SU1601097A1 - Method of producing alpha-acetylene ketones - Google Patents

Abstract

The invention relates to unsaturated ketones, in particular to the preparation of α-acetylene ketones in the form of CH ₃ -C (O) -C = CR, where R = PH, CH ₂ OH, which are used as intermediates in organic synthesis. In order to simplify and intensify the process and increase the yield of the target product, ethynyl magnesium bromide is reacted with 2,4,4-trimethyl-1,3-dioxane, followed by treatment of the resulting mixture with an aqueous acid solution. Output 80% (vs. 8% by a known method). The method makes it possible to shorten the reaction time by 3 times and simplify the process by carrying out the reaction at room temperature.

Description

This invention relates to the field of organic chemistry and relates, in particular, to a process for the preparation of oi-acetylene ketones of the general formula

ABOUT . CH, -C-C C-R 1

I 3

where R Ph, CHgOHj

which are used as intermediates in organic synthesis.

The purpose of the invention is to simplify and intensify the process and increase the yield of the target product.

Example 1. 1-phenyl-1-butyn-3-one (1a).

To the Iocic reagent obtained from 9.5 g (0.0 mol) of magnesium, 47.7 t (31.5 ml, 0.44 mol) of ethyl bromide in 75 ml of ether, 40.8 g (43 ml, 0 , 40 mol) of phenylacetylene in 50 ml of ether is powdered in portions of 29.5 g (0.13 mol) of 2,4,4-trimethyl-1,3-dirxani perchlorate for 20 minutes at 20 ° C (ambient temperature ). The mixture is then decomposed with 50 ml of water and 75 ml of 10% HC1 while cooling with ice. The mixture is stirred for 2. h at the boiling point of the organic layer in a water bath at 50 s. Upon cooling, the ether layer is separated, neutralized with a 5% solution of Naj, C03, washed with water and dried with anhydrous sodium sulfate. After distilling ester5

about

with

s

pa in a water bath the residue is fractionated under vacuum. 15.8 g of ketone (la) are obtained and 2.1 g of phenylacetylene are returned. Bp 115 - (5 mm byst.st.); yield k, k% (from theory to dioxane salt), 7.1, k% (from theory to taken phenylacetylene).

Found,% C 81.2; H 6.7. With 0 HgO.

Calculated% C 81.07; H 6.59. IR spectrum, cm-: 3080, 2200, 1685, 1580, 1600, 1500, I t50, 1150, 1020, 980, 76Q.

HMR-spectrum (in CC14 5 vol.% GDV): 7.16 c./(CgH5), 2.17 s.ms. (SNE).

Example II. Analogously to Example 1, Iocim's reagent obtained from 0.40 mol (40.8 g) of phenylacetylene was used, and 0.20 mol (45.6 g) of perchlorate 2 was added to it, 4,4-trimethyl-1, 3 dioxane. Obtained by distillation in vacuum of 20.5 g of phenylacetylene and 23.9 g of acetylphene acetylene (la)

4-he (1b); It is prepared as described in Example 1 and from 3.8 g (0.2 mol) of magnesium, 29.1 g (20 ml, 0.27 mol) of ethyl bromide in 70 ml of ether, and 11.3 g. (0.2 mol) propargyl alcohol in 30 ml of ether by adding 45.7 g (0.2 mol). 2,4,4-trimethyl-1,3-dioxane perchlorate for 30 minutes at 15 ° C. 8.2 g (42%) of ketone (16) are obtained. Bp 109 ° C (50.mHg).

Found,%: C b1, 4; H 6.42. CjH gO ,.

Calculated,%: C 61.2; H 6.12. 15 IR spectrum, cm: 3400, 2200, 1680,

1590, 1580, 1480, 1250, 2240, 1050, 1010, 950, 810, 730.

EXAMPLE 7 In a manner similar to Example 1, the use of the Jocicha reagent obtained from O, g mole (10.2 g) of phenylacetylene was used, and added to it at 0 ° C for 1 h 20 min. 0.1 mol (22.8 g) of perchlorate 2, 4,4-trimethyl-1,3-dioxane. 11.5 g of ketone (la) are obtained.

Output 83 (from the theory to the salt of diox- 25 Output 80 (from the theory to the salt of dioxanes), 4TI (from the theory to the pheny taken), -801 (from the theory to the taken phenylacetylene)

nylacetylene).

35

PRI m ime 3. Analogously to example 1, the use of the Iocich reagent obtained from 0.1 mol (10.2 g) of phenylacetylene and 0.1 mol (22.8 g) of perchlorate 2.4, 4-trimethyl is used. -1, 3-dioxane. 11.5 g of acetylphenylacetylene (la) are obtained. Yield 801 (from theory to dioxane salt), 80% (from theory to phenyl cetylene taken).

PRI me R 4. Analogously to Example 1.1, the use of the Iocich reagent obtained from 0.1 mol (10.2 g) of phenylacetylene and 0.15 mol (34.2 g) of 2,4,4-trimethylgl perchlorate perchlorate is used. Dioxani 8.6 g of feton (la) are obtained. Yield 40% (from the theory to the salt of dioxia), 60% (from the theory to the phenylacetylene taken).

EXAMPLE 5 Analogously to Example 1, the Io-jobych reagent obtained from 0.35 mol (35.24 g) of phenylacetylene and 0.1 mol (22.8 g) of 2,4,4-trimethyl- perchlorate is used. 1, 3-dioxane. 9.3b g of acetylphenylacetylene and 20.0 g of phenylacetylene are obtained. Yield b5% (from theory to dioxane salt), 19% (from the theory taken phenylacetylene). PRI me R 6, 1-Oxy-2-pentin30

4-he (1b); In the same way as described in example 1 and below, 3.8 g (0.2 mol) of magnesium, 29.1 g (20 ml, 0.27 mol) of ethyl bromide in 70 ml of ether, and 11.3 g (0.2 mol ) propargyl alcohol in 30 ml of ether by adding 45.7 g (0.2 mol). 2,4,4-trimethyl-1,3-dioxane perchlorate for 30 minutes at 15 ° C. 8.2 g (42%) of ketone are obtained (16). Bp 109 ° C (50.mHg).

Found,%: C b1, 4; H 6.42. CjH gO ,.

Calculated,%: C 61.2; H 6.12. IR spectrum, cm: 3400, 2200, 1680,

1590, 1580, 1480, 1250, 2240, 1050, 1010, 950, 810, 730.

Output 80 (from the theory to the salt of dioxane), -801 (from the theory to the taken

nylacetylene).

Thus, the preparation of ob-acetylene ketones allows to increase the yield of the target products up to 80% against 8% by a known method, shorten the reaction time by three times and simplify the process by conducting the reaction at room temperature.

Claims (1)

Formula of iso and N The method of obtaining oi-acetylene ketones of General formula ABOUT  II сНз-с-с с-к  where R is Ph,,. on the basis of the corresponding ethynyl-Mgnibide bromide, which differs in that, in order to simplify and intensify the process and increase the yield of the target product, ethynyl magnesium bromide is reacted with 2,4,4-trimethyl-1,3-dioxane, and the resulting mixture is treated with aqueous acid solution.