SU789509A1 - 5-acetoxyvaleric acid as intermediate product in synthesis of 15-hydroxypentadecanoic acid and its preparation method - Google Patents

Description

(54) 5-ACETOXIVALERIAN ACID AS AN INTERMEDIATE PRODUCT IN THE SYNTHESIS OF 15-OXYPENTADECANIC ACID

This invention relates to a novel compound of 5-acetoxyvaleric acid as an intermediate in the synthesis of 15-hydroxypentadecanoic acid and a new method for its preparation.

A known method for producing 15-hydroxypentadecanoic acid is based on the use of undecylenic acid obtained from a scarce vegetable raw material, castor gold.

A known method for the synthesis of 15-hydroxypentadecanoic acid from 5-acetoxyvaleric acid and decanecarboxylic-1-10 acid monoethyl ester, in which the yield of the target product is increased by more than 2 times, the process is transferred from natural to chemical raw material t} 5-Acetoxyvaleriane. acid, its properties and method of preparation are not described. Only its methyl ester is known, hydrolysis: which leads not to 5-acetoxyvaleric acid, but to cf-valerolactone 3.

The purpose of the invention is 5-acetoxyvaleric acid, as an intermediate product in the synthesis of 15-hydroxypentadecanoic acid and a method for its preparation. AND METHOD OF OBTAINING IT

These properties are determined by the chemical structure of 5-acetoxyvaleric acid, which is expressed by the formula CHnCOO-CHn-CH-CHijj-CHfj-COOH.

The 5-acetoxivaleric acid is colorless, the liquid is clear with m.p. 116 ° C at 0.5 mm;, 4383,, 1150. Soluble in ether, methylene chloride, alcohol, acetone,

10 benzene, toluene.

5-Acetoxyvaleric acid is a bifunctional compound containing acid and ester groups. Its structure is uniquely determined by the data of functional, elemental and spectral analyzes, as well as the determination of molecular refraction.

Data functional analysis.

20

Found KOH, mg: acid number (r.h.) 347.5; ethereal number (e.h.) 350.

350,

Calculated by KOH, mg: k.ch. el.ch. 350

25

Elemental analysis data. Found,%: C 52.50, 52.23; H 7.59,

.7.42.

Stn ,, od

Calculated,%: C, 52.49; H, 7.55.

thirty

Molecular Refraction.

MR 37.76.

Found:

O, H,., O,

.

Included: 37,72.

IR spectrum data.

IR spectrum (S,): 1048, 1241, 1748 (CH & COO), 1718 (COOH), 25003300 (HE).

Data spectrum PMR.

NMR spectrum (cf, ppm) 1, b8 (complex multiplet) (CHjCIi, 2.01 (singlet) (CHj, 2.36 (complex multiplet (CH (), 4.00 (complex multiplet) (OCH ( j), 10.13 (broad singlet) (COOH).

5-Acetoxyvaleric acid is obtained by treating with acetic acid (acetolysis of 5-chloro-valeric acid or C / -valerolactone or its polymer, or a mixture of cf-valerolactone and its polymer with a high-boiling fraction, which is formed during the treatment with acetic acid of 5 hlororalerianic acid or f-le. or its polymer at llO -lScPc The yield of the target product.

The process can be carried out at a pressure of from 1 to 3 atm and in the presence of a catalyst, such as sulfuric acid or KU-2-8 sulfonic cation exchanger, which allows to intensify the process.

Acetolysis of 5-chloro-valeric acid can be carried out by heating it with sodium or potassium acetate in an acetic acid medium (molar ratio of reagents 1: 2: 4) at a boiling point of the reaction mass of 125-135 s. The formation of 5-acetoxyvaleric acid is an equilibrium process, and the equilibrium is established in 18-24 hours. 5-acetoxyvaleric acid is isolated from the reaction mixture (yield 50-55% of theoretical), O-valerolactone (10-40 wt.%) And high-boiling Condensate fraction (0-30 wt.%, t. Kip. 150 at 1-2 mm). The latter contains the product of the acidolysis of o-valerolactone 5-acetoxyvaleric acid. When water is added to the reaction mass (7-10% by weight of acetic acid), the yield of the target product increases by 10-15%. Similar results are obtained using sodium or potassium carbonates, which react with acetic acid to form the corresponding acetates, water, and carbon dioxide. The optimal molar ratio of the reactants — 5-chlorovaleric acid, sodium carbonate (or potassium) and acetic acid in this case is 1: 1: 6.

The yield of 5-acetoxyvaleric acid in the proposed conditions reaches 55% of the theoretical. The CI-valerolactone formed as by-products and the high-boiling fraction are subjected to repeated acetolysis.

Acetolysis (-valerolactone is carried out mainly by heating with 90-93% acetic acid at a molar ratio of reagents of 1: 4.6 in the absence of catalysts at a boiling point of the reaction mass of 112-115 ° C. In this case, to achieve equilibrium a longer time — 36–48 hours, and a mixture of the same products is obtained: 5-acetoxyvaleric acid is extracted from the reaction mixture (yield 56–58% of theoretical) CЯ-valerolactone (7–13 wt.%) and a high boiling fraction ( 27-40 wt.%). The total yield of 5-acetoxyvaleric acid while n vyshaets to 77%. The resulting by-products is recycled in the process.

Acetolysis can also be subjected to CP-valerolactone polymers. The magnitude of the molecular weight (determined by the ebullioscopic method) within the limits studied (136-980) does not affect the reactivity of these compounds.

The duration of the reaction of acetolysis of CG -valerolactone can be significantly reduced either by using catalysts or by increasing the reaction temperature by holding it under pressure. The best results were obtained in the presence of KU-2-8 sulfonic cation exchanger in n-form.

The yield of 5-acetoxyvaleric acid after 6 hours of heating with KU-2-8 was 54.5%, after 12 hours - 60.5% (outputs in control experiments without a catalyst were 21 and 30%, respectively), and using side products - 72.7 and 75% sootBSTCTBeEiHO. When using 0.1 wt.% Of sulfuric acid as a catalyst, the yield of 5-acetoxyvaleric acid after 6 hours of heating is 35-36%. Increasing the duration of the reaction, as well as varying the amount of sulfuric acid did not lead to an increase in the yield of the target product.

With an increase in the reaction temperature to 1500 ° C (pressure 2.5-3 atm), the yield of 5-acetoxyvaleric acid after 6 and 12 hours was 39.6 and 36.6%, respectively.

The proposed method makes it possible to obtain 5-acetoxyvaleric acid, both from 5-chloro-valeric acid and from tf-valerolactone and high-boiling fractions produced as by-products, with high consumption, thus minimizing the loss of the main substance. The sodium chloride formed during the acetolysis of 5-chloroalerianic acid can be used in the preparation of a saline solution for washing the reaction product. Sodium acetate and acetic acid, used in excess, can be recycled to the process. With the acetysis of cG-valerolactone and high-boiling effluent fractions, there is almost no waste.

Example. b-Acetoxyvaleric acid.

To a solution of 82 g (1 mol) of sodium acetate in 129 g of 93% acetic acid was added 71 g (0.5 mol). 96.4% of 5-chloro-valeric acid and boiled with stirring for 18-24h (temperature of the reaction mixture 1201250s). After cooling, the resulting sodium chloride is separated and about 80% by weight of acetic acid is distilled off in a vacuum (150-50 mm), ether or methylene chloride is added to the residue, excess sodium acetate is filtered off and the extract is taken up in brine. After distilling off the solvent and vacuum distillation of the product of acetolysis, 40.7 g (50.8%) of 99% 5-acetoxyvalerianic acid are obtained (bp 147-149s at 2 mm, n 1.4387, and part 346 , 2, e.h. 350.0), 9/8 g of a mixture () (f-valerolactone and 5-acetoxyvaleric acid (so kip. 80-147 at 3 mm, p 1.4471) and 15.7 g fraction

20 te with t. Kip. 200-220 0 at 2 mm, p 1.4513, k.ch. 225.0, e.h. 417.2.

During repeated vacuum distillation, 5-acetoxyvaleric acid has a so-called bale. 116 ° Spri 0.5 mm, 4383 1.1150, r.ch. 347.5, e.h. 350.0. 4 „... a. (-, 52,, 50, 52.23;

Found

MR-JJ 37.76. H 7.52, 7.42

C-hH, d.

Calculated,%: C, 52.49; H 7.55; MRj) 37.72, k.ch. 350.0, e.h. 350.0 m KON. IR (SSRd) (t cm): 1048 1241, 1718, 1748, 2500-3400. PMR spectrum (in CCE4):

2.01

Sin-Complex multiplet Broadened

A mixture of 9.8 g of CJ -valerolactone and 15.7 g of a high-boiling fraction is boiled for 36-48 h with 100 g of 90-93% acetic acid (temperature of the reaction mass is 110-113 C). The excess acetic acid is distilled off in vacuo, and after vacuum distillation of the residue, 19.5 g of 97% 5-acetoxyvaleric acid with rR1.4392 are additionally obtained. A total of 60.2 g of 5-acetoxyvaleric acid is obtained, which is 75% of the theoretical per 5-chloro valeric acid.

Example 2. 5-Acetoxyvalerianic acid.

To 252 g (4.2 mol) of acetic acid, 76.5 g (0.7 mol) of soda ash was added, and then 99 g (0.7 mol) of 96% 5-chloro valeric acid and boiled with stirring. 18-24 h. After the treatment of the product and vacuum distillation described in Example 1, 62.4 g (55.4%) of 98% 5-acetoxyvalerivanoic acid, m.p. 154-1570С (at 6 mm, 1.4381, rms 346.5, e. 35r, 7. 24 g of a mixture (A3: 1) are also obtained (I-valerolactone and 5-acetoxyvalerianic acid, t. Kip, 100-150 ° C at 6 mm, p ™ 1.4475 from which, after boiling with 9093% acetic acid, 18.3 g of 5-acetoxyvaleryanoic acid are additionally obtained. The total yield of 5-acetoxyvaleric acid is 71.7 %

Example 3: 5-Acetoxyvaleric Acid.

10.13

2.36

1.68

4.00

singlet

to 181 g (3 mol) of acetic acid, add 69.1 g (0.5 mol) of potash, and then 71.2 g (0.5 mol) of 96% 5-hlorodaleric acid and boil with stirring 18-24 h. After the treatment and the vacuum distillation indicated in Example 1, 43.9 g (54.7%) of 5-acetoxyvalerian acid, so kip are obtained. 135-137 with at 1 m,, 4375, k.ch. 339.2, e.ch. 352.0. At the same time, 2 g of polymer SG-valerolactone, t. Bale, is obtained. 60133 ° at 1 mm, and 17.1 g of high boiling fraction, t. Bale. 160-213 C at 1 mm, PR 1.4510, of which, by boiling with 90-93% acetic acid, 17.8 g are additionally obtained

5 5-acetoxyvaleric acid. The total yield is 61.7 g, which is 77%.

Example 4. 5-Acetoxyvalerianic acid.

A mixture of 30 g (0.3 mol) of C -valero0 lactone and 115.5 g of 90-93% acetic acid is boiled for 36-48 hours. After distillation of the acetic acid and vacuum distillation, 27.1 g (56.5% of ) 5-acetoxyvaleric acid, t. Kip. 142-147 0 at 2 mm, p 1.4390,

5 k.ch. 338.1, e.h. 355.7). At the same time, 3.2 g of the polymer are obtained (I-valerolactone and 9.9 g of the high-boiling fraction, t.p. 150-220 ° C at 2 mm, 1.4949, of which

0 acetolysis, in the conditions described above, additionally obtain 10 g of 5-acetoxyxivaleric acid. The total yield is 37.1 g, which is 77.1% on the starting-cG-to aerolactone.

Claims (3)

f Example 5. 5-Acetoxyvalerianic acid. 30.7 g (0.3 mol) of cf-valerolactone and 119 g of 90-93% acetic acid are heated with stirring in an autoclave at 150 ° С (pressure 2.5-Zatm for 6 hours. After treatment, 19 , 6 g (39.8%) of 5-acetoxyvaleric acid, bp 152-160 0 at 6 mm,, 4387, parts of 336.1, e, 355.9 and return 9.9 g -valerol tone., Example 6. 5-Acetoxyvaleric acid. 30.7 g (0.3 mol) of CP-shaft) 6olacto is boiled with 1.84 mol of 90-93% acetic acid in the presence of a cation exchange resin KU- 2-8 for 6h. After the usual treatment, 26.8 g (54.5%) of 5-acetoxyvaleric acid are obtained, t. Bale. 161-167 0 at 9 mm, 4381, k.ch. 347.2, e.h., 353.5. 7.0 g of cf-valerolactone and 5.75 g of a high boiling fraction, i.e. bale are also obtained. 240-243 0 at 9 mm. When heated for 12 hours, the yield of 5-acetoxyvaleric acid is 60.5%. After processing of by-products, the total yield of 5-acetoxyvaleric acid will be, respectively, 72, 7 and 75%. Example 7. The south (0.1 mol) of t-valerolactone and 30 g (0.5 mol) of acetic acid is boiled for 6 hours in the presence of 0.01 g of sulfuric acid. Acetic acid is distilled off from the reaction mass, methylene chloride is added to the residue and washed with brine until neutral. After distilling off the solvent and vacuum distillation, 5.8 g (36.1%) of 5-acetoxyvaler1-anoic acid are obtained, t. Bale. 129-1350s at 1 mm, 4390, k.ch. 334, .6, e.h. 350.6, 1 g of polymeric O-valerolactone and 5.28 g of high boiling fraction, t. Bale. 180-23 bps at 1 mm, p 1 4540. Claim 1.5-Acetoxyvaleric acid of the formula CHj, COOH-CHQ-CHg-CH-CHg-COOH, as an intermediate product B for the synthesis of 15 hydroxypentadecanoic acid. 2. A method for producing a compound according to claim 1, characterized in that 5-chloro valeric acid or c-valerolactone or its polymer or a mixture of cp-valerolactone and its polymer with a high boiling fraction formed during the treatment with acetic acid of 5-chloro-maleic acid or s- valerolactone or its polymer is treated with acetic acid at a temperature of from 110 to. 3. A method according to claim 2, characterized in that the process is carried out at a pressure of from 1 to 3 atm. Sources of information taken into account during the examination 1.Belov V.N. and other Synthesis of macrocyclic lactones. Sb. Trudy VNIISNDV, vyp.IV, M., Pishepromizdat, 1958, p. 3 2. USSR author's certificate for application number 2159427 / 23-04, dated August 31. 76, 3.Gnest NN, Isomeric chlorinated long-chain esters. L.Am. Chem. Soc., 69, 300, 1947.