatment of a 5-alkoxy-1,2,4-triazolo-[4,3-c]pyrimidine-3(2H)-thione compound, such as 5-ethoxy-8-fluoro-1,2,4-triazolo[4,3-c]pyrimidine-3(2H)-thione, with an alkali metal alkoxide in an alcohol solvent selected so that the 5-alkoxy group, the alkoxide, and the alcohol all have the same alkyl group. The trialkylammonium salts of the 5-alkoxy-1,2,4-triazolo [4,3-c]pyrimidine-3(2H)-thione compounds were converted to 3-hydrocarbylthio-5-alkoxy-1,2,4-triazolo-[4,3-c]pyrimidine compounds by reaction with a hydrocarbyl halide, such as benzyl chloride. The products are useful intermediates in the preparation of 5-alkoxy[1,2,4]triazolo[1,5-c]pyrimidine-2-sulfonamide herbicides.

2-Alkoxy-4-hydroazinopyrimidine compounds and their use in the

5-Alkoxy-1,2,4-triazolo[4,3-c]pyrimidine-3(2H)-thione compounds, such as 5-ethoxy-8-fluoro-1,2,4-triazolo[4,3-c]pyrimidine-3(2H)-thione, were prepared by cyclization of 2-alkoxy-4-hydrazinopyrimidine compounds, such as 2-ethoxy-5-fluoro-4-hydrazinopyrimidine, with carbon disulfide and hydrogen peroxide. The reaction can be carried out in the presence of a trialkylamine, such as triethylamine, in which case a trialkylammonium salt is obtained. The products are useful intermediates in the preparation of 5-alkoxy[1,2,4]triazolo[1,5-c]pyrimidine-2-sulfonamide herbicides.

2-alkoxy-4-hydrazinopyrimidine compounds

Anthranilic acids substituted in the 3- and/or 5-position are valuable intermediates for the production of agricultural chemicals. These substituted anthranilic acids can be obtained in good yield without undesirable isomeric byproducts by the oxidative ring-opening of dihydroquinolin-4-ones or quinolin-2,4-diones with t-butyl hydroperoxide in the presence of a base.

Process for the preparation of 3- and/or 5-substituted anthranilic acids

2-Hydrocarbyl-3,6-dichloropyridines are prepared from dichloromethyl hydrocarbyl ketones and acrylonitrile in a two-step process involving an addition reaction under basic conditions to form intermediate 1,1-dichloro-3-cyanopropyl hydrocarbyl ketones and a subsequent cyclization reaction in the presence of hydrogen chloride. Thus, 3,6-dichloro-2-methylpyridine is prepared from 1,1-dichloro-2-propanone and acrylonitrile by the formation and further reaction of 4,4-dichloro-5-oxo-hexanenitrile. The intermediates and products are novel compounds useful in the preparation of herbicides and nitrification inhibitors.

2-hydrocarbyl-3,6-dichloropyridines and their preparation

2-hydrocarbyl-3,6-dichloropyridine compounds

A method for preparing substituted phenoxyphenols which are useful in the preparation of herbicidal (phenoxyphenoxy)propionates is disclosed. The process involves the oxidation of substituted phenoxyphenones to the corresponding phenoxyphenyl esters and their conversion to the desired phenoxyphenol. Novel intermediates for the process are similarly disclosed.

Phenoxyphenoxypropionates, intermediates thereof and methods of

5-Methyl-N-(aryl)-1,2,4-triazolo[1,5-a]-pyrimidine-2-sulfonamides are prepared by the cyclization of N -(3-(((aryl)amino)sulfonyl)-1H-1,2,4-triazol-5-yl)amines with 4-methoxy-3-butene-2-one or its synthetic equivalents in the presence of an aqueous base. By controlling the pH of the condensation between 8.5 and 10.5, by-product formation can be substantially reduced.

Aqueous process for the preparation of

Novel methods for preparing 2-cyano-6-chloropyridines are disclosed. The compounds are useful as intermediates in preparing other intermediates or as intermediates directly used in making pesticides, especially herbicides.

Preparation of 2-cyano-6-chloropyridine compounds

2- and 4-(Dichloromethyl)pyridines containing electron withdrawing substituents on the ring are prepared by the reaction of the corresponding 2- or 4-halopyridines with excess chloroform in the presence of a strong base in a medium containing a dipolar aprotic solvent or a phase transfer catalyst. 3-Chloro-5-(trifluoromethyl)-2-(dichloromethyl)pyridine, for example, is prepared by the reaction of 2,3-dichloro-5-(trifluoromethyl)pyridine with chloroform in the presence of sodium hydroxide and N-methylpyrrolidone. Substituted 2-(dichloromethyl)pyridines are useful as agricultural pesticides and as intermediates for the preparation of agricultural pesticides.

Preparation of substituted (dichloromethyl)pyridines

Novel 2,3-bis((poly)chloromethyl)pyridines and 3,6-dichloro--2-(polychloromethyl)pyridines were obtained by vapor phase chlorination of 2,3-lutidine. Chlorination at about 350.degree. C. using a 14.4 sec. residence time and a chlorine to 2,3-lutidine mole ratio of about 6.8, for example, produced 2-(chloromethyl)-3-(dichloromethyl) pyridine, 3-(chloromethyl)-2-(dichloromethyl)pyridine, 2,3-bis(dichloromethyl)pyridine, 6-chloro-2,3-bis(dichloromethyl)pyridine, 3-(dichloromethyl)-2-(trichloromethyl)pyridine, 6-chloro-3-(dichloromethyl-2-(trichloromethyl)pyridine, 6-chloro-2-(dichloromethyl)-3-(trichloromethyl)pyridine, and 3,6-dichloro-2-(trichloromethyl)pyridine. The compounds are useful as starting materials for herbicides and pharmaceutical agents.

2,3-bis-(poly)(chloromethyl)pyridines

Polychloropyridines containing chlorine substituents in the 2, 3, and 6 positions and, optionally, in the 4 and 5 positions, are prepared from polychloro-2,3-lutidines containing at least one chlorine substituent in each methyl group and, optionally, a chlorine substituent in the 6 position by liquid phase chlorination. Lewis acid metal halide catalysts are, optionally, employed. 2,3,5,6-Tetrachloropyridine is, accordingly, prepared by chlorination at about 200.degree. to about 260.degree. C. in the presence of ferric chloride catalyst of a mixture of polychloro-2,3-lutidines obtained by the vapor phase chlorination of 2,3-lutidine.

Polychloropyridine production from polychloro-2,3-lutidines

The invention relates to a method for selective halogenation of 6-hydroxy picoline derivatives such as 6-hydroxy picolinic acid and 6-hydroxy picoline. When 6-hydroxy picolinic acid is halogenated by allowing it to stand in an aqueous mineral acid solution for a sufficient period to replace the halo substituent with a hydroxy substituent, and then halogenated, an improved yield of the 3-halo, 6-hydroxy picolinic acid to the 5-halo 6-hydroxy picolinic acid is obtained.

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Midland, MI, United States of America

Jon A Orvik