SU1341174A1 - Method of producing 2-substituted or 2,2-substituted 1,3-propandiols - Google Patents

Description

The invention relates to a process for the preparation of 2-substituted or 2,2-substituted 1,3-propanediols, which can be used as plasticizers, solvents.

The purpose of the invention is to simplify the process.

Example 1 To 82 g of sodium borohydride, mixed with 120 g of carefully crushed and freshly baked (3 hours at 400-500 ° C) anhydrous calcium chloride, 1100 ml of dry tetrahydrofuran are poured, vigorously stirred at 70 ° C for 45 minutes, and then 244 g of dipropylmalonic ester is added at such a rate that the mixture boils evenly. Stirring is continued without heating for another 1 hour and for 20 hours, and then with stirring, most of the tetrahydrofuran (800 ml) is distilled off. 1100 ml of water and 160 ml of concentrated hydrochloric acid (before the acidic reaction on Congo) are added to the residue slowly with stirring. After the dissolution of the residue is complete, the oily layer is separated and the aqueous layer is extracted three times with 300 ml of ethyl ether. The ether extracts are combined with an oily layer, washed with a 10% solution of n chloride and neutral,. dried over sodium sulfate; and distilling off the ether. The residue hardens at room temperature. It is subjected to vacuum distillation, a fraction of 145-155 ° C / 5 mm Hg is taken. which solidifies into colorless crystals with so pl. 54-56 ° C. If the residue remains liquid, a solution of 50 g of potassium hydroxide in 400 ml of ethyl alcohol is added to it, ethyl alcohol is boiled off for 3 hours, the solid residue is dissolved in 150 ml of water, the oily layer is separated. the aqueous layer is washed three times with 75 ml of ethyl ether. The ethereal extracts were combined with an oily layer, washed twice with 150 ml of a complete solution of sodium chloride, dried over anhydrous sodium sulphate, the ether was distilled off and the residue was subjected to vacuum distillation. 120 g of 2,2-dipropyl-1,3-propane diol are obtained (75.5% of the theoretical).

EXAMPLE 2: Outcome of 24.4 g of hexyl malonic ester. The synthesis is carried out analogously to example 1. A fraction of 145-155 C / 5 mm Hg is taken.

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when standing, it solidifies into a waxy mass with m.p. 32-35 C. The yield of the product (2-hexyl-G, 3-propane diol) 12.1 g (75.9% of theoretical).

Example K160g of quickly crushed anhydrous (immediately before synthesis, taken from the sealed ampoule) of aluminum bromide, dry diglyme is carefully added dropwise. The first drops react violently with flashing. When about 10 ml of diglyme is added, the flashing is stopped and the diglyme can be added faster with such a rate that the reaction mixture is moderately smoked. Just over 2.5 hours, 300 mg of diglyme was added with stirring. When all the diglyme has been added, the reaction mixture is gently heated to dissolve the aluminum bromide, allowed to cool to 35 ° C, 120 ml of dry ethyl ether, 244 g of dipropylmalonate ether and another 500 ml of dry ethyl ether are added with stirring. Then, in small portions, 67 g of sodium borohydride are added at such a rate that the reaction mixture boils evenly (for 3 hours, at

 mixing). After continued stirring, the reaction mixture is heated for another 10 hours at low boiling. After cooling to room temperature, the reaction mixture is poured.

5 to a 5 liter porcelain cup and, with stirring, slowly add 15 ml of water, and then 20 ml of diluted (1: 4) hydrochloric acid. When the mixture becomes mushy, hydrochloric acid (1: 1) is added before the acidic reaction to Congo and complete precipitation of the precipitate. The oily layer is separated, the aqueous layer is washed 3 times with 100 ml of ethyl ether. The ether extracts are combined with an oily layer, washed with 10% sodium carbonate solution until alkaline, and then saturated; sodium chloride solution until neutral. With

In this part of the ether layer is transformed into a mushy mass, which separates from the aqueous layer, the ether solution is sucked off from it, and the solid residue is heated with stirring with

55 75 ml of a 15% aqueous solution of sodium hydroxide until the residue is converted into a liquid oily layer which solidifies on cooling. The frozen raw product is sucked off from the alkali,

washed with a saturated solution of sodium chloride, treated with 60 ml of ethyl ether, filter the final solution from the insoluble residue, which is again subjected to heating with alkali. This operation is repeated several times until a small amount (several grams) of the residue is obtained, which does not change upon heating with alkali. The combined ether solutions are dried over anhydrous sodium sulphate, the ether is distilled off and the residue is distilled in vacuo, a fraction of 145-155 ° C / 5 mm Hg is taken, which solidifies to colorless crystals with mp. 54-56 C. The yield of 2,2-diprapst-1,3-propane diol 149.5 g (93.3% of theoretical).

Example 4. To 16, OG of quickly chopped anhydrous (immediately before synthesis taken from the sealed ampoule) of biline julumini, 150 ml of dry monoglyme are poured while stirring and cooling for 10 minutes, then a mixture of 6.7 g of sodium borohydride and 75 ml of monoglyme for 20 minutes and 24.4 g of dipropylmalonic. ether for 1 h. Next, the reaction mixture is heated with stirring at 70 € for 20 h, allowed to cool and slowly with stirring, the reaction mixture is poured into a solution of 10 ml of hydrochloric acid in 30 ml of water. The upper organic layer is separated, and the aqueous layer is washed three times with 30 ml of ethyl ether. The ether solutions are combined with the organic layer, washed with a saturated sodium chloride solution in a neutral reaction, dried over anhydrous sodium sulfate, the ether is distilled off and monoglyme, and the residue is treated as in Example 1. The yield 12.3 g (80.1% of theory).

Example 5: Outcome of 40.4 g of methyl ethyl ether. Synthesis

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is carried out analogously to example 3 with the difference that the aqueous layer is always saturated with sodium chloride. A fraction of 90-98 C / 5 mm Hg is taken, which solidifies into colorless crystals with a mp. 40-41 C. The yield of 2-methyl-2-ethyl-1,3-propane diol 17.3 g (74.5% of theoretical).

0 Approx. Outcome of 54.4 g of octyl malonic ester. The synthesis is carried out according to Example 3. A fraction of 148-158 ° C / 5 mm Hg is taken out, which solidifies to a colorless mass, mp. 5 34-36.С. The yield of 2-octyl-1,3-propanediol is 30.3 g (80.6% of the theoretical). Example 7: Outcome of 24.4 g of dipropyl malonic ester. The synthesis is carried out according to Example 3 with the difference that, instead of aluminum bromide, anhydrous aluminum chloride is used, which is purified by sublimation immediately before synthesis. The yield of 2,2-diprop1-1,3-propanediol is 14.5 g (90.0% 5 of the theoretical).

Example 8: Starting from 38 g of aluminum bromide, immediately prior to synthesis, taken from a sealed ampoule, 75 ml of diglyme, 150 ml of ethyl ether and 65 g of dibutyl malonic ether. The synthesis is carried out according to Example 3. The 15 o-1b6 / 6 mm Hg fractions are collected. , - which solidifies into colorless crystals with m.p. 59-61 ° C. The yield of the product 5 (2,2-dibutyl-1,3-propanediol) is 35.8 g (79.5% of the theoretical).

Example 9. Synthesis was carried out according to Example 3 with the difference that aluminum bromide was used, immediately before synthesis, taken from a sealed ampoule. The yield of the target product (2,2-DIPROPIL-1,3-propanediol) is up to 83.2% of the theoretical one).

The use of the invention allows to simplify the process by using low volatile raw materials and fireproof sodium borohydride, as well as by excluding the corrosive alkali from the composition of the reaction mixture.

Claims (2)

METHOD FOR PRODUCING 2-SUBSTITUTED OR 2,2-SUBSTITUTED 1,3-PROPANDIOLES, characterized in that, in order to simplify the process, the alkyl or dialkyl malonate is reduced with sodium borohydride in the presence of a metal halide selected from the group: calcium chloride, aluminum bromide, aluminum chloride , in a solvent medium selected from the group: tetrahydrofuran, diglyme, monoglyme, diethyl ether or mixtures thereof, at the boiling point of the reaction mixture.