JPS5911592B2 - Method for producing 2-oxazolidinone compound - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing various 2-oxazolidinone compounds in high yield from various amino alcohols and carbon dioxide.

2-Oxazolidinone compounds are useful substances as raw material intermediates for polymeric materials, medicines, agricultural chemicals, etc., or as additive components for various compositions, and many production methods have been proposed so far.

Among these production methods, a method of reacting amino alcohol and carbon dioxide (US Patent No. 252975187)
The method (specification) has the advantage of being able to use raw materials that are easily available and easy to handle, and that the reaction proceeds relatively easily, and is attracting attention as an industrial production method. It must be carried out under suitable conditions, and
The drawback is that the yield is 30% lower.

The present inventors have conducted extensive research in order to overcome the drawbacks of such conventional methods and to develop a method that can produce 2-oxazolidinone compounds in good yield under mild conditions. The inventors have discovered that the target compound can be obtained in high yield even under relatively mild conditions by carrying out the reaction in the presence of 35, and based on this finding, the present invention has been accomplished.

That is, according to the present invention, R1, R2, R3, and R4 are the same or different, and each is a hydrogen atom, an alkyl group, or an aryl group, or any two of them are connected. and R5 is a hydrogen atom or an alkyl group) with carbon dioxide in the presence of carbodiimide in a solvent to form an alkylene group. R1, R2, R3,
R4 and R5 have the same meanings as above)
-An oxazolidinone compound can be produced in high yield.

As for the amino alcohol represented by the general formula (1) used as a starting material for the method of the present invention, R1, R2, R3 and R4 are hydrogen atoms, alkyl groups or aryl groups,
R, is a hydrogen atom or an alkyl group, such as 2-
Aminoethanol, 2-aminopropanol, 2-aminobutanol, 1-aminopropan-2-ol, 1-
Aminobutan-2-ol, 2-N-methylaminoethanol, 2-N-ethylaminoethanol, 2-amino-2-methylethanol, 2-amino-1-phenylethanol, etc., R1, R2, R3 and R4 Any two of these are linked to form an alkylene group,
Examples include 2-aminocyclohexanol, 2-N-methylaminocyclohexanol, and 2-aminocycloheptanol.

The carbodiimides used as condensing agents in the method of the present invention include, for example, symmetrical dialkylcarbodiimides such as diisopropylcarbodiimide and dibutylcarbodiimide, symmetrical arylcarbodiimides such as di-p-carboethoxyphenylcarbodiimide, and symmetrical arylcarbodiimides such as synchrohexylcarbodiimide. Mention may be made of cycloalkylcarbodiimides and asymmetric carbodiimides such as cyclohexylisopropylcarbodiimide, cyclohexylisopropylcarbodiimide, cyclohexylphenylcarbodiimide, butylphenylcarbodiimide.

The amount of these carbodiimides used is approximately an equimolar amount to the amino alcohol as a raw material, but an excess amount can be used if necessary.

The reaction solvent in the present invention is not particularly limited as long as it is an aprotic solvent, and for example, acetonitrile, ether, tetrahydrofuran, dioxane, acetone, methyl ethyl ketone, benzene, toluene, xylene, dimethylformamide, dimethylacetamide, etc. are preferably used. Carbon dioxide is usually supplied from cylinders, but
Pressure from normal pressure to 50 kg/Crli, preferably several kg
/Cd to 201<g/Cr! It is supplied at a pressure of i.

The reaction temperature ranges from room temperature to about 250°C, preferably from 50 to 150°C. The reaction time requires 2 hours or more at low temperatures, but 2 hours is sufficient at around 100°C. In the present invention, it is preferable to add a tertiary amine because it shortens the reaction time and increases the yield.

The tertiary amines to be added include triethylamine,
Aliphatic tertiary amines such as tributylamine, aromatic tertiary amines such as dimethylaniline and diethylaniline, pyridine, picoline, colicin. ．． Examples include heterocyclic compounds having a tertiary nitrogen atom such as quinoline and isoquinoline. The method for producing 2-oxazolidinone of the present invention can obtain various 2-oxazolidinones in high yield from ethanolamine having various substituents and carbon dioxide under conditions of relatively low temperature and low pressure, so it has industrial utility value. This can be said to be a highly effective method.

Next, the present invention will be explained in more detail with reference to Examples. Example 1 6.1y (0.10 mol) of ethanolamine, 11.47 (0.11 mol) of triethylamine, 22.77 (0.11 mol) of synchronohexylcarbodiimide, and 100 ml of dioxane were placed in a 300 ml autoclave with vertical stirring, The reaction was carried out at 60° C. for 2 hours at an initial pressure of carbon dioxide of 10 kg/Cd.

Synchlohexyl urea produced from the reaction mixture was filtered off, and the solvent in the filter solution was distilled off under reduced pressure. The residue was dissolved in water and cooled to separate the solids. When water is distilled off from an aqueous solution under reduced pressure and the residue is washed with cold methanol, 6.4
7 crude 2-oxazolidinone was obtained. Yield based on ethanolamine is 74%. When this was recrystallized from chloroform, pure 2-oxazolidinone with a melting point of 88-89°C was obtained. Infrared absorption spectrum is 3260, 17
30 and 705CTL-1 showed characteristic absorption bands. Example 2 4.0 t (yield: 46%) of crude 2-oxazolidinone was obtained by reacting under the same conditions as in Example 1 except that triethylamine was not used and treating in the same manner.

Example 3 6.17 y of ethanolamine, 22.7 y of synchrohexylcarbodiimide and 100 ml of dioxane in 300 ml
1 autoclave and reacted at 100'C for 2 hours at an initial pressure of carbon dioxide 13k9/Cd.

The reaction was worked up as in Example 1 to give 6.9y of crude 2-oxazolidinone (79% yield based on ethanolamine). Example 4 A mixture consisting of 6.17 ml of ethanolamine, 22.77 ml of synchrohexylcarbodiimide, 11.4 v of triethylamine and 100 ml of acetonitrile was reacted at 100° C. for 2 hours at an initial pressure of carbon dioxide of 36 kg/Crii.

The crude 2-oxazolidinone was treated in the same manner as in Example 1.
．． 77 (yield 77% based on ethanolamine) was obtained. Example 5 A mixture consisting of 6.1f7 ethanolamine, 22.7t1 synchhexylcarbodiimide, 11.67t1 triethylamine and 100ml dimethylformamide was heated at 100°C at an initial pressure of carbon dioxide of 13kg/Crli.
The mixture was allowed to react for 2 hours.

The crude 2-oxazolidinone 5 was prepared in the same manner as in Example 1.
．． 97 (yield 68%) was obtained. Example 6 100 ml of toluene instead of dimethyl formaldehyde
The reaction was carried out in the same manner as in Example 5 to obtain crude 2-oxazolidinone 6.5y (yield 75%).

Example 7 Ethanolamine 6,17, synchhexylcarbodiimide 22.77, pyridine 8.77 (0.11 mol)
and 100 ml of acetonitrile were reacted at 100° C. for 2 hours at an initial pressure of carbon dioxide of 11 k9/Cd.

By treating in the same manner as in Example 1, 6.27 (yield: 71%) of crude 2-oxazolidinone was obtained. Example 8 In Example 7, 13.37 (0.11 mol) of dimethylaniline was used in place of pyridine, and the reaction was carried out under the same conditions except for the reaction to produce 6.37 (yield: 72) of crude 2-oxazolidinone.
%) was obtained.

Example 9 Ethanolamine 6.1y1 Triethylamine 15.2
7 (0.15 mol) and 100 ml of dioxane were placed in a 300 ml four-bottle flask equipped with a stirrer, and carbon dioxide was blown into the flask at room temperature and pressure to saturate the flask.

22.77 ml of carbodiimide and 20 ml of dioxane were added thereto, carbon dioxide was blown into the mixture at a rate of 100 ml per minute, and the mixture was reacted at 98° C. for 2 hours with stirring. By treating as in Example 1, 1.87 2-oxazolidinone was isolated. The melting point of this thing is 88-8
The temperature was 9°C (recrystallized from chloroform). The infrared absorption spectrum of the remaining paste after separating 2-oxazolidinone was 3260 and 1740.
Strong absorption was observed in Me-1.

Example 10 7.5y (0.10 mol) of 1-aminopropan-2-ol, 22.7y of synchlohexylcarbodiimide and 100ml of acetonitrile were placed in a 300ml autoclave, and at an initial pressure of carbon dioxide of 12kg/Cd, 1
The mixture was stirred at 00°C for 2 hours.

After cooling, the reaction mixture was filtered to remove the precipitate (synchrohexyl urea). Evaporate the slurry under reduced pressure and leave 30ml of the residue.
of water was added and heated to 70°C. A small amount of precipitate (synchrohexyl urea) was filtered out. The aqueous solution was cooled with ice water, the paste was removed, and the aqueous solution was evaporated under reduced pressure. When the remaining oil is distilled under reduced pressure, the boiling point is 133-136
9.2 tons of 5-methyl-2-oxazolidinone was obtained at 411 Hg. The yield was 91%. The infrared absorption spectrum of this product is 3300 and 1750c1L-
1 shows absorption. Example 11 2-amino-2-methylprobanol 8.9V (0.1
0 mole), triethylamine 11.4f7 (0.11 mole), synchhexylcarbodiimide 22.7t (0
．． Example 1
By reacting and treating in the same manner as 0, the boiling point is 129
8.5r of 4,4-dimethyl-2-oxazolidinone (yield 74%) was obtained at ~131°C (411Hg).

This substance solidifies when cooled, and its melting point is 51.5-5
It was 4℃. Its infrared absorption spectrum is 3215 and 1764 cm-! showed absorption. Example 12 2-aminobutanol 8.9? (0.10 mol), 11.4 t of triethylamine, 22.7 y of synchhexylcarbodiimide and 100 ml of acetonitrile were reacted and treated in the same manner as in Example 10 to obtain a solution with a boiling point of 1
10.8V (yield 94%) of 5-ethyl-2-oxazolidinone was obtained at 41-144°C (411Hg).

This solidified upon cooling. The melting point is 47-50℃, and the infrared absorption spectrum is 3270 and 1718c7.
It showed absorption at rL-1. Example 13 1-aminobutan-2-ol 8.91, synchhexylcarbodiimide 22.7t and acetonitrile 10
By reacting and treating 01t1 in the same manner as in Example 10, 4-ethyl-2-oxazolidinone 8.8P (yield 77
%) was obtained.

This material was a liquid at room temperature, and its infrared absorption spectrum showed characteristic absorption at 3295 and 1745 cm. Example 14 2-Amino-2-Jylethanol 13.7y (0.
10 mol), triethylamine 11.4y1, synchhexylcarbodiimide 22.6f7 and acetonitrile 100ml were reacted and treated in the same manner as in Example 10.

1.1f7 of crude 5-phenyl-2-oxazolidinone was obtained from the aqueous solution. The water-insoluble paste was distilled under reduced pressure to obtain 10.5 of a semi-solid material with a boiling point of 201-212°C (51!Hg). The crude yield of 5-phenyl-2-oxazolidinone is 71%.

The melting point of the product recrystallized from a mixed solvent of water and ethanol is 7.
At 1-77℃, its infrared absorption spectrum is 3270 and 1
745 (:! Moderate to IL-1, 1720CT!L-
1 showed strong absorption. Example 15 Trans-2-aminocyclohexanol 4.9t (0.0425 mol)
, triethylamine 4.7y1, 8.8 t (0.0425 mol) of synchhexylcarbodiimide and 100 ml of acetonitrile were reacted and treated in the same manner as in Example 10.

Needle crystals of 1.7r were precipitated from the aqueous solution. After dissolving this in chloroform and treating it with activated carbon, the solvent was evaporated.
1.6f of 5-tetramethylene-2-oxazolidinone was obtained. Its infrared absorption spectrum is 3275, 174
3 and 1724 儂-1 showed characteristic absorption. The aqueous solution was evaporated to dryness leaving 3.97 g of solid. Melting point is 73-1
It was 01°C. Infrared absorption spectrum is 3320, 17
It showed absorption at 55 and 1749 cm-1. The total crude yield was 93%. Example 16 7.5 f (0.10 mol) of 2-N-methylaminoethanol, 11.4 f of triethylamine, 22.7 f of synchhexylcarbodiimide and 100 f of acetonitrile
m1 was reacted and treated in the same manner as in Example 10.

Water was distilled off from the aqueous solution, and the residue was distilled under reduced pressure to obtain 4.7f of liquid with a boiling point of 94.5-97°C (4 mercury of Hg). Being N-methyl-2-oxazolidinone means that
This was confirmed because the infrared absorption spectrum showed absorption at 3300 and 1742 儂-1. Crude yield is 46%.
Example 17 2-N-ethylaminoethanol 8.97 (0.10 mol), triethylamine 11.4f, dicyclo-xylcarbodiimide 22.77m and acetonitrile 100m
1 was reacted and treated in the same manner as in Example 10.

An oily product of 1.2y from the aqueous solution and 5.37y from the water-insoluble oil was obtained by vacuum distillation. Both boiling points are 109
The temperature was ~115°C (5m7!LHg). N-ethyl-
The crude yield of 2-oxazolidinone is 57%.

Its infrared absorption spectrum is 3485 and 1746C! T.L.
-1 showed absorption. Example 18 N-n-butylaminoethanol 11.7y (0.10
mol), triethylamine 11.4V1 synchhexylcarbodiimide 22.77 and acetonitrile 100
m1 was reacted and treated as in Example 10.

Claims (1)

[Claims] 1 General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, R_1, R_2, R_3 and R_4 are the same or different, and each is a hydrogen atom, an alkyl group, or an aryl group, or Alternatively, any two of them can be linked to form an alkylene group, and R_5 is a hydrogen atom or an alkyl group). A method for producing a 2-oxazolidinone compound represented by the general formula ▲Mathematical formula, chemical formula, table, etc.▼ (R_1, R_2, R_3, R_4 and R_5 in the formula have the same meanings as above), which is characterized by a reaction . 2. The manufacturing method according to claim 1, which is carried out in the presence of a tertiary amine.