HU206668B - Process for producing quaternary ammonium-compounds - Google Patents

Abstract

Quat. ammoniumm cpds. of general formula (1) - where at least two h gps. are ethyl or methyl and the remainings gp.(s) is (ore) 3-18C alkyl as aralkyl ops. on condition that where three of the 2 gps are methyl gas, then the fourth has to be dissimilar and that X is an anion - are prepd. from amines of formula (11) - where one of R1,R2 and R3 gps is H, the remaining two gps. are independently of each other hydroplu atmos, or 3-18C alkyl or aralkyl gps. - and from methyl - or ethyl chloride in the gp. medicine, in the prescence of a base at 60 deg. C at 0'1 -1.0 MPa pressure. Chloride ions in position of x-in (1) may be changed for another anion. Base used in this reaction is a calcium-hydroxide suspn. or a source of calcium-hydroxide

Description

The present invention relates to a process for the preparation of quaternary ammonium compounds of formula I wherein at least two of the R groups are methyl or ethyl, and the remaining group (s) is (C3-C18) alkyl or phenyl (1-3C). A C4 alkyl) group, provided that when three of the R groups are methyl, the fourth may be different from the methyl group only, and

X represents anion.

The compounds of formula (I) are mainly used in the chemical industry as phase transfer catalysts and cationic surfactants.

Compounds of formula I wherein two or three of the R groups are methyl or ethyl and the remaining R group (s) represent (C 3 -C 18) alkyl or phenyl (C 1 -C 4) alkyl (a), by preparing the appropriate primary or secondary amine containing one or two C3-C18 alkyl or phenyl (C1-C4 alkyl) groups with dimethyl sulfate, diethyl sulfate, methyl bromide, ethyl with bromide, methyl iodide or ethyl iodide, or with trimethylamine or triethylamine

They are quaternized with C3-C8 alkyl or aralkyl halides and, if desired, the X ^- anion of the compound of formula (I) obtained is exchanged for another anion (Lempert K, Organic Chemistry, pp. 402-406 [Technical Journal, Budapest, 1976]). . The disadvantage of the process is that the quaternizing reagents used are relatively inaccessible, expensive materials.

Of the readily available methyl chloride and ethyl chloride, which are often readily available as chemical by-products or wastes, only methyl chloride has been used so far for the production of tetramethylammonium chloride outside the scope of the compounds of formula I (Hungarian Patent No. 199397). According to the disclosed solution, methyl chloride is added to an aqueous solution of ammonia at a temperature of 50-140 ° C and a pressure of 0.1-1.0 MPa, and sodium hydroxide is added in portions or continuously. Continuous addition of the base is preferred herein. However, this causes serious operational problems due to the overpressure in the reactor.

In our experiments, it has been found that the process described in Hungarian Patent Application No. 199397 can be made suitable for the preparation of compounds of formula (I) and that the operational difficulties of continuous addition of the base can be completely eliminated by using calcium hydroxide or hydroxide as the base.

Calcium hydroxide is known to be poorly soluble in water and its solubility in water decreases rapidly with increasing temperature. At 100 ° C (average reaction temperature), only 0.077 g of calcium hydroxide is dissolved in 100 g of water. During the reaction, calcium hydroxide is formed into calcium chloride, which, as a high ionic strength and water-binding agent, further decreases the solubility and dissolution rate of calcium hydroxide. In view of these facts, it was to be expected that calcium hydroxide would not be used as a base in the reaction, since the amount of calcium hydroxide dissolved in the reaction medium, thus available for the binding of hydrochloric acid, was only a fraction of the required amount of alkali. Thus, we had to expect that the reaction would stop after a short time and that the desired products were formed in very low yields.

In view of the foregoing, it is extremely surprising that the compounds of formula (I) can be prepared in a simple manner in a theoretical manner in the presence of calcium hydroxide suspended in the reaction medium. The exact explanation of this phenomenon is unknown, but it is believed that this is due to the unexpected dissolution mediation of the methylated and ethylated amines formed in the reaction.

The present invention therefore relates to a process for the preparation of quaternary ammonium compounds of formula (I) wherein R and X are as defined above - Amines of formula (II) wherein R 1, R ₂ and R ₃ are as defined above - in an aqueous medium, in the presence of a base, at 60-130 ° C, at a pressure of 0.1-1.0 MPa, with methyl chloride or ethyl chloride, and if desired, the other chloride of the compound of formula I containing X by anion exchange. According to the invention, the base used is calcium hydroxide or a source of calcium hydroxide suspended in the reaction medium.

Mixtures of calcium hydroxide containing materials (for example, lime hydrate, which usually contains about 20% by weight of calcium carbonate in addition to calcium hydroxide), or substances which are converted to calcium hydroxide by water (such as calcium oxide) may be used as the source of calcium hydroxide. The calcium hydroxide or source of calcium hydroxide may be added in the form of a powder or an aqueous suspension. At least the stoichiometric amount of calcium hydroxide is added to the reaction mixture. The upper limit of the amount of calcium hydroxide is not critical and is essentially determined only by the miscibility of the reaction mixture.

The reaction is carried out in an aqueous medium. By "aqueous medium" is meant a mixture of water or water and a water-soluble organic liquid, such as a lower alcohol, which is inert to the reaction.

The reaction is carried out by charging the amine of formula II and the reaction medium into a gas-liquid contact apparatus, adding calcium hydroxide or a source of calcium hydroxide, and closing the apparatus with methyl chloride or ethyl chloride gas under stirring and heating. into the device. The molar amount of gas required can be injected simultaneously, but at the required temperature of 60-130 ° C, the pressure increases significantly. Therefore, it is preferable to introduce the methyl chloride or ethyl chloride gas into the apparatus in portions or continuously. The end of the reaction is clearly indicated by the fact that more methyl chloride or ethyl chloride is no longer absorbed in the reaction mixture.

In a preferred embodiment of the process of the invention, ammonia is present in an aqueous solution of 5 to 15% by weight,

Tetraethylammonium chloride was reacted with ethyl chloride in the presence of 1.5-2 moles of calcium hydroxide in the presence of 1.5-2 moles of calcium hydroxide at 100-110 ° C and 0.5-0.6 MPa.

In another preferred embodiment, a mixture of N-tetradecylamine and N-dodecylamine in ethanol or isopropanol containing 30-50% by volume of water in the presence of 1-1.5 moles of calcium hydroxide per mole of amine at 100-110 ° C, Reaction with methyl chloride at 4-0.6 MPa to give the corresponding N-alkyltrimethylammonium chloride mixture.

In another preferred embodiment, N-dodecyl-N-benzylamine is treated with N-dodecyl in aqueous isopropanol in the presence of 1 mole of calcium hydroxide per mole of calcium hydroxide at about 100 ° C and 0.5-0.7 MPa pressure. N-benzyl-N, N-dimethylammonium chloride (known as benzalkonium chloride disinfectant) is prepared.

The invention is further illustrated by the following non-limiting Examples.

Example 1

A gas-liquid contact apparatus is charged with 1000 ml of aqueous ammonia solution containing 3 moles of ammonia and 6 moles of calcium hydroxide (80% by weight of calcium hydroxide and 20% by weight of calcium carbonate) corresponding to calcium hydroxide. Ethyl chloride was passed at 110 ° C and 0.6 MPa. After consuming 14 moles of ethyl chloride, the reaction mixture was cooled, the solid filtered and the filtrate evaporated to give water. The residue was recrystallized from isopropanol. Crystalline tetraethylammonium chloride was obtained in 70% yield.

Example 2

A 1 molar mixture of N-dodecylamine and N-tetradecylamine in a 2: 1 molar ratio is dissolved in a mixture of 700 ml of isopropanol and 300 ml of water. To the solution is added 1.5 mol of calcium hydroxide in an amount of lime hydrate, and the amine mixture is reacted with methyl chloride under the conditions and apparatus of Example 1. The reaction time is 4-10 hours, depending on the contact intensity; the end point is detected by determination of the chloride ion. The reaction mixture is a

Work up as described in Example 1 to give a mixture of N-dodecyl and N-tetradecyltrimethylammonium chloride in 90% yield. The product mixture was found to be more than 98% pure by high pressure liquid chromatography.

Example 3

A 1 M mole mixture of N-dodecyl-N-benzylamine and N-tetradecyl-N-benzylamine in a 2: 1 molar ratio is dissolved in 1 L of 10% water in isopropanol, and 1 mol of calcium hydroxide is added to the solution. conditions and apparatus with methyl chloride. The reaction mixture was worked up as described in Example 1 to give benzalkonium chloride in 90% yield.

Claims (2)

PATENT CLAIMS A process for the preparation of quaternary ammonium compounds of formula I wherein at least two of the R groups are methyl or ethyl, and the remaining group (s) is (C3-C18) alkyl or phenyl (1-4). is (C 1 -C 4) alkyl, provided that when three of R are methyl, the fourth may be different from methyl, and X ^- represents an anion) amines of the general formula - wherein R, R ₂ and R ₃ are a hydrogen atom and the remaining two groups are each independently hydrogen or Represents a C 3 -C 18 alkyl or phenyl (C 1 -C 4 alkyl) group by reaction with methyl chloride or ethyl chloride in an aqueous medium in the presence of a base at a temperature of 60 to 130 ° C at a pressure of 0.1 to 1.0 MPa and optionally exchanging the chloride ion of the resulting compound of formula (I) wherein X 'is chloride with another anion, characterized in that the base used is calcium hydroxide or a source of calcium hydroxide suspended in the reaction medium. Process according to claim 1, characterized in that the calcium hydroxide source is lime hydrate.