DER0010684MA - - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

Filing date: January 12, 1953 Advertised on November 8, 1956

GERMAN PATENT OFFICE

PATENT APPLICATION

CLASS 12 ο GROUP 19o3 INTERNAT. CLASS C 07c

R 10684 IVb / 12 ο

Dipl.-Chem. Dr. Walter Grimme, Utfort via Moers,

and Dipl.-Chem. Dr. Hans Emde, Homberg (Ndrh.)

have been named as inventors

Rheinpreussen Aktiengesellschaft für Bergbau und Chemie

Homberg (Ndrh.)

Process for the preparation of esters of tertiary Acetylene carbinols

It is known that ketones and acetylene form tertiary condensation agents in the presence of alkaline condensation agents Acetylene carbinols of the general formula

R ₁ -CC =

OH

ίο form in which R ₁ and R _{2 are} aliphatic, aromatic or hydroaromatic hydrocarbon radicals or

τ? ^x

represent a hydroaromatic hydrocarbon radical. In this way z. B. 3-Methylpentin-iol- (3) accessible from methyl ethyl ketone and acetylene in the presence of sodium amide in liquid ammonia. These tertiary acetylene carbinols are characterized by their high reactivity, which is expressed through Possibilities of attachment to the triple bond and through possibilities of rearrangement, which include of the tertiary OH group lead to unsaturated ketones. On the other hand, reactions are the Alcohol group is difficult to carry out while maintaining the structure of the tertiary acetylene carbinols, since they are tertiary alcohols. Experience has shown that such tertiary carbinols are only amenable to esterification or etherification under severe conditions.

Contrary to these general experiences, it has now been found that such esters are

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can produce booty if tertiary acetylene carbinols of the above formula with acid chlorides are more aliphatic or aromatic carboxylic acids in counter

^: waited by organic. Bases are implemented in the absence of water at low, normal to water bath temperature. In this way z. B. by using acetyl chloride or benzoyl chloride, the acetic acid or benzoic acid esters of the tertiary acetylene carbinols accessible with good yield. The smooth reactivity of the acid chlorides is surprising, since it is known that tertiary alcohols generally do not react with acid chlorides, for example acetyl chloride, or only with poor yields to form esters. The smooth reactivity of the acid chlorides. of aliphatic and aromatic carboxylic acids also appears unusual because sulfonic acid chlorides do not lead to the desired sulfonic acid esters of tertiary acetylene carbinols under similar conditions.

Pyridine, quinoline and the like, for example, can serve as organic bases.

The esters of the tertiary acetylene carbinols produced in this way are more organic as intermediates Syntheses and important because of their pharmacological effectiveness. So is z. B. the hypno-

· ■ - · - ■ the effect of these esters compared to the known effect of the unesterified acetylene carbinols is increased by a multiple. '* ·.' ¹

example 1

98 g of 3-methyl-pentyn-i-ol- (3) were mixed with 98 g of dry

■ kenem pyridine mixed and this solution under Shaking the mixture drop by drop within 40 minutes with 80 g of acetyl chloride. The dark red, for Partly crystalline reaction mixture was then heated on the water bath for a further ι hour and then heated added to cooling with water. The oil layer that is deposited here was washed several times with ether extracted and the ethereal solution first with dilute hydrochloric acid and then with sodium bicarbonate solution washed. The neutral essential solution

was dried with potassium carbonate, the ether was distilled off and the residue was distilled. Bp ₇₆₀ 148 to 150 °; Z). ²⁰ 0.9281.

Example 2

..A solution of 98 g of 3-methyl-pentin-i-ol- (3) and 98 g of dry pyridine was cooled with ice and

.... shaking with 148 g of benzoyl chloride within Added dropwise for 30 minutes. After standing overnight, the reaction mixture was washed with water disassembled and then extracted with ether. The essential solution was made with dilute hydrochloric acid and sodium bicarbonate solution washed neutral and dried with potassium carbonate.

After distilling off the ether, the

The residue is subjected to vacuum distillation. Kp. _U 128 to 132 ⁰ . The yield is 151.1 g (74% of the

. Theory). D. ²⁰ 1.0265; ^ d " ⁱ » 5 ⁱ 22. Saponification number: calculated 278, found-283-

The titration with silver nitrate solution (determination of the nitric acid released) gave 99.3% the theory. .., -. ■■ ·

Example 3

! 9.Og 3-methyl-pentyn-i-ol- (3) were with 20 g mixed with dry pyridine. After this mixture had been cooled to 0 °, within 45 minutes 27 g of butyric acid chloride were added dropwise with frequent shaking. It was left in for 2 hours Stand in an ice bath and then poured the reaction mixture into ice water. The top brown colored layer was made with Ether added and the aqueous layer extracted first with ether. The ethereal solution washed neutral was dried over sodium sulfate. The ether was evaporated and the residue was the Subjected to vacuum distillation.

3-methylpentyn-i-butyrate- (3) with a boiling point of 177 ° to 178 ° was obtained as a colorless liquid. Saponification number: calculated 333, found 329.
- The titration of the acetylene group with silver nitrate solution gave 100%.

Example 4

70 g of i-ethynylcyclohexanol were dissolved in 70 g of pyridine. 83.5 g of benzoyl chloride were then added dropwise to the ice-cold mixture over the course of 15 minutes while shaking. The mixture was left to stand overnight at room temperature and then worked up as described in Example 3. After the ethereal solution has evaporated, crystallization occurs. 120.3 S (93.7% of theory) of i-ethynylcyclohexyl benzoate with a melting point of 57 to 59 ^{0 were} obtained, which can be recrystallized from isopropanol. The titration with silver nitrate solution gave 100%. Saponification number: calculated 245, found 245.

Example 5

252 g of 3-methyl-butyn-i-ol- (3) and 352 g of dry pyridine were mixed. The mixture was then admixed dropwise with 421.5 g of benzoyl chloride over a period of ¹ _{1/2 hours while cooling with ice.} It was then left to stand at room temperature overnight. After adding 1.5 l of water, the ester formed separated off as an oil. After extraction with ether, it was dried over calcined potassium carbonate and the ether was evaporated. The residue was distilled in a water jet vacuum. 448.6 g (79% of theory) of 3-methyl-butyn-i-benzoate (3) with a boiling point of 117.5 ° to 120.5 ° at 12 mm were obtained. D. ₂₀ 1.0327. Titration with silver nitrate 98.8%. Saponification number: calculated 298, found 297. ■ · ■

Example 6

A mixture of 33 g of 3-methyl-pentyn-i-ol- (3) and 33 g of dry pyridine was mixed with a mixture of 50 g of cinnamic acid chloride and 5 g of 3-methyl-pentyn-i-ol- (3) while cooling with ice vigorous shaking added drop by drop. The reaction mixture was occasionally removed from the ice bath for a short time. For post-reaction, the mixture was left to stand overnight at room temperature. After the usual work-up, the residue from the ether extract was distilled in vacuo at 0.1 mm. There were 45.1 g (65.8 ° / ₀ of theory) 3-methyl-pentin-i-cinnamate- (3) with a boiling point of 116 to 116.5 ° at °> ^{τ mm m in the} form of a yellow-

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preserved oil. Titration with silver nitrate solution 98.2%. Saponification number: calculated 245, found 245.

Example 7

The ice-cold mixture of 25.2 g of 3-methyl-pentyn-i-ol- (3) and 25 g of dry pyridine was admixed dropwise with 18 g of malonyl dichloride over a period of 2 hours. The almost completely froze and dark colored reaction product was poured into ice water and then acidified with io ° / ₀ hydrochloric acid. After extraction with ether and washing neutral with sodium bicarbonate solution, it was decolorized with activated charcoal, dried over potassium carbonate and evaporated in vacuo. The distillation in vacuo gave bis (3-methyl-pentyn-i) -malonate- (3) with a boiling point of 110 to iii ° at 0.1 mm in the form of a pale yellowish, viscous oil. Titration with silver nitrate solution 99.5 ° / ₀ . Saponification number: calculated 425, found 423.

Example 8

34.3 S 3-methyl-pentyn-i-ol- (3) and 27.7 g of dry pyridine were admixed with 23.8 g of oxalyl chloride over the course of 40 minutes while cooling with ice. After standing for two hours at room temperature, plenty of water was added and the crystalline, water-insoluble ester was filtered off with suction and washed with water. After recrystallization from isopropanol to give 27.5 g (63 ° / ₀ of theory) of bis- (3-methylpentin-i -) - oxalate (3) of melting point 66 to 68 °. Titration with silver nitrate solution 100.5 ° / ₀ . Saponification number: calculated 449, found 452.

It has already become known, primary and secondary acetylene carbinols with carboxylic acid anhydrides or chlorides or sulfonic acid chlorides in aqueous alkaline medium with lower, normal or increased Temperature to convert to the corresponding esters.

In contrast to the primary and secondary acetylene carbinols, the tertiary acetylene carbinols react under the reaction conditions given in the known process with sulfonic acid chlorides not with the formation of sulfonic acid esters, likewise the carboxylic acid esters cannot produce under these conditions. The tertiary Acetylencarbinole are still characterized by a far greater instability than the secondary acetylene carbinols.

Claims (1)

Claim: Process for the preparation of esters of tertiary acetylene carbinols with aliphatic or aromatic carboxylic acids, characterized in that tertiary acetylene carbinols of the general formula R ₁ -CC = CH OH in which R ₁ and R _{2 are} aliphatic, aromatic or hydroaromatic hydrocarbons or R ₂ represent a hydroaromatic hydrocarbon radical, with aliphatic or aromatic Carboxylic acid chlorides at low, normal or water bath temperature in the absence of water be implemented in the presence of organic bases. Considered publications:
U.S. Patent No. 2,340,701. © 609 706/401 10.56