CS270154B1 - Preparation of 2- (6-dialkyl-N- (1'-.alpha.) -. - Google Patents

Abstract

The invention relates to a process for the preparation of 2,6-dialkyl-N-(1-ethoxy-2-propylidene) aniline of the general formula I by reacting 2,6-dialkylene of the formula IZ and ethoxy propanoic acid with a 2,6-dialkyl- -eniline » ■•ethoxypropanoate 1 < 1.6 to 4 under a rectification column; with the separation of the reaction water in the azeotropic form and with the isolation of the product by rectification. The invention can be used in the chemical industry.

Description

The present invention relates to a process for the preparation of 2,6-dialkyl-N / 1'-ethoxy-2'-propylidene / aniline by the reaction of 2,6-dialkylaniline and ethoxypropenone.

Schiff bases ·· generally prepare by the reaction of aliphatic or aromatic aroins and aliphatic · !, cycloallphatic ·! or an aromatic carboxylic compound. Many of them are common to doetup compounds (Houben - Weyl i Methodsen der organiechen Chemie, Stieketoffverbindungen II, III, 11/2, etr. 73-89, Georg Thieae Verlag, Stuttgart 1959 /.

Schiff bases prepared from eromethyl amines and aliphatic ketones are not common. aedziproduktaai, eynthesis ea and recover in low yields or are subject to further preaená · / Eaereon w. S. Organie reactone IV, atr. 174 - 255, Oohn Willey, Sone, New York 1949 /. The reaction of · aniline · acetone · led e.g. for the aldolysis of acetone to azesyl oxide and further to 2,2,4-triethyldihydroquinoline, preferably before the formation of isopropylidene aniline (Riddaliav G, Thurn A, Ber. 65. 1511/1932/7 ·

The reaction of · 2,6-dialkyleniline and aetoxypropanone in an organic solvent led to the formation of equilibria for ·· !, which ·· stops the conversion to 25-40%! in dependence on the reaction data. It is known that the reaction equilibrium in the formation of Schlff's base can be triggered by the formation of a product of the decontamination of reaction water from proetradium in a ferric azeotropic plant and an inert solvent such as banzen, toluene, xylene, cyclohexane and other disadvantages. water and inert! the solvent ea does not achieve a high conversion of the reaction, but the reaction ea seals the composition of the reaction salt 2-setyl-6-ethylaniline t Schiff base 1: 1, even when aatoxypropanone takes up the reaction in excess ·

It is now possible to prepare 2,6-dialkyl-N- [1'-ethoxy-2'-propylidene] aniline of the general formula I

2 in which R 1 and R 2 denote, independently of one another, alkyl or ethyl by the reaction of the corresponding 2,6-dialkylaniline and ethoxypropenone according to the invention. 1.5 to 4 below the rectification column, separating the reaction water in the form of an azeotropic seed and isolating the product by ratification.

The preparation of 2,6-dalkylalkyl-N- [1'-sotoxy-2'-propylidane] aniline according to the invention gives the product in high yield.

The following examples illustrate but illustrate the praduet of the invention.

Example 1

Again, 15.0 g (2 mmol) of 2-aatyl-6-ethylaniline and 30.0 g of 84.4% (0.29 mol) of aethoxypropanone in ethoxypropanol are heated to reflux under a rectification column of 25 ca. At the head of the column ea takes an azeotrope and t.v. 94 ° C · With the distillation of water from the reaction zone, the temperature at the top of the column rises gradually until finally pure aatoxypropanone is distilled at 117 ° C.

Under reduced pressure ea, the residual ethoxypropanone epole and 1-ethoxy-2-propanol are removed, and finally the product passing at a temperature of 64-67 ° C / 10.6 Pa ·

Yield 20 g (87.7% yield) of 2-ethyl-6-style-N- [1'-ethoxy-2'-propylidene] aniline 2

CS 270 154 Bl liquid of avetloiltsj color.

The yield of the starting 2-ethyl-6-ethylaniline (determined by gas chromatography) is 2.7%. Example 2

Zees 40 (5 g, 0.3 mol) of 2-methyl-6-ethylaniline and 46.6 g (δ, δ δ) of aetoxypropanone with a purity of 97.2% are refluxed with ezeotropic distillation of the reaction water at the top of the rectification column as in Example 1 *. '

Double modification gave 63.0 g of product (84.6% yield) in both 0.4% of 2-ethyl-6-ethylaniline.

Analysis for C ₁₃ H N0 _ug / M 205.29 /

Off / Det. % C 76.05 / 76.33)% H 9.3 / 9, ‘86:% N 6.8 / 6 ^ 71

Example 3

After 20.0 g (0.13 aol) of 2,6-diethylaniline and 55.4 g (0.6 aol) of 65 g of aetoxypropanone, the reaction mixture is reacted as in Example 1. 2,6,6-diethyl-N- [l * - The ethoxy-2'-propylidene / aniline is purified by purification to give the product in 91.7% yield in a purity of 99.1% by weight. in.

109 - 111 ° C / 6.0 Pa.

Analysis for C ₁₄ H ₂₁ NO / M - 219.31 /

Off / Det. % C 76, '66 / 76, 55)% H 9, '65 / 9.34)% N 6.39 / 6.60

Claims (1)

2 CS 270 154 B1 light yellow color. The amount of starting 2-ethyl-6-ethylaniline (determined by gas chromatography) is 2.7%. EXAMPLE 2 Again, 40 [mu] g / 0.1 [mu] l / 2-ethyl-6-ethylaniline and 46.6 g / [mu] L / aol / aetoxypropanone of 97.2% purity were refluxed under azeotropic removal of the reaction water at the rectification column as in Example 1 * By rectification, 53 g of product (84.6% yield) and 0.4% of 2-ethyl-6-ethylaniline are recovered by analysis. discover. % C 76.05 / 76.33)% H 9.3 / 9, ‘86 j% N 6.8 / 6 ^ 71 Example 3? Zaea 20.0 g / 0.13 aol / 2,6-diethylaniline and 55.4 g / 0.06 aol / 65 aetoxypropanone are reacted with the base as in Example 1, 2, 6-diethyl-N- / l # - aethoxy-2 ' -propylidene / aniline and purification by rectification, aa product in 9L, 7% non-99% yield, 1% e.e., 109-111 ° C / 6.0 Pa. Analysis for C ^ ^HgjNO / M 219 219, 31 / Off / Gold. % C 76, '6β / 76.55)% H 9, '65 / 9.34)% N 6.39 / 6.60 FOR THE INVENTION Preparation of 2,6-dialkyl-N- (1 * -aethoxy) -2, -propylidene / aniline of general formula I CK, (1), in CHGOCK2 R212 in which R and R are independently ethyl or ethyl by reaction of 2,6-dialkylaniline of formula II Wherein the reaction is carried out in the presence of aoxide and a 2- (2-6-cyanolanine) aethoxypropanone 1: 1.5 to 4 below the rectification point. column to separate the reaction water in the azeotrope form and isolate the product by rectification.