The Dow Chemical Company

Lorraine M Kroposki

Masao Yoshimine

Harold H Freedman

Stanley D McGregor

Quaternary ammonium salts and sterically unhindered, nucleophilic, tertiary amines are novel cocatalysts which are used in the process of reacting an alkali metal phenate, pyridinate or pyrimidinate with an O,O-dialkylphosphorochloridothioate or O-alkyl phenylphosphonochloridothioate to produce the corresponding phosphorothioates and phenylphosphonothioates. The process is conducted under alkaline conditions in a liquid reaction medium.

Process for preparing phosphorothioates and phenylphosphonothioates

Mixtures of (1) a quaternary ammonium salt(s) and (2) a diazole are novel catalysts in the process of reacting an alkali metal phenate, pyridinate or pyrimidinate with an O,O-dialkyl phosphorochloridothioate or O-alkyl phenylphosphonochloridothioate to produce the corresponding title compounds. The process is conducted under alkaline conditions in a liquid reaction medium. As an example, O,O-diethyl O-(3,5,6-trichloro-2-pyridyl)phosphorothioate is prepared in excellent yields and purity by reacting sodium 3,5,6-trichloro-2-pyridinate with O,O-diethyl phosphorochloridothioate in a stirred methylene chloride-water reaction medium in the presence of a catalytic amount of benzyltriethylammonium chloride and 1-methylimidazole.

Mixtures of (1) a quaternary ammonium salt(s) and (2) 1,4-diazabicyclo[2.2.2]octane are novel catalysts in the process of reacting an alkali metal phenate, pyridinate or pyrimidinate with an O,O-dialkyl phosphorochloridothioate or O-alkyl phenylphosphonochloridothioate to produce the corresponding phosphorothioates and phenylphosphonothioates. The process is conducted under alkaline conditions in a liquid reaction medium. As an example, O,O-diethyl O-(3,5,6-trichloro-2-pyridyl)phosphorothioate is prepared in excellent yields and purity by reacting sodium 3,5,6-trichloropyridinate with O,O-diethyl phosphorochloridothioate in a stirred methylene chloride-water reaction medium in the presence of a catalytic amount of benzyltriethylammonium chloride and 1,4-diazabicyclo[2.2.2]octane.

Mixtures of (1) a quaternary ammonium salt(s) and (2) 1,4-diazabicyclo[2.2.2]octane are novel catalysts in the process of reacting an alkali metal phenate, pyridinate or pyrimidiate with an O,O-dialkyl phosphorochloridothioate or O-alkyl phenylphosphonochloridothioate to produce the corresponding phosphorothioates and phenylphosphonothioates. The process is conducted under alkaline conditions in a liquid reaction medium. As an example, O,O-diethyl 0-(3,5,6-trichloro-2-pyridyl)phosphorothioate is prepared in excellent yields and purity by reacting sodium 3,5,6-trichloropyridinate with O,O-diethyl phosphorochloridothioate in a stirred methylene chloride-water reaction medium in the presence of a catalytic amount of benzyltriethylammonium chloride and 1,4-diazabicyclo[2.2.2]octane.

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Walnut Creek, CA, United States of America

Lorraine M Kroposki