Solvay Sa

Solvay Fluor Und Derivate Gmbh

Uta Claassen

Max Josef Braun

Stefan Palsherm

Alain Lambert

Sara Claessens

Process for preparing a halogenated precursor of an alkenone, which comprises reacting a carboxylic acid halide with a vinyl ether in a liquid reaction medium using an equipment having at least one surface in contact with the liquid reaction medium, wherein said surface consists of a material selected from glass, polytetrafluoroethylene and nickel based metal alloy.

Process for the manufacture of halogenated precursors of alkenones and of alkenones

Process for synthesizing a chemical, in particular an agriculturally or pharmaceutically active compound, including: a first step comprising reacting a carboxylic acid halide with a vinyl ether to prepare a halogenated precursor of an alkenone; a second step comprising eliminating hydrogen halide from such precursor to form an alkenone, preferably by thermolysis under specific conditions; and a third step which uses the formed alkenone as a building block to synthesize the chemical. First step may be done in a liquid reaction medium comprising an alkenone or a halogenated alkenone precursor, or in a liquid reaction medium in turbulent state, specifically by creation of gas bubbles of the carboxylic acid halide herein. Second step may include a flash thermolysis, vacuum thermolysis, thermolysis under stripping with inert gas, and/or a thermolysis at a temperature from &#x3e;90&#xb0; C. to 120&#xb0; C. Third step preferably comprises reacting the alkenone with a nitrogen-containing compound.

Process for chemical synthesis from an alkenone made from a halogenated precursor

A process for preparing a halogenated precursor of an alkenone, which comprises reacting a carboxylic acid halide with a vinyl ether in a liquid reaction medium under turbulent conditions and a process for preparing an alkenone, by eliminating hydrogen halide from said precursor to form the alkenone.

Process for the manufacture of halogenated precursors of alkenones under specific conditions

Process for preparing an alkenone, which comprises the following steps: (a) providing a halogenated precursor of the alkenone; and (b) eliminating the hydrogen halide from said precursor to form the alkenone by a thermolysis treatment selected from the group consisting of flash thermolysis, vacuum thermolysis, and thermolysis under stripping with inert gas.

Process for the manufacture of alkenones

A process for preparing a halogenated precursor of an alkenone, which comprises reacting a carboxylic acid halide with a vinyl ether in a liquid reaction medium comprising an alkenone or a halogenated precursor of the alkenone, and a process for preparing an alkenone, which comprises (a) reacting a carboxylic acid halide with a vinyl ether by introducing vinyl ether into a liquid reaction medium containing carboxylic acid halide to form a halogenated precursor of the alkenone and (b) eliminating hydrogen halide from said precursor to form the alkenone.

Process for the manufacture of halogenated precursors of alkenones in the presence of a solvent

A method of producing a halogen alkenone ether by attaching carboxylic acid halogenides or carboxylic acid anhydrides to a vinyl ether. According to the invention the method is carried out in the presence of an onium salt of a carbonic acid which can be regenerated. The resulting product is obtained in high yields. Alternatively, pyridine which is substituted by one, two or three C1&#x2013;C3 alkyl groups or other onium salts can be used.

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Hohenhameln, Germany

Uta Claassen