DE961086C - Process for the preparation of oxazolidone- (2) - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

ISSUED APRIL 4, 1957

GERMAN PATENT OFFICE

PATENT LETTERING

CLASS 12p GROUP 3 INTERNAT. CLASS C07d

S 32274 IVbI is p

Marcel-Jean Viard, Bois-Colombes, Seine (France) has been named as the inventor

Societe Anonyme des Manufactures des Glaces et Produits Chimiques de Saint Gobain, Chauny & Cirey, Paris

Process for the preparation of oxazolidone- (2)

Patented in the territory of the Federal Republic of Germany on February 21, 1953 Patent application published October 11, 1956

Patent granted on March 21, 1957 The priority of the application in France of February 25, 1952 has been claimed

The invention is a process for the preparation of oxazolidonen- (2) of the general formula

C .H.2 -

CCK

in which R is a hydrogen atom or an aliphatic, aromatic or aliphatic-aromatic hydrocarbon radical means which can also be substituted.

It has already been proposed to make Oxazolidone- (2) by the action of silver carbonate or sodium carbonate to produce bromoethylamine bromohydrate [cf. Gabriel, “Reports of the German Chemical Gesellschaft ", Vol. 30, p. 2494 (1897), and Vol. 38, p. 2410 (1905)]. More recently it is suggested been to produce Oxazolidone- ^) by the action of an alkyl carbonate on amino alcohols. These known processes require the use of very expensive starting materials and are unsatisfactory Exploit.

In contrast, the method according to the invention enables one possible on an industrial scale Manufacture of the oxazolidones identified above.

This process consists in the ammonium or alkali bicarbonate being converted to alkali salts of the sulfuric acid ester the substituted or unsubstituted

Ethanolamines are brought into action at a maximum of yo °.

The reaction can be viewed as proceeding in two successive phases:

P TT PTT

VvXl ₂ VyXl ₉

jj + NaHCO ₃ >

SO ₄ NHR

i. Fixation of the alkali bicarbonate on the amine group of the alkali salt of the ethanolamine sulfuric acid ester to form an alkali salt of a substituted Carbamic acid and a water molecule:

+ H ₂ O

SO ₄ Na RN-COONa

(I)

2. Splitting off of a molecule from neutral alkali | Formation of an oxazolidone (2): 10 sulfate and ring formation of the rest of the molecule under:

CH,

-CH ₉

SO ₄ Na ₂ C Hg - C H2 χ

:NO

(Π)

SO ₄ Na RN-COONa

CO '

The course of this reaction phase is determined by a means of an alkali metal hydroxide or bicar

Increases in temperature favored.

The alkali salt of the ethanolamine sulfuric acid ester can be prepared in any suitable manner, preferably by neutralizing the acidic ester

CH ₉

-CH ₂

+ CO ₃ Na ₂

SO ₄ H NHR

so that reactions (I) and (II) of the new process can follow immediately. Neutralization by an alkali carbonate bonats.

In the course of neutralization by an alkali carbonate the alkali salt of the ethanolamine sulfuric acid ester and an alkali bicarbonate are formed at the same time according to the reaction

CHR-CH ₂

j + CO ₃ NaH (III)

SO ₄ NHR

requires the application of 2 molecules of bicarbonate to achieve the same result. In this Trap results in the following overall equation:

CH ₉

SO, H

-CH ₂
NHR

+ 2CO ₃ NaK = 5O ₄ Na ₂ + CO ₂ + 2H ₂ O + CH ₂ -

O CO '

(IV)

In practice, the oxazolidone- (2) from the acid sulfuric acid esters of ethanolamine easily by heating this body with the alkali carbonate or bicarbonate in the required proportions, d. H. of 1 molecule of neutral Alkali carbonate to 1 molecule of sulfuric acid ester or 2 molecules of alkali bicarbonate to 1 molecule Sulfuric acid esters in aqueous solution at temperatures between 40 and 70 °. The heating must take place gradually to prevent the escape of carbonic acid (except for the amounts normally used in the Reaction (IV) arising) to prevent. If one were to heat too harshly, especially with sour ones, esters derived from amines in which the formation of the carbonate takes place relatively slowly, see above a part of the bicarbonate could dissociate and the neutral carbonate arise, which no longer with the Alkali salt of the ester in the sense of reaction (I) can react, since in this case the bicarbonate is required. This would result in a reduced yield.

In order to avoid these difficulties, it is when the alkali salt of the sulfuric acid ester in the same Operation by neutralizing the acidic sulfuric acid ester with a neutral carbonate or a Alkali hydroxide is formed, expediently to add a small amount of bicarbonate to the loss to compensate for this, which can occur in the course of reaction (III).

The duration of the reactions to the. Formation of the oxazolidones according to the invention depends on the starting materials varies and can vary between 12 and 24 hours.

The reaction product is an aqueous liquid from which alkali sulfate crystals precipitate. which are separated off by suction filtration and washed with a saturated solution of alkali metal sulfate will. The filtrate and wash waters are combined, and preferably under vacuum evaporated. The dry product obtained, which still contains alkali metal sulfate, is, preferably in the Heat, through solvents for the Oxazolidone- ^), in which the alkali sulfates are insoluble, such as. B. Alcohol, gasoline, dichloroethane or dichloroethylene, extracted.

If work is carried out without observing appropriate precautionary measures, more or less large proportions of ethanolamines and ureas are formed, which (practically in the the same degree of solubility) in the solvents used as the Oxazolidone- ^), so that in this In the case of viscous, non-crystallizable products, the separation of which is very difficult. In this context it should be noted that the solvent, if it is unsubstituted Oxazolidon- (2) is particularly suitable dichloroethylene, because it is the compound mentioned in the heat dissolves very well, while the urea remains insoluble.

The crude oxazolidones (2) obtained by evaporation of the solvent can be obtained by crystallization or fractional distillation under very high vacuum. The choice of which to use for the response The alkali salt of the sulfuric acid ester of ethanolamine is not without importance. The potassium salts have the advantage over the other alkali salts that they are particularly soluble and it consequently it is possible to work in a concentrated solution. Ammonium salts also turn out to be suitable. In this case, it is convenient and economical to use the ethanolamine sulfuric acid ester dissolved in an ammonia solution and the solution thus prepared is then passed through a stream of carbon dioxide becomes saturated.

Below are a number of embodiments of the method according to the invention given.

example 1

141 g (1 mol) of ethanolamine sulfuric acid ester dissolved in 200 ecm of water and 106 ecm of a 37.8% sodium hydroxide solution are added while maintaining a Mixed temperature from 10 to 12 °.

90 g of sodium bicarbonate are added to the clear solution of the sodium salt of the ethanolamine sulfuric acid ester obtained. Then 8 hours heated to 40 ⁰ and 10 to 12 hours at 70 ^0th After evaporation to dryness, the residue is taken up in dichloroethane and the product dissolved in the dichloroethane crystallizes out, 79 g (90% of theory) of oxazolidone- (2) are obtained. 35

Example 2 *

141 g of ethanolamine sulfuric acid ester are mixed with 350 g of an ammonia solution of 22%. The mixture is heated to 50 ⁰ and a stream of CO ₂ is passed, has been achieved g until a weight increase of about 55 to 60th The mass is then kept at a temperature of 50 ° for 10 hours and a gentle stream of CO _{2 is} introduced during this time. It is then heated to 60 ° for 4 hours and then to 70 ° for 4 hours. The reaction mixture is worked up according to Example 1 using dichloroethylene as the solvent and that

Thus obtained oxazolidone- (2) in 92% yield.

Example 3

In a vessel equipped with a stirrer are placed at room temperature:

Monoethanolamine sulfuric acid ester 141 g (1 mol)

Potassium carbonate (98%) 141 g (1 mol)

Water 200 g

The result is a clear solution, that is slowly heated to 50 ^0, it being ensured that no carbon dioxide is released. This temperature of the reaction mass (50 °) is maintained for 4 hours. Now, 14 g of potassium bicarbonate are added and kept for another 12 hours at 50 ^0th

After cooling, the potassium sulfate crystallizes out. This is sucked off and with a washed small amount of saturated potassium sulfate solution. The filtrate and wash water are combined and evaporated to dryness in vacuo.

The result is a crystalline mass which is extracted with dichloroethane while warm.

By cooling the dichloroethane solution, 83 g of oxazolidone- (2) melting at 92 ° are obtained. the The yield is 94% of theory.

Example 4

185 g of sodium bicarbonate, 250 g of water and 141 g of ethanolamine sulfuric acid ester are placed in a container equipped with a stirrer and a discharge pipe. There is immediately a violent development of CO ₂ , which ceases after ι to 2 hours. Then, it is gradually heated for about 15 hours up to 50 ⁰ and then for 4 to 5 hours to 70 ^0th The reaction mixture is worked up according to Example 1 using alcohol as the solvent. The yield of oxazolidone- (2) is 90%.

Example 5

141 g of ethanolamine sulfuric acid ester are introduced into a mixture of 113 g of sodium carbonate and 250 ecm of water at room temperature. The reaction mixture is left at rest for 3 or 4 hours, after which 15 g of sodium bicarbonate are added. Now, 10 hours heated to 40 ⁰ and then 6 to 7 hours at 70 ⁰ approximately. After cooling, the reaction mixture is worked up according to Example 1 by suction filtering off the alkali metal sulfate, evaporating the aqueous solution in vacuo and taking up the residue in a solvent. The result is a yield of about 90% of oxazolidone- (2).

Example 6

A solution of 150 g of sodium carbonate in 200 g of water is heated to 50 ° and slowly during about 3 hours with stirring a solution of 155 g (1 mol) of methylethanolamine sulfuric acid ester

HO-SO ₂ -O- CH ₅ , - CH ₉ - NH -r- CH,

registered in 150 g of water. The mass is then kept at one temperature for about 15 for 20 hours held at 50 °. The result is a liquid containing crystals in suspension, which is suction filtered will. The filtered liquid is evaporated under vacuum. The sucked-off crystals will be in turn washed with alcohol and the alcoholic liquid to the evaporation residue of the aqueous Liquid added. Now the mix is

evaporated to dryness and the residue taken up by alcohol, whereby the N-methyloxazolidone- (2) dissolved and a further amount of sodium salt is separated off. The obtained N-methyloxazolidone- (2) has the following constitutional formula:

CH ₂ - CH ₂ \

I) n-ch ₃

- CO

Example η

To 185 g (1 mol) of monosulfuric acid ester of Diethanolamine from the formula

OHCH ₂ -CH ₂ -NH-CH ₂ Ch ₂ -SO ₄ H

255 g of an ammonia solution of 22% are slowly added, which corresponds to 3 molecules of ammonia. 72 g of carbonic acid are introduced into the solution obtained. The mixture is then heated to 40 ° and this temperature is maintained for 15 to 18 hours. After cooling, the ammonium sulfate is separated off by suction filtration and washed with alcohol. The filtrate and the washing water are evaporated to dryness. There are 136 g of crude N-ethanoloxazolidone- (2) in the form of a slightly brownish, viscous liquid which still contains small amounts of sulfate. This crude product can be used as it is for the later reactions. It is difficult to purify by distillation because it has a tendency to decompose and resinify. However, a too long exposure to the heat to be avoided, it may contain minor amounts distill at 170 ⁰ in 6o ° / ₀ yield under 0.5 mm mercury.

Example 8 ¹ J ₂ mol) sulfuric acid ester of phenyl

108.5 g
ethanolamine from formula

HO · SO ₂ - O · CH ₂ -CH ₂ -NH-C ₆ - H ₅ ,

which are dissolved in 200 ecm of water are converted into the sodium salt by the gradual action of 20 g of caustic soda containing sodium hydroxide solution. 50 g of sodium bicarbonate are added to the solution thus obtained. The mixture is heated for 2 to 3 hours at 45 ⁰ and then for 20 hours at 60 °. A precipitate forms, which is sucked off. The liquid is evaporated to dryness and the residue extracted with alcohol. Evaporation of the alcohol gives 70 g of crude crystallized N-phenyloxazolidone- (2) of a slightly greenish color and a melting point of 117 °. Recrystallization and discoloration with animal charcoal give 65 g of white crystals with a melting point of 123 °. The obtained N-phenyloxazolidone- (2) has the following constitutional formula:

C xio -

) NC ⁶ H ⁵

co-

Claims (3)

PATENT CLAIMS: i. Process for the preparation of oxazolidones (2), characterized in that in aqueous solution at moderate temperatures of at most 70 ⁰ alkali or ammonium bicarbonates on alkali or ammonium salts of sulfuric acid esters of amino alcohols of the general formula RNHCH ₂ CH ₂ SO ₄ M, in which M is the metal or the ammonium group and R is a hydrogen atom or an aliphatic Aryl or alkaryl radicals, which can also be substituted, represents, for 12 to 24 hours for Brought to the effect that the Oxazolidone- (2) and the by-products of the reaction by suction filtration of the aqueous liquid from the alkali sulfate crystals, evaporation of the aqueous liquid to dryness and extraction of the residue by a solvent for Oxazolidone- ^) separated and from this solution the Oxazolidone- ^) by crystallization or distillation can be obtained in a pure state under vacuum. 2. Embodiment of the method according to claim i, characterized in that in the presence a small excess of alkali metal bicarbonate worked beyond the theoretical amount will. 3. The method according to claim 1 to 3, characterized in that ammonium bicarbonate is used is, which in the reaction mass by successive addition of ammonia solution and carbonic acid is formed. Publications considered: Ber. German former Ges., Vol. 30, 2494 and 2495 (1887); 38: 2410 (1905);
U.S. Patent No. 2,437,390. © «09 657/457 10.56 (609 853 3.57