SU113687A1 - Method for producing macrocyclic lactones and oxalactones - Google Patents

Description

Known methods of synthesizing cyclic cyclic compounds are based on expensive raw materials, include a large number of chemical reactions, and provide small yields of the product.

The main difficulty in the treatment of macrocyclic compounds is the synthesis of normal o-hydroxy carboxylic acids.

According to the invention, higher tetrachloroalkanes (Cd-Ci7) are used as raw materials for obtaining macrocyclic lactones and oxalactones, which are much cheaper than known types of raw materials and transformed into lactones in three stages with higher yields.

The conversion of higher tetrachloroalkanes into lactones proceeds as follows;

C1 (SN.CL CC1-C1 (SN.D., UNC-BUT (SN.C., UNC-

tetrachloroalkan Na SO chloric acid

Chloric acids obtained from tetrachloroalkanes can be converted into macrocyclic oxalactones by reaction with dihydric alcohols (glycols):

С1 (СН,), СООH + НО (СНо) „, (СН ,, 0 (СН2)„ СООH-chloro-acid glyclyloxy-oxo-acid

 SNO) „С О

0- I

macrocyclic lactone

- (sn.o „- about о о -) о

(CH,) „oxalactone

JVo 11368

According to the proposed method, lactones and oxalactones can be obtained, in which, 10, 12, 14, 16 and m 2, 4, 6. For the synthesis, not only individual tetrachloroalkanes are used, but also coarse fractions (mixtures) containing 2-3 components, extracted from the initial mixture of tetrachloroalkanes by vacuum distillation, distillation of water vapor, ethylene glycol, and glycerol under reduced pressure in a stream, selective extraction with volatile solvents (alcohol, acetone, etc.). The lactones and oxalactones, possessing high thermal stability, are divided into individual components by vacuum distillation.

The method is carried out as follows.

Getting o-chloroacids. 1 weight. including tetrachloroalkane (or a mixture of tetrachloroalkanes) is mixed with 2 weight. including concentrated HNOs (sp. weight 1.5-1.52) or H2SO4 (sp. weight 1.83). The mixture was incubated for 2-3 hours. when moved and heated to 65–70 ° for HMOS and to 90–95 ° for H2SO4. At the end of the reaction, the theoretical amount of gaseous HC1 is released. At the end of the process, the reaction mixture is cooled, diluted with water and extracted with chloroform or carbon tetrachloride. The extract is washed with water, dried and the solvent is distilled off. The residue is fractionated in vacuo to obtain chloric acids with a yield of 60-80% of theoretical.

Conversion of chloric acids to hydroxy acids and lactones. 1 mole of chloroacid (or mixtures of chloroacids) is displaced from 1 l of an aqueous alkaline solution containing 50 g of NaOn and 100 g of a2CO3 and placed in an autoclave. The reaction is carried out at 140-150 ° for 3 hours; the pressure in the autoclave is 5-7 atm.

At the end of the reaction, 1 l of 10% KOH solution is added to the reaction mixture, boiled for 1.5-2 hours, cooled to 50-60 °, 50-100 ml of ethyl alcohol are added and filtered hot. Upon acidification of the filtrate with hydrochloric acid, α-oxyhelids are released as a rapidly crystallizing oily precipitate. The hydroxy acid crystals are separated from the mother liquor on the filter, washed with water and air dried. The yield of hydroxy acids is 80-90% of theoretical. Hydroxy acid lactones are produced in a well known manner.

The conversion of chloro acids into hydroxy-hydroxy acids and oxalactones.

In a flask load 4-6 moles of glycol, 200 g 40; | a solution of NaOH and 3 l of isoamyl alcohol. The mixture is heated to boiling and. water

introduced with reagents, and also about) by reaction.

but (CH2), "OH- | -NaOH-NaO (CHg) ,,, OH-LHgO, is distilled off with isoamyl alcohol vapors.

After the water is distilled off, the temperature of the mixture is raised to 160 °. In the last episodes of isoamyl alcohol, the water content should not exceed 0.05%.

At the end of the removal of isoamyl alcohol, 1 mole of chloro-acid (or mixtures of go-chloro-acids) is added to the flask with stirring and heating to 120-130 °. Then the temperature of the mixture is increased to 140-160 °, maintain the mixture for 4 hours. and the excess glycol is stripped off in vacuo.

The resulting " -Oxy-oxcarboxylic acid salt of the general formula HO (CH2) ' g-O- (CH2) - - COONa is dissolved in water and upon acidification, the free acid is separated, which is separated and washed with brine.

The resulting n-hydroxycarboxylic acid without purification is used for further processing in a known manner.