Hoechst Aktiengesellschaft

Karlheinz Miltenberger

Manfred Schmidt

Walter Freyer

Karl Petz

In the esterification of aliphatic C.sub.2 -C.sub.6 -carboxylic acids with aliphatic C.sub.1 -C.sub.4 -alcohols, the ester formed is removed by azeotropic distillation together with the water of reaction. After the water of reaction has been separated in a separating condenser, the ester phase is freed, by washing with water, from acid carried over, and water and alcohol are then removed by distilling off a small fraction of the ester. In this way no salt-containing effluents are produced. The ester is obtained in a very good yield, free from acid and alcohol.

Process for the continuous preparation of esters of lower aliphatic

Process for the reaction of a low-molecular hydroxyl compound with a

In the conversion of trichloroethene and tetrachloroethene into dichloroacetyl chloride (DAC) or trichloroacetyl chloride (TAC) by means of oxygen, the reaction mixture is passed several times as a thin film through the reaction zone. The reaction time for achieving a certain conversion is in this way reduced. In the preparation of DAC, a constant content of acid chloride is established in the reaction mixture by removing some of the mixture and working this up by distillation, while the circulating reaction mixture is simultaneously topped up with fresh trichloroethene.

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Gersthofen, Germany

Karlheinz Miltenberger