Rhone-Poulenc Agrochimie

Philagro

Andre Bernard

Andre Disdier

Michel Royer

Bernard Buathier

A racemic or optically active alkyl 2-chloropropionate is prepared, respectively, from a racemic or optically active alkyl lactate by, in a first step, gradually bringing the alkyl lactate into contact with the thionyl chloride, in the presence of an organic base, while maintaining, in the reaction mixture, an excess of thionyl chloride, relative to the amount of alkyl lactate introduced into this mixture, at a temperature below the decomposition point of the chlorosulphinate of the alkyl lactate, which is formed as an intermediate, and then, in a second step, in heating the reaction mixture resulting from the first step at a temperature which is at least equal to the decomposition point of the chlorosulphinate of the alkyl lactate. The alkyl 2-chloropropionates can be used for the manufacture of the racemic or optically active 2-phenoxypropionic acids.

Process for the preparation of an alkyl 2-chloropropionate by

Aluminum monoethyl-phosphite, useful for the protection of plants against fungal diseases, is manufactured in a continuous manner by first preparing a mixture of phosphite compounds, containing at least 70 mol % of diethyl phosphite, then saponifying and neutralizing such mixture with an inorganic base, at a temperature of 20.degree.-85.degree. C., at a pH of 4.0-8.5, and finally reacting the residual aqueous solution of alkaline metal monoethyl-phosphite, continuously withdrawn from the preceding operation, with an approximately stoichiometric amount of a water-soluble aluminum salt at 70.degree.-95.degree. C. and a pH of 3.0-4.5.

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Villeurbanne, France

Andre Bernard