DE899498C - Process for the preparation of the phosphoric acid tri- (2-ethyl-n-hexyl) ester - Google Patents

Description

Process for the preparation of the phosphoric acid tri- (2-ethyl-n-hexyl) ester It is known to produce neutral phosphoric acid esters of primary aliphatic alcohols, by mixing phosphorus oxychloride, expediently in vapor form, with the excess alcohol reacted, advantageously under reduced pressure; this is the one formed in the reaction Hydrogen chloride is constantly removed from the reaction mass. Another method To prepare the esters mentioned, the phosphorus oxychloride is used mix with an excess of the alcohol and heat the mixture moderately so that the Hydrogen chloride does not escape or only partially escapes. Both procedures lead to the production of phosphoric acid tri- (2-ethyl-n-hexyl) -ester to difficulties, mainly because the yields are unsatisfactory. You can use phosphoric acid tri- (2-ethyl-n-hexyl) ester by the action of phosphorus oxychloride on the sodium compound of 2-ethylhexanol- (z) produce. However, this method is also difficult to use in technology carry out, since the removal of the sodium chloride formed during the reaction does not is simple and, moreover, a very large excess of ethylhexanol can be used got to.

It has now been found that the ester can be obtained in a much simpler way can be obtained in very good yield if you 2-ethylhexanol (r) in submitted Lets phosphorus oxyhalide flow in and by introducing a stream of inert gas the hydrogen halide formed during the reaction from the reaction mixture quickly removed. By removing the hydrogen halide, no reaction is achieved occurs with the supplied ethylhexanol. Inert gases are therefore to be used use that with none of the implementation participants under the applied conditions react, e.g. B. nitrogen, carbon dioxide or oxygen. The temperature at the Implementation can vary within wide limits; it is generally between about o and ioo °; the best yields are obtained at around 20 °. To end the implementation it is advisable to heat the mixture to around 100 ° for some time.

The raw product can be removed from the in free him contained excess ethylhexanol, whereby it is expedient at Presence of some soda to work to reduce acidic components present in small quantities to neutralize. If a product that is as colorless and odorless as possible is desired you can treat the ester with decolorizing agents such as animal charcoal, or treat it subject to steam distillation in vacuo. Example In 300 parts by weight Phosphorus oxychloride is left with stirring for 2 hours at 2o ° 1200 parts by weight 2-Ethylhexanol- (1) flow, with a vigorous stream of nitrogen flowing through the mixture directs. The mixture is stirred for a further 1 hour in a stream of nitrogen and then heated for 1 hour in a vacuum to 100 °. After adding 50 parts by weight of anhydrous soda, the raw product fractionated in a vacuum. First of all, unreacted ethylhexanol goes over, then follows an intermediate run, finally distilled at about 2 mm Hg between 21o and 23o ° of the phosphoric acid tri- (2-ethyl-n-hexyl) ester itself over.

The yield of pure ester is 60 parts by weight. Another 60 parts by weight are contained in the intermediate run and can also be obtained in pure form by repeated fractionation, so that the total yield is 67o parts by weight = 790 /, of theory, based on the phosphorus oxychloride used.

Claims (1)

PATENT CLAIM: Process for the preparation of the phosphoric acid tri- (2-ethyl-n-hexyl) ester, characterized in that 2-ethylhexanol- (1) is poured into phosphorus oxyhalide leaves and by introducing an inert gas stream that formed during the reaction Rapidly removed hydrogen halide from the reaction mixture. Attracted pamphlets Liebigs Annalen der Chemie, Supplement 6 (1868), p.263.