CS212128B1 - Method for preparation atylated derivatives of 1,3-dioxolane - Google Patents

Description

The present invention relates to a process for preparing alkylated 1,3-dioxolane derivatives by reacting octane oxides with water in the presence of sulfuric acid.

Alkylated derivatives of 1,3-dioxolane are prepared most often by reaction of diols with aldehydes or ketones. Octane-1,2-diol with octan-1-alole gives 2 to 6% yield of 2-heptyl-4-hexyl-1,3-dioxolane in the presence of p-toluenesulfonic acid by boiling in toluene at 110 ° C while removing the reaction water azeotropically up to 66%. (Kolaczinski G. et al., Fette, Seifen, Anstriohmittel 73, 9553-557, 1971).

Another method is based on 2,4,4-trimethylpentane-1,2-diol which gives up to 94% yield of dihydro-4-methyl-4-neopentyl-2-1 ', 3', 3 by boiling in benzene in the presence of mineral acid. '-trimetylbutyldioxolánu. (Graham AR et al., J. Org. Chem., 2,180-2,200 (1953)), it is also suitable to use cold concentrated hydrochloric acid, and boiling with 6 N sulfuric acid also produces 2,4,4- trimethylpentane-1-al. The alkylated 1,3-dioxolane derivative which is based on the ethylhexane skeleton in the literature has not yet been described.

According to the invention, it is possible to prepare alkylated 1,3-dioxolane derivatives of the general formula (I)

CH

CH,

-C-R, (I) wherein R 1 is h-heptyl-, 4- (2,2-dimethylpentyl) -, 3-heptyl-,

R 8 is η-butyl-, neo-pentyl-, n-hexyl-,

R ₃ is hydrogen, methyl, ethyl, by reacting the oxo-oxides of formula II

where R 6 is η-hexyl-, neo-pentyl-, n-butyl-,

R 1 is ethyl, methyl, hydrogen and R 3 ^{and R} 4 is hydrogen; with water in the presence of 0.1 to 12% by weight of sulfuric acid, preferably 1 to 3.0% by weight, in an amount such that the molar ratio of water contained in the acid to octene oxide solution of the formula II is 75 to 100, up to 90 ° C, preferably 80 to 90 ° C, and with vigorous stirring to ensure that the reaction in the kinetic region proceeds to the conversion of the octene oxides of the formula II 98 to 100 t, preferably 100% and to the conversion of the octanedioles 95 to 100%, preferably 100 The reaction product is separated from the aqueous sulfuric acid solution and the alkylated 1,3-dioxolane derivatives of the formula I are distilled off at a pressure of less than 1 kPa. In isolation, the separated aqueous phase of the sulfuric acid solution after addition of the loss of its components can be used carefully.

The reaction is characterized in that it is primarily formed from the octene oxides of the formula II with water corresponding to the diol and, at the same time, isomerization of the corresponding aldehyde, which reacts to the alkylated derivative of 1,3-dioxolane. All three reactions are catalyzed by the sulfuric acid present.

The initially formed diol can be dehydrated to the aldehyde during the reaction and reacted with the excess diol to the alkylated 1,3-dioxolane derivative. Under the reaction conditions, the formation of diglycols formed by the reaction of octene oxide with the corresponding diol is significantly suppressed. The optimum concentration of sulfuric acid in the aqueous solution is in the range of 1.0 to 3.0% by weight, a lower concentration slows down the reaction, a sulfuric acid concentration above 12% by weight significantly increases the proportion of the splits associated with the cleavage of the carbon flight. The optimum temperature is in the range of 80 to 90 ° C.

The volumetric ratio of water contained in the aqueous sulfuric acid to octene oxide solution is 75 to 100 to 1, allowing the reaction to proceed under isothermal conditions. The complete conversion of the inserted octene oxide and, if possible, the diol formed therefrom, simplifies the conditions for the subsequent separation of the products by reaction. The reaction takes place in two liquid, non-intermittent phases, stirring must be intensive enough to ensure the contact of the cutters. After separation of the organic phase, it is necessary to remove entrained sulfuric acid from it, which could decompose the product during its isolation by distillation.

An advantage of the process according to the invention is the preparation of alkylated derivatives of 1,3-dioxoleneths from the starting product of the octene oxides of the general formula II is a simple procedure and the use of mild conditions. The invention is applicable to the following otanoxides of formula II: octene-1,2-oxide, 2-ethylhexene-1,2-oxide and 2,4,4-trimethylpentane-1,2-oxide as well as other structural analogs. The reuse of a separate aqueous sulfuric acid solution after adding its components to the original values will increase the yield of the product.

Example 1

In a 250 ml flask equipped with a reflux condenser, thermometer and stirrer, the aqueous sulfuric acid solution was heated to the desired temperature with stirring. Add 0.1 mole of octene oxide and heat and stir for a specified period of time, after which the organic phase is separated and analyzed by gas chromatography. The product is separated by de-distillation e and a pressure of less than 1 kPa. The conditions of the individual experiments as well as product extracts are given in Table no. First

table P. 1 Preparation of 2-heptyl-4-hexyl-1,3-dioxolane from octene-1,2-oxide. Number Conditions experiment temperature (° C) Conc. H 2 SO 4 Molar ratio of water; in the aqueous phase of octane-1,2-oxide (56 wt.) Time (Min) 1 2 90 90 12,0 75 3,0 75 120 120 CONTRACTING TABLE NO. 1

Number Composition (56 wt.) Of the experiment Octane-1,2-oxide Octane-1,2-diol Diglycols * 2-Heptyl-4-hexyl-1,3-dioxolane

0 37.8 0 38.8

0 75,9 1,2 18,1 diglycols * = summary designation for the three isomeric diglycols produced by the reaction of octane-1,2-oxide and octane-1,2-diol.

Example 2

The procedure was as in Example 1 except that 2 (1-ethylpentyl) -4-ethyl-4-butyl-1,3-dioxolane was prepared from 2-ethylhexane-1,2-oxide.

Table 8. 2 Conditions and preparation of 2 (1-ethylpentyl) -4-ethyl-4-butyl-1,3-dioxolane from 2-ethylhexane-1,2-oxide.

Number experiment Conditions. temperature (C> Conc. HgSO ^ in aqueous phase (56 wt.) Molar ratio of water: 2-ethyl-1,2-dioxide time (Min) 1 90 1.0 100 180 2 90 3.0 100 180 3 90 10.0 100 30

Pokreéovanie table 1. 2

Number composition by weight.) experiment 2-Ethylhexane-2-Ethylhexane-Alkenolj -1,2-oxide -1-al C ₈ ⁺ hexane-1,2- ^- Diglycols ** ('S-T-IphyP' pentyl) -4-

-diol-ethyl-4-butyl-1,3-dloxolane

1 0 5.6 10.6 11.4 0 59.6 2 0 14.8 4 * 4 0 0.6 66.6 3 0 13.0 6.6 0 6.6 60.5

alkenols Cg ⁺ = collective designation for 2-butyl-trans-but-2-en-1-ol-2-butyl-cis-but-2-en-1-ol, 2-ethyl-trans-hex-2-ene 1-ol and 2-ethyl-eis-hex-2-en-1-ol.

diglycols ⁺⁺ = collective designation for the three isomeric diglycols, formed by the reaction of 2-ethylhexane xane-1,2-oxide with 2-ethylhexane-1,2-diol.

Example 3

The procedure was as in Example 1 except that 2-ethylhexane-1,2-oxide was added to the reaction. The results of sd shown in Table no. 3 ·

Table no. 3 Conditions and Preparations of 2- (1,3,3-trimethylbutyl) -4-methyl-4- (2,2'-dimethylpropyl) -1,3-dioxolane from 2-ethylhexane-1,2-oxide.

number Podmienkv ' experiment temperature (° C) Conc. HgSO4 in aqueous phase (wt.%) Molar water ratio: 2,4,4-trimethylpentane-1,2-dioxide Time (Min) 1 70 0.1 100 8 2 90 - 0,1 100 8 3 90 0.1 100 90 4 40 1.0 100 5 5 90 1.0 100 120 6 90 3.0 100 3.5 7 10 10.0 100 8 8 10 10.0 100 60 9 90 10.0 100 2 0 90 10.0 100 15

Table no. 3

experiment 2,4,4-Trimethylpentane-1,2-dioxide 2,4,4-Tri-Alkenols 2,4,4-Trimethylpentane-1,2-diol 2 (1,3,3-tri- methyl-butyl) - 4-methyl-4- - (2,2-dimethyl- propyl) - ,, 3- dioxolane methylpentan-1-al ^C 8 (wt.%) 1 0.4 24.4 12.0 58.4 0 2 0.3 24.8 12.3 54.3 2.8 3 0 26.1 11.4 37.1 13.6 4 1.9 25.1 10.6 62.7 3.7 5 0 35.0 7.8 1.2 47.9 6 0 37.9 13.4 21.8 22.6 7 0.7 24.0 9.8 50.8 8.7 8 0 21.1 8.2 49.3 15.8 9 0.6 50.8 10.7 13.3 19.4 10 1.2 55.2 4.9 4.9 30.0

alkenols 0θ ⁺ = collective designation for 2,4,4-trimethylpent-1-en-3-ol and 2,4,4-trimethylpent-2-en-3-ol.

The process described in the invention may be used to prepare alkylated 1,3-dioxolane derivatives.

Claims (2)

OBJECT OF THE INVENTION 1. A process for the preparation of alkylated 1,3-dioxolane derivatives of the general formula I I ¹ CH R (I) wherein R 1 is η-butyl-, 4- (2,2-dimethylpentyl) -, 3-heptyl-, R 1 is η-butyl-, neo-pentyl-, n-hexyl-, R 1 is hydrogen, methyl, ethyl, by reaction of octanoxides of formula II (II) wherein R (is η-butyl, neo-pentyl, n-hexyl, R1 is hydrogen, methyl, ethyl, with water in the presence of sulfuric acid, characterized in that the octanoxides of the formula II are treated with an aqueous solution of sulfuric acid at a concentration of 0.1 to 12.0% by weight, preferably at a concentration of 1.0 up to 3.0% by weight, in an amount such that the molar ratio of water contained in the sulfuric acid solution to the octanoxides of the formula II is equal to 75 to 100, at a temperature of 10 to 90 ° C, preferably 80 to 90 ° C with vigorous stirring the reaction in the kinetic region, to a conversion of the octanoxides of the formula II of 98 to 100%, preferably a conversion of 100% and to the conversion of the corresponding octadioles of 95 to 100%, preferably to 100%. The 1,3-dioxolane of formula I is distilled off at a pressure of less than 1 kPa. 2. The process of claim 1 wherein the octanoxides of formula (II) are treated in a previous reaction with a separate aqueous phase of the sulfuric acid solution after the loss of its components has been completed.