DE1099523B - Process for the preparation of acyl derivatives of citric acid esters - Google Patents

Description

GERMAN

The invention relates to a process for the preparation of acyl derivatives of triesters of citric acid, their alcoholic components of terminally monoolefinically unsaturated aliphatic alcohols are derived.

From U.S. Patent 2,384,122 there is a method known for the production of unsaturated esters, in which, for example, triallyl citric acid ester with phosgene is acylated. However, this process has the disadvantage that the acylation is very toxic and difficult to handle Phosgene must be used.

In contrast, acyl derivatives of unsaturated citric acid esters can conveniently be used according to the invention produced by reacting citric acid esters with a carboxylic acid anhydride in the presence of an acylation catalyst. According to the invention, the implementation proceeds according to the following equation

.0

R-Cf

CH ₂ -COOR '

, Ο + HO —C-COOR '

R — c:

CH ₂ -COOR '

CH ₂ -COOR '

R — C — O — C — COOR '+ RCOOH

CH ₂ -COOR '

in which R is an alkyl radical with 1 to 18 carbon atoms or an aryl, alkaryl or aralkyl radical and R 'is a terminal means monoethylenically unsaturated hydrocarbon radical which z. B. of allyl or methallyl alcohol can be derived.

For the implementation described above, for. B. the anhydrides of the following acids:

Acetic acid,

Propionic acid,

Butyric acid,

Pelargonic acid,

Lauric acid,

Stearic acid,

Benzoic acid,

p-chlorobenzoic acid,

Anisic acid,

p-toluic acid,

Phenylacetic acid,

p-methoxyphenylacetic acid.

After the reaction, the citric acid ester acyl derivatives are isolated in a manner known per se.

The compounds prepared according to the invention are useful as coating agents for metals and textiles and as impregnating agents for all types of textiles. They can also be used in place of styrene to dissolve unsaturated polyesters which are usually solid or semi-solid at room temperature. In this case, method of manufacture
of acyl derivatives of citric acid esters

20th

Applicant:

Miles Laboratories, Inc.,
Elkhart, Ind. (V. St. A.)

Representative: Dr.-Ing. F. Wuesthoff, Dipl.-Ing. G. Pulse

and Dipl.-Chem. Dr. rer. nat. E. Frhr. v. Bad luck man,

Patent Attorneys, Munich 9, Schweigerstr. 2

Claimed priority:
V. St. v. America October 22, 1956

Willard Joseph Croxall and John Mirza,

Elkhart, Ind. (V. St. A.),
have been named as inventors

The monomeric acyl derivatives have a double task: They act as solvents for the polyester and as a reactant for the polymerization or copolymerization, to which the dissolved polyester is accessible are, as are the acyl derivatives of citric acid on their own.

example 1

A 300 cm ³ flask equipped with a stirrer, condenser and thermometer was charged with 31.2 g (0.1 mol) of triallyl citrate and 11.2 g (0.11 mol) of acetic anhydride. After stirring this solution and cooling it in an ice bath, a drop of concentrated sulfuric acid was added and then the ice bath was removed. An exothermic reaction set in, the temperature rising very rapidly to 34 ° C. After stirring for Ί hour, the mixture was heated to 50 ° C. to 60 ° C. and the reaction mixture was stirred at this temperature for a few minutes. It was then cooled and the mixture in a

Poured excess cold water. The upper oil layer was separated while the lower aqueous Layer was made alkaline by adding sodium bicarbonate and then extracted with benzene. the Benzene extracts became the original oil layer

given. The benzene solution of the oil thus obtained was thoroughly diluted first with water, then with Sodium bicarbonate solution and finally washed again with water to pn neutrality, then over Sodium sulfate dried, eventually that was

109 510/440

Benzene removed by stripping. The liquid residue was distilled in vacuo (0.2 mm Hg), the Acetyl triallyl citrate was obtained as a colorless liquid in almost quantitative yield. Boiling point: 142 to 143 ° C (0.2 mm Hg); wff = 1.4637,

Example 2

In the same way as in Example 1, 31.2 g of triallyl citrate were reacted with 28.6 g of propionic anhydride in the presence of a drop of concentrated sulfuric acid. After the reaction had ended, the reaction mixture was worked up as described in Example 1. The distillation in vacuo (0.15 mm Hg) gave a yield of 34 g (92 ° / ₀ of theory) of propionyl triethyl citrate. Boiling point: 145 ° C (0.15 mm Hg) nf = 1.4620.

Example 3

According to Example 1, 62.4 g (0.2 mol) of triallyl citrate were acylated with 34.8 g of n-butyric anhydride. This gave 69 g (91 ° / ₀ of theory) n-Butyryltriallylcitrat of boiling point 154 ° C (0.17 mm Hg); n% ^s = 1.4616.

Example 4

A 300 cm ³ flask with a stirrer, condenser and thermometer was charged with 31.2 g of triallyl citrate and 29.8 g of pelargonic anhydride and a drop of concentrated sulfuric acid. The solution was heated to 80 ° C. with stirring. It was held at 75 to 80 ° C for 2 hours. The solution was then cooled to 30 ° C. and poured into an excess of ice water. The oil layer formed was taken up in 100 cm ^{3 of} benzene. The aqueous layer was made alkaline with sodium bicarbonate and ^{extracted with 50 cm 3 of} benzene. The benzene solutions were combined, first with water, then washed and finally at 10 ° / ₀ sodium bicarbonate again with water until neutral. The combined benzene solutions were dried over anhydrous sodium sulfate, the drying agent was filtered off, then the benzene was removed by vacuum stripping (14 mm Hg). The product of the reaction was pelargonyl tri-uyl citrate.

Example 5

In the same way as in Example 4, 38.2 g of lauric anhydride were reacted with 31.2 g of triallyl citrate brought. After completion of the reaction, the reaction product sat as a waxy, solid lauric acid-containing substance. This crude product was dissolved in petroleum ether, the lauric acid by washing out removed with sodium bicarbonate solution. After stripping off the petroleum ether at 15 to 20 mm Hg Lauroyl triallyl citrate can be isolated.

washing with sodium bicarbonate solution and water, the benzene solution was over anhydrous sodium sulfate dried. Stripping off the benzene and distilling under reduced pressure (0.18 mm Hg) gave Benzoyl triallyl citrate (145 to 147 ° C).

Example 7

In the same way as in Example 6, 25.4 g of phenylacetic anhydride and 31.2 g of triallyl citrate were in Reaction in the presence of a drop of sulfuric acid. When working up the reaction mixture like Phenylacetyl triallyl citrate was obtained above.

Claims (3)

PATENT CLAIMS: 1. Process for the preparation of acyl derivatives of the citric acid esters of the formula Example 6 55 A mixture of 25.5 g benzoic anhydride and 31.2 g triallyl citrate became more concentrated with one drop Treated sulfuric acid and heated to 60 ° C for 30 minutes with stirring. Then you left that The mixture stood for 1 hour, then it was poured into ice water and the oil taken up with benzene was separated off. After departure CH ₉ -COOR ' R — C —O — C — COOR ' CH ₂ -COOR ' in which R is an alkyl radical having 1 to 18 carbon atoms or an aryl, alkaryl or aralkyl radical and R 'is a represents terminal monoolefinically unsaturated hydrocarbon radical, characterized in that that one has a citric acid ester of the formula CH ₂ -COOR '
HO - C - COOR '
CH ₂ -COOR ' in which R 'has the meaning given above, with a carboxylic acid anhydride of the formula R-C- :O R-C in which R has the meaning given above, in the presence of an acylation catalyst at increased Reacts temperature and the product obtained is isolated in a known manner. 2. The method according to claim 1, characterized in that one is used as the acylation catalyst strong inorganic acid, especially sulfuric acid, is used. 3. The method according to claim 1 or 2, characterized in that the acylation is carried out at temperatures up to about 80 ° C. Considered publications:
U.S. Patent No. 2,384,122. © 109 510/449 2.61