Bayer Aktiengesellschaft

Deutsche Gold- Und Silber-scheideanstalt Vormals Roessler

Degussa Aktiengesellschaft

Bayeraktiengesellschaft

Gerd Siekmann

Willi Hofen

Rolf Wirthwein

Helmut Waldmann

Gerd Schreyer

Herbert Klenk

Wulf Schwerdtel

Gunter Prescher

Hermann Seifert

Martin Littmann

Ralf Goedecke

Paul Fiedler

Gunter Wolf

Achim Noak

Manfred Lenthe

A process for making the known fungicide intermediate 2-(4-chlorophenyl ethyl)-2-tert.-butyloxirane of the formula ##STR1## comprising (a) mixing a solution of trimethylsulphonium bromide of the formula

Process for the preparation of

In a process for the continuous preparation of pure organic solutions of percarboxylic acids having 2 to 5 carbon atoms, by

Process for the preparation of percarboxylic acid solutions

The invention relates to a process for the production of .epsilon.-caprolactone having a purity of 99.9% and increased color and storage stability which comprises feeding .epsilon.-caprolactone, which has been made by reacting cyclohexanone with a solution of a percarboxylic acid, into a first distillation unit, operating at 0.1 to 500 mbars and drawing off as the top product a mixture consisting of .epsilon.-caprolactone and lower-boiling impurities, feeding the bottom product of said first distillation unit into a second distillation unit, operating at 0.1 to 500 mbars and then drawing off the pure .epsilon.-caprolactone as the top product. The .epsilon.-caprolactone is useful as an intermediate for the production of known useful compounds such as polyesterols which are subsequently converted to polyurethanes.

Process for the manufacture of very pure .epsilon.-caprolactone

Process for continuous production of substantially anhydrous solutions of percarboxylic acid in solvent. Aqueous hydrogen peroxide is first reacted with the corresponding carboxylic acid in the presence of acid catalyst to form percarboxylic acid and water (1). The percarboxylic acid is extracted with solvent (5), to provide a solvent phase containing the percarboxylic acid (11) and an aqueous raffinate (7). The solvent phase is subjected to distillation (12) to provide the anhydrous solution (13). In this distillation (12) the hydrogen peroxide remaining in the solvent phase produced in the extraction (5), is distilled off together with water and some solvent, and the hydrogen peroxide is recovered as an aqueous phase and recycled (14). The aqueous raffinate, which contains hydrogen peroxide, is distilled to remove water (8) and the resulting concentrate is recycled (2) for use in the reaction (1).

A process for the continuous preparation of organic solutions of percarboxylic acids by reaction of an aqueous solution of hydrogen peroxide with the corresponding carboxylic acid in the presence of an acid, water-soluble catalyst which boils above 160.degree. C., extraction of the percarboxylic acid from the resulting reaction mixture using an organic solvent which is immiscible with water, reconcentration of the raffinate, which essentially contains hydrogen peroxide and the acid catalyst, by distilling off water in a distillation column and recycle of the raffinate, concentrated in this way, into the reaction with the carboxylic acid. The raffinate is divided into two partial streams in a ratio of 1 to 25:1. The raffinate is fed to a distillation column which is operated under reduced pressure and which has at least two take-off weirs as tray inserts, the first take-off weir being at least two theoretical plates above the sump phase, the second take-off weir being arranged at least two theoretical plates above the first take-off weir and the section of column between the second take-off weir and the top of the column having at least two theoretical plates. The larger partial stream of the raffinate is passed into the column below the first take-off weir and the smaller partial stream is passed into the column below the second take-off weir. Water is removed at the top of the distillation column. A first side stream, which essentially contains the hydrogen peroxide from the small partial stream of the raffinate from the extraction, is withdrawn from the second take-off weir and is a 2 to 40% strength by weight aqueous solution of hydrogen peroxide, which is optionally fed, together with the larger partial stream of the raffinate from the extraction, into the column below the first take-off weir. A second side stream is withdrawn from the first take-off weir and is an aqueous solution of the acid catalyst which optionally can be further worked up and re-used. The re-concentrated aqueous solution of hydrogen peroxide and acid catalyst, withdrawn as a sump product from the distillation, is recycled into the reaction with carboxylic acid. A third side stream can be taken from a third take-off weir which is arranged not more than 2 theoretical plates below the first take-off weir.

Process for the preparation of organic solutions of percarboxylic acids

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Cologne, Germany

Gerd Siekmann