CS201716B1 - Process for the isolation of anhydrous non-aromatic aminoxides - Google Patents

Description

The invention relates to a process for the isolation of anhydrous non-aromatic amine oxides of the general formula

I ^{* 1}

X-W-R

I, wherein ^two of the R p R ₂ znaří aliphatic chain of carbon number 1 to 18. The meaning of the substituents may be the same or grills. X denotes the aliphatic chain and the number of carbon atoms 1 to 18 or (CH ₂ ) _n N (O) R ₂ R ₂ , where n 2 2 to 10 and R *. R ₂ has the same meaning as higher

The non-aromatic amine oxides that are currently manufactured industrially are prepared as variously concentrated aqueous solutions (20 to 50%), which are closely related to their method of preparation.

It is then difficult to isolate the pure, anhydrous active substance which is necessary to obtain for some purposes (determination of physical contacts, physicochemical properties, analytical purposes, etc.) from these solutions (due to the excellent surface-active properties of the amine oxides). This disadvantage - the difficult isolation of the amine oxide from the aqueous solution - is overcome by the process according to the invention, whereby anhydrous amine oxide can be isolated from the aqueous solutions by azeotropic distillation with dry benzene, dry benzene / dry ethanol (1: 1) or dry toluene.

This isolation method has also proved to be useful for those amine oxides which are divine methods

201 716

201 716 did not get rid of water and even those in which even drying in a vacuum desiccator above Ρ Ο Ο at a pressure of 13 Pa, drying over ^P 4 ° 10 at 100 ° C and a pressure of 1.8 kPa did not succeed.

To illustrate this novel method for the isolation of anhydrous non-aromatic amine oxides, the following examples are generally valid for each of the above classes of compounds.

Example 1

The reaction mixture, which after oxidation contains 46 g of R-benzyl-N-dodecylmethylamine-N-oxide, 30 ml of isopropyl alcohol and about 50 g of water, after distilling off the solvent and water at 50 ° C and 1.6 kPa, gives the product formo oil / the same is stated in the literature /. The presence of water in the product was confirmed by okremδ-spectroscopy and bi-NMR spectroscopy.

However, if, after distillation of the solvent, dry benzene is added to the reaction mixture after distillation, it is distilled off at 50 ° C and 1.6 kPa pressure (this procedure is repeated 5 times with 50 ml dry benzene) to give an anhydrous product of m.p. 53-54.5 ° C; analysis (calculated / found X): OT 8.63 / 78.71; H = ll, 55 / 11,55; N = 4.58 / 4.43. No bands characteristic of the presence of water were observed in the infrared spectra, nor were the signals corresponding to the hydrogen at moleclile water observed in the 1 H-NMR spectra.

Example 2

The procedure is similar to that of Example 1, but N, N'-bis (butylmethyl) -1,6-hexanedlamine-N, N'-dioxide, which was obtained as a colorless oil after evaporation of the solvents, was worked up. To dry and remove water, a 1: 1 solution of dry benzene and dry ethanol (5x50 ml) was used, and a solid product was obtained in the form of dihydrate, m.p. 80-102 ° C; Elemental Analysis (calculated / found X): 059.22 / 59.32; 11 = 12.42 / 12.52; N = 8.63 / 8.54.

Example 3

The procedure is similar to Example 1, but N-hexadecyl-N, N7N'-trimethyl-1,6-hexanediamine-N, N'-dioxide, which was obtained as a colorless oil after evaporation of the solvents, was dried and removed water was used dry toluene (5x50 mL) to give a solid product as a monohydrate with mp 137-138 ° C; Elemental Analysis (calculated / found X): 069.39 / 68.28; 11 = 13.04 / 13.26; N = 6.47 / 6.34.

Example 4 ....

The initial procedure is similar to Example 1, but N, N'-bisdiethyl-1,2-ethanediamine-N, N'-dioxide, which was obtained as a colorless oil after evaporation of the solvents, was worked up. Dry benzene (5x50 mL) was used to dry and remove water to give a solid product as Jetrahydrate, m.p. 106 [deg.] C .; Elemental Analysis (calculated / found X): 043.46 / 43.31; H = ll, 67 / 11,49; N = 10.14 / 10.20.

Claims (1)

3 201 716 PRESENTING A method of isolating anhydrous non-aromatic amine oxides of the general formula (I) X - N - R 10 where Rp Rg is known to have an aliphatic chain having carbon numbers of 1 to 18, the meaning of R 2 R 2 m is equal to or different and X is an aliphatic chain of 8 by the number of carbon atoms 1 to 18 or (CHg 2 O 2 R 4 R g where n is 2 to 10 and R p R g are the same as above, characterized in that they are azeotroped with dry benzene or a mixture of dry benzene and ethanol, or dry toluene at 50 ° C and 1.6 kPa.