NL7904648A - PROCESS FOR PREPARING BIS (N, N-DIALKYLAMINO) ALKYL ETHERS. - Google Patents

Description

% v.o. 7816 _________________

Union Carbide Corporation New York

United States of America

Process for preparing bis (N, Ν-dialkylamino) alkyl ethers

The invention relates to a process to prepare bis- (N, N-dialkylamino) alkyl ethers of the formula (RgNR ') 2 where R is a methyl or ethyl group and R' is a divalent alkylene group containing 2-3 carbon represent atoms. These ethers are useful as catalysts in the preparation of polyurethanes, especially polyurethane foam. It is known that bis- [3- (II, N-dimethyl-amino) alkyl] ethers including the. are technically important 1 bis- [2- (Ν, Ν-dimethylamino) ethyl] ether (BDMEE) capable catalysts in the preparation of polyurethanes, especially in the preparation of soft polyurethane foam. Thus, the preparation of polyurethane foam by reaction of an organic isocyanate with a polyol in the presence of this catalyst is described in U.S. Patent 3,330,782.

Various methods of preparation for bis- [β- (N, N, -dimethylamino) -15 ethyl] ethers including BDMEE are known. One of those methods uses di- (2-chloroethyl) ether as the starting material (U.S. Pat. Nos. 3: 00,157 and 3: 26,072). However, the use of di - (2-chloroethyl) ether has several drawbacks, including a) the need to use relatively expensive corrosion resistant equipment due to the presence of chlorides in the reaction mixture and b) environmental problems associated with the chlorides obtained as a by-product and c) the relatively high price and the low availability of di- (2-chloroethyl) ethers.

In another process for the preparation of bis - [- (id, IT-dimethylamino) alkyl] ethers, a 3- (N, N-dimethylamino) alkanol, 7904648 r * 2 is a β- (Ν, Ν-dimethylamino) alkyl chloride and an alkali metal hydroxide react with each other using a modified Williamson synthesis as described in U.S. Pat. No. 3,980,675. However, this method of preparation also has several drawbacks including 5 a) multiple steps in which solids must be handled, b ) work must be discontinuous, c) there are environmental problems associated with the sodium chloride formed as a by-product and d) one of the starting materials, namely 2-dimethylaminoethyl chloride, which is used in the preparation of BDMEE is an unstable liquid and, in addition, a blistering agent, which must be handled with special precautions.

Another method for the preparation of BDMEE comprises etching 15 of trimethylamine with 2- [2- (H, IT-dimethylamino) ethoxy] ethanol, in the presence of. a nickel catalyst under elevated pressure (U.S. Pat. No. 3,957,875). In this process it is necessary to use very high pressure, while the yield of the product leaves much to be desired.

There is therefore a need for a process for the preparation of bis- (N, N-dialkylamino) alkyl ethers, including BDMEE, which does not have the above drawbacks.

The object of the invention is to provide a process for the preparation of bis- (H, N-dialkylamino) alkyl ethers, including BDMEE, starting from relatively inexpensive and readily available starting materials, in which a high yield is obtained, while the process is carried out essentially in one reaction vessel, so that no material transport is required, while working in a liquid phase, so that no solids need to be handled.

According to the invention, bis- (N, E-dialkylamino) alkyl ethers of the general formula (R 1 'R') ^ 0 are prepared, in which R is a methyl or ethyl group and R 'is a divalent alkylene group with 2-3 carbon atoms which is characterized in that a) a sodium alkoxide of the formula RgRR 'QJTa is reacted with 0.1-0.8 and preferably with 0.05-0.55 moles of SO2 vapor per mole of sodium alkoxide at a temperature below 90 ° C and preferably at 7904648 m 3.

3 20-50 ° C in the presence of I. a ΙΪ, ΙΙ-dialkylaminoalkanol of the formula EgNE'OH in a molar ratio of the sodium alkoxide to the said ethanol between 1: 0.5 and 1: 3 and optionally 5 II. an organic redundant, preferably in a quantity of 10-50% by weight, based on the alkoxide and the said ethanol, under rorming of a first reaction mixture, b) re-heating the first reaction mixture for sufficient time to obtain bis- (Η, Η -dialkylamino) alkyl ether and recovering c) this product.

In another embodiment of the invention, the potassium alkoxide is used instead of the sodium alkoxide mentioned above.

The reaction according to the invention proceeds in two stages, which can be ignored as rolgt.

15 Stage 1

BgHR'QlSra + SO3 1 90 C HHHB'OSO ^ a stage 2 lySROBTA + B ^ IROSOS JTAa ^ (Hm% 0 + NaSO.

20 ώ ώ where B is a methyl or ethyl group and R 'is a divalent alkylene group with 2-3 carbon atoms. Although the process can also be continuously stirred according to the process, it is still preferably batchwise stirred in one reactor.

The starting material sodium dialkylaminoalkoxide can be prepared by reacting sodium hydroxide with H, H-dialkylalkanolamine at about 100 ° C and then distilling off the reformed water. The sodium dialkylaminoalkoxide can be prepared in an instant by dissolving sodium metal in ϊΓ, Η-dialkylalkanolamine. Useful sodium dialkylaminoalkoxides include sodium-2-N, H-dimethylamino-30 ethoxide, sodium-1-N, H-dimethylamino-2-propoxide, sodium-2-IT, H-dimethylamino-1-propoxide, sodium-2 -H, H-diethylaminoethoxide, sodium-1 -IJ, H-diethylamino-2-propoxide and sodium-2-H, H-diethylamino-1-propoxide. In a completely analogous manner one can prepare the corresponding potassium alkoxides. Suitable potassium dialkylaminoalkoxides are the potassium analogues of the sodium-boron compounds mentioned above, such as potassium-2-Η, ΓΓ-dimethylaminoethoxide and potassium-1-H, H-dimethylamino-2-propoxide.

7904648 4 * k

The sodium dialkylaminoalkoxide is used, dissolved in the corresponding dialkylaminoalkanol in the reaction mixture.

The dialkylaminoalkanol serves as a solvent for the sodium alkoxide. For example, sodium 2-N, N-diethylaminoethoxide dissolved in 5 N, N-diethylethanolamine is used; sodium-2-N, N-dimethylaminoethoxide is used dissolved in N, N-dimethylethanolamine and sodium-3-N, N-dimethylamino-1-propoxide is used, dissolved in 3-N, N-dimethyl-amino-1-propanol . The dialkylaminoalkanol is used to ensure that the sodium alkoxide remains dissolved in the reaction mixture during step 1 of the reaction and does not crystallize.

The molar ratio of the sodium dialkylaminoalkoxide to the corresponding dialkylaminoalkanol is not critical and is usually between 1: 0.5 and 1: 3 and preferably between 1: 1 and 1: 2. The lower the temperature. the more dialkylaminoalkanol is needed to keep the alkoxide in solution. However, as the temperature during step 1 is closer to 90 °, the ratio of alkanol can. to alkoxide smaller and even less than 1: 1. The reaction according to the invention can also be carried out with the potassium alkoxide instead of the sodium alkoxide.

The organic diluent which can be used according to the invention can have three functions. First of all, it serves as. diluent. for the sodium dialkylaminoalkoxide, thereby moderating the rate of reaction between the sodium dialkylaminoalkoxide and SO 2 and reducing the chance of carbonization during that reaction. In the second sites, it serves as a diluent and co-solvent (along with the dialkylaminoalkanol) for the sodium dialkylaminoalkoxide, thereby preventing crystallization of the sodium dialkylaminoalkoxide during step 1. At a high ratio of dialkylaminoalkanol alkoxide, a large amount of organic diluent can be used without causing precipitation of the alkoxide present, the limit being determined only by economic considerations. Third, during the recovery of the bis- (N, N-dialkyl-amino) alkyl ether, the Solvent can be used as a high boiling residue. Suitable diluents must simultaneously satisfy the condition a) not reacting with SO 2 in the reaction mixture and b) boiling point 7904648 * 5 rotate at least 90 ° C and preferably at least 100 ° C at atmospheric temperature. Such a boiling point causes the reaction to end within a conmercially acceptable period because the boiling temperature and hence the reaction temperature is directly related to the boiling point of the diluent. Provided that the boiling point of the diluent is at least about 10 ° higher than the boiling point of the bis-ether product, this solvent can simultaneously serve as a high boiling residue during finning of the bis-ethers. For use as a high boiling residue, the diluent can be added at any stage before distillation is performed.

Useful diluents include straight chain hydrocarbons such as W-heptane, N-octane and W-tetradecane. straight chain, branched chain hydrocarbons or mixtures thereof with 7-30 carbon atoms / molecule and ethers such as tetrahydrofuran, dioxane and the mono and dimethyl ether of glycol. Toluene was found to be unsuitable as a diluent because it reacts easily with it. SO ^ »

The amount of the diluent used according to the invention can vary widely depending on the starting materials used and on the diluent to be selected and on the temperature. Usually, an amount of 0-600 wt.%, And preferably 10-50 wt.% Of the diluent is used, based on the amount of sodium W, N-dialkylaminoalkoxide and N, dial-dialkylaminoalkanol used in the mixture. When the selected reaction temperature is in the upper part of the range 20-50 ° C, an improved solubility of the alkoxide is thus obtained, without the need to use much organic diluent or an extra amount of dialkyl amino alkoxide. to add. When the N, f-dialkyl-ananolalkanol 30 is used in a relatively large amount (i.e. 2.5-3 mol / mol sodium alkoxide), the reaction can also be carried out without using a diluent.

The sulfur trioxide used in accordance with the invention is supplied as vapor in an amount of 0.25-0.60 and preferably 35.0-0.55 mole SO2 -delta per mole sodium-W, Ν-dialkylaminoalkoxide.

When introducing the sulfur trioxide vapor into the mixture, care should be taken to avoid a) a high local heat generation leading to degradation and side reactions and b) cm to avoid blockages at the point where sulfur trioxide is supplied.

Preferably, the sulfur trioxide is mixed with an inert diluent, such as nitrogen or argon, before it is introduced into the reaction mixture.

The reaction according to the invention is preferably carried out with an apparatus such as that described in Example 1 below. The design of the gas scrubbing column and the location of the sulfur trioxide feed tube are important considerations when using a. such device. The gas wash column must be self-cleaning, i.e., any solids formed which separate from the reaction mixture must be flushed through the liquid in the reaction mixture to the reactor. Useful designs for a wash column include downwardly pointing spiral projections, a "disk and ring" arrangement, as used in the stripping section of. an artisan stripper, one. cross-flow setup ,. wherein perforated plates are arranged horizontally in a cylindrical column and a number of flat plates, which are arranged either horizontally or inclined in a descending spiral shape. On the other hand, formation of solids in the reaction mixture can cause clogging of the wash column when using conventional packing materials such as Raschig rings or glass beads. The sulfur trioxide feed line in the above equipment should be above the surface of the liquid mixture in the reactor to prevent the line from being clogged by any solids formed.

The reaction time limits of the process of the invention are not critical and may vary within wide limits. Since step 1 of the reaction proceeds rapidly when SO 2 is introduced into the reactor, the duration of step 1 is limited only by the rate at which SO 2 can be supplied while keeping the reaction temperature constant within those set limits. Typically, a suitable duration for step 1 is 0.5-10 hours, and preferably 0.5-10 hours.

7904648 τ

In step 2 of the reaction, the reaction mixture is heated, preferably at 100-120 ° C for sufficient time to form the desired bis (Η, ΪΓ-dialkylamino) alkyl ether. The time required for step 2 is usually 1.5-12 hours and preferably 1.5-5 hours.

The process according to the invention is usually carried out under atmospheric pressure, although an increased or reduced pressure can also be used if desired.

The recovery of the bis (li, K-dialkylamino) alkyl ether can be carried out by any known method. Preferably, at the end of the reactions, a. distillation applied. In that case, all 10 operations including recovery of the product may commence directly. the reactor.

As mentioned, the process according to the invention can be used in the preparation of bis (ff, β-dialkylamino) alkyl ethers of the type described above. Examples of such ethers are: bis- [β (H, H-dimethylamino) ethyl] ethers, bis- [β - (H, H-dimethylamino) -1 -15 methyl ethyl] ethers, bis— [β- (H, ff -dimethylamino) propyl] ethers, bis- [3-F, IT-di methylamino) propyl] ethers, bis- [β- (3tf, ίΓ-diethylamino) -ethyl] ethers, bis- [3 - (ff, ff- diethylamino) -1-methyl ethyl] ether bis- [β- (ff, ff-diethylamino) propyl] ether. Preferably, BDMEE is prepared. Other bis-ethers containing tertiary amines and not covered by the above formula and yet. can be prepared, according to the method of the invention, the compounds of formulas 1 and 2 of the. formula sheet. Such ethers are also useful as a catalyst in the preparation of polyurethane foam.

The invention is illustrated by the following examples.

In the examples below, the following abbreviations are used: 7904648 f - 8 BDMEE bis [2- (N, N-dimethylamino) ethyl] ether

Diluent 1 Mixture of alkanes with the following composition:

Wt. %

Normal alkane C12 0.02 5 "" C13 0.1 * 9 "" C1U 66.95, T "C15 31.79" "C16 0.53

Isoalkanes 0.22 10 Diluent diluent 2 n-heptane

Diluent 3 n-octane% wt. #

Example Γ

Preparation of BDMEE. with diluent t 15 The apparatus consisted of a 3 L reactor with four necks equipped with. a heating jacket and a drain tap in the bottom, a washing column, a mechanical stirrer and thermometer and a gas inlet pipe. The outlet in the bottom was connected to the pump inlet. The pump outlet was. connected by a tube 20 with heating forged to the upper end of the washing column.

The washing column consisted of one. glass column, which was provided with spiral-placed indentations, which pointed downwards. A reflux condenser, which was connected to a source of dry nitrogen, was placed on top of the wash column. The gas supply tube was. connected to a source of sulfur dioxide, which was mixed with nitrogen.

The synthesis of the BDMEE was performed as follows:

2.69 moles of sodium 2- (N, N-dimethylamino) ethoxide and 25 moles of N, N-dimethylethanolamine were introduced into the reactor at about 50 ° C.

To this mixture was added U6U, Tg of diluent 1. The resulting mixture was cooled to 25 ° C with stirring. A small amount of solid was formed at this stage. Circulation of the mixture through the wash column was started with continuous stirring. Sulfur trioxide vapor, mixed with nitrogen, obtained by passing nitrogen through liquid sulfur trioxide at a rate of 80-148 cm nitrogen / minute was introduced into the reactor through the gas feed tube at such a rate that in the course of about 7904648. β 3 h 1, IT mole of sulfur trioxide was added while the stirred mixture was kept at 25 ° C. After adding the entire amount of sulfur trioxide into the reactor, the reaction mixture was stirred for an additional 30 minutes and then the reaction mixture was heated to 5 116 ° C and kept at that temperature for 3 hours with stirring. The completion of the reaction was evident from the fact that the sodium 2-—, Ν-dimethylaminoethoxide content was reduced to a consistently low value.

The reaction product was distilled off into a short column until the distillation stirrer had reached 130 ° C, whereby N, ΪΓ-dimethyΙ-ΙΟ ethanolamine and the BDMEE formed were obtained as a product in addition to a small amount of diluent 1. Fractionation of this distillate through a column , with 35 ”dishes, delivered BDMEE as a fraction boiling at 88 ° C at 25 µm mercury pressure. The yield of BDMEE was between 63 and 68%, based on the sulfur trioxide used.

Example II

Synthesis of BDMEE with diluent 1

In the same establishment; as in example 1, bh 5.5 g (5.0 mol) Ν, Ν-dimethylethanolamine and hj2.5 g of diluent 1 were added to the mixture. reactor. The mixture was stirred and circulated through the wash column. A vaporous mixture, of sulfur trioxide and nitrogen, obtained by passing nitrogen gas through liquid sulfur trioxide * 3 at a rate of about 100 cm / min was passed through the gas inlet tube into the reactor over about 3 hours until 1.71 moles of sulfur trioxide in the reactor was charged while the stirred mixture was kept at 25 ° C in the reactor. After all sulfur trioxide was charged to the reactor, a hot solution (65 ° C) of 3.6 moles sodium 2-N, N-dimethylaminoethoxide in 5.5b moles N, N-dimethylethanolamine was added to the stirred mixture in the reactor . The resulting mixture was heated in the reactor at 110 ° C and held at that temperature for 3 hours with stirring. The reaction product was then distilled at 7 mm pressure through a short column, where the BDMEE and excess de, Ν-dimethylethanolamine were distilled off. The distillate contained 1.05 mole BDMEE, which corresponds to a yield of 61b% based on the sulfur trioxide used.

7904648 - 10 -

Example III

Synthesis of bis- [2- (N, N- <ethylethylamino) ethyl] ether with diluent. 2.

In the same facility as in. Example I A solution of 2.03 moles of sodium 2-N, N-diethylaminoethoxide in b-, 57 nol of N, N-diethyl ethanolamine was charged to the reactor at about 50 ° C. 51 µg of diluent 2 was added to this mixture. The resulting mixture was cooled to 25 ° C with stirring and then circulated through the wash column. A vaporous mixture of sulfur trioxide and nitrogen obtained by passing nitrogen through liquid sulfur trioxide at a rate of about 1 bcm / minute was passed through. into the gas supply pipe. The reactor was run over about 2 hours and 10 minutes, until 1.01 mole of sulfur trioxide had been introduced into the reactor while the stirred mixture was in the meantime. the reactor was kept at about 21 ° C. After; all sulfur trioxide had been charged to the reactor, the mixture was stirred for 1 hour, then refluxed at 110 ° C. The mixture was boiled under stirring for 11 hours and then it was cooled and filtered through a kieselguhr filter.

It. filtrate was then distilled through a 35-tray column to give 0.39 mole of bis- [2- (N, N-diethyalmino) ethyl] ether as a fraction boiling at 120 ° C at 15 mm mercury pressure. The yield of this substance was 39% based on the sulfur trioxide used. Example IV

Synthesis of bis [3- (Ν, Ν-dimethylamino) propyl] ether using diluent 3.

In the same apparatus as in Example I, a solution of 2.35 moles of sodium 3-N, N-dimethylamino-1-propoxide in U, 15 moles of 3-N, N-dimethylamino-1-propanol at 50 ° C in the reactor brought.

To this mixture was added 300 g of diluent 3. The resulting mixture was cooled to 25 ° C with stirring and then circulated through the wash column. A vaporous mixture of SO 2 and nitrogen 3 ^ was fed through the gas inlet pipe of the reactor at a rate of about 11 + 8 cm / minute until 1.07 mol of SO 2 was introduced after about 2 hours and 10 minutes. At that time, the temperature of the reaction mixture was kept at 25 ° C. After all SO4 had been added, the mixture was stirred for an additional hour and then refluxed at 125 ° C.

7904648 - 11 «- * ·

This heating was continued with stirring for 12 hours and then the mixture was cooled and filtered through a kieselguhr-covered filter. The filtrate was distilled through a 35-tray column to remove low boiling material and the remaining mixture was distilled through a column with 10 trays, whereby 0.36 mol bis [3- (N ,, N-dimethylamino) propyl] ether was obtained, boiling point 86-88 ° C at 5 mm mercury pressure. 34 #.

Example V

Synthesis of bis- [-2- (N, H-dimethylamino) -1-methyl-ethyl] ether using diluent 1.

In. the same apparatus as in Example 1, a solution of 2.48 moles of sodium -1-F, H-dimethylamino-2-pr opoxide in 4.92 moles of 1-N, H-dimethylamino-2-propanol was charged to the reactor. 15 graze on this mixture. 553 g of diluent 1 added. The resulting mixture was cooled to 18 ° C with stirring and then circulated through the wash column. A vaporous mixture of sulfur trioxide. and nitrogen obtained by passing nitrogen gas through liquid sulfur trioxide 3 with. a rate of about 148 cm / minute was introduced into the gas supply tube for about 2 hours until 1.17 moles of sulfur trioxide had been introduced into the reactor, meanwhile keeping the stirred mixture in the reactor at about 20 ° C . After all the sulfur trioxide was charged to the reactor, the mixture was stirred for 30 minutes and then heated to 115 ° C and held there for 2 hours and 45 minutes.

The mixture was then distilled through a short column at a pressure of 5 mm of mercury to give a distillate containing bis- [2- (N, N-dimethylamino) -N-methyl-ethyl] ether, the excess 1 -N, H-dimethylamino-2-pr opaole and a small amount of diluent 1. Redistillation of this distillate through a column with 35 trays yielded 0.57 mole of bis- [2- (Ν, ΙΓ-dimethylamino) -N-methylethyl] ether as a fraction boiling at 116-117 ° C at 50 mm Hg.

The yield of the latter was 49 #. based on the sulfur trioxide used.

7904648

Claims (17)

A process for preparing bis- (N, E-dialkylamino) alkyl ether of the formula (R ^ NR ') ^ 0, wherein R represents a methyl or ethyl group and R' represents a divalent alkylene group containing 2-3 carbon atoms, with characterized in that 5 a) a sodium N, N-dialkylaminoalkoxide with the. formula R ^ ERONa, wherein R and R 'have the above meaning. react with 0.1-0.8 mole SOg vapor / mole sodium E, N-dia, lkylaminoalkoxide at up to 90 ° C in the presence of I. a Ν, dial-dialkylaminoalkanol. with the formula R 1 ITR 'OH at a 10 mol ratio of sodium W, E-dialkylaminoalkoxide to N, E-dialkyl-aminoalkanol. between 1: .0.5 and 1: 3 and possibly. II. an organic diluent, b) heating the reaction mixture obtained in step A sufficiently low to form the desired bis (N, CT-diakylamino) alkyl ethers and c) recovering this product. 2. Process according to claim 1, characterized in that in step A 0.25-0.6 mol of SO2 vapor is used per mol of sodium N, dial-dialkyl-aminoalkoxide and step A is carried out at 20-90 ° C at a molar ratio of the sodium viir-Tir, di-dialkylaminoalkovyde-W, Ν-dialkylaminoalkanol 20 between about 1: 1 and 1: 3 and. in the presence of 0-60% by weight of organic diluent, based on the amount of sodium N, W-dialkyl aminoalkoxide and ϋΤ, dial-dialkylaminoalkanol. 3. Process according to claim 1, characterized in that 0.5-0.5 mole of SO2 vapor is used per mole of sodium N, N-dialkylaminoalkoxide. Process according to claims 1-3, characterized in that step A is carried out at 20-50 ° C. Process according to claim 1, characterized in that 10-50% by weight of organic diluent is used, based on the amount of sodium W, 1-di-dialkylaminoalkoxyda and N, N-dialkylaminoalkanol. 6. Process according to claims 1-5, characterized in that the molar ratio of sodium-N, W-dialkylaminoalkoxide: L1, W-dialkylaminoalkanol is between 1: 1 and 1: 2. 7. Process according to claims 1-6, characterized in that bis- [3- (1, N-dimethylamino) ethyl] ether is prepared starting from sodium 2- 790464813. W, f-dimethylaminoethoxide and I, W-dimethylethanolamine and while the diluent is a mixture of aliphatic hydrocarbons with 6-30 carbon atoms. 8. Process according to claims 1-6, characterized in that 5 his- [g- (ff, ff-diethylamino) ethyl] ether is prepared, starting from sodium-2 W, W-diethylaminoethoxide, ΪΓ, N-diethylethanolamine and use as a diluent a mixture of aliphatic hydrocarbons with 6-30 carbon atoms. 9. Process according to claim 1, characterized in that bis- [3-10 (W, W-dimethylamino) propyl] ether is prepared, starting from sodium-3-W, W-dimethylamino-1-propoxide and 3-ΪΓ ΙΓ-dimethylamino-1-propanol, while% diluent uses normal octane. 10. Process according to claims 1-6, characterized in that bis- [g- (W, W-dimethylamino) -1-methyl-ethyl] ether is prepared starting from sodium-1-W, W-dimethylamina-2-proporyde and 1-β-dimethylamino-2-propanol, the diluent being a mixture of aliphatic hydrocarbons having 6-30 carbon atoms. 11. Process according to claim 1, characterized in that a) a sodium 2-W, W-dimethylaminoethozyde is reacted with 0.4-0.55 mole SO 2 vapor / mole sodium W, W-dimethylaminoethoxide. at 20-50 ° C and in the presence of I ,. ΪΓ, ΪΓ-dimethylethanolamine in an amount sufficient to provide a molar ratio of sodium 2-,, J-dimethylaminoethoxide 11T, 11-dimethylethanolamine between about 1: 0.5 and about 1: 3; 25 II. An organic diluent in an amount of 10-50 percent by volume, calculated on the amounts of sodium 2-ϊί, iT-dimethylaminoethoxide and N, W-dimethylethanolamine for sufficient time to obtain the desired conversion, b) the reaction mixture obtained in step A is heated for sufficient time to form bis [2- (ff, W-dimethylamino) ethyl] ether and c) recover this product. 12. Process for forming bis-W, W-dialkylamino) alkyl ether of the formula JgOj in which R represents a methyl or ethyl group and R 'represents a divalent alkylene group of 2-3 carbon atoms, characterized in that a) potassium W, f-dialkylaminoalkozyde of the formula R ^ JIROK, 7904648 1U wherein R and R 'have the "meaning as defined above, react with 0.1-0.8 mole SO2 vapor / mole potassium-N, N-dialkylaminoalkoxide "at not more than 90 ° C and in the presence of I. a Ν, Ν-dialkylaminoalkanol of the formula R 1 NROOL, wherein 5 R and E 'have the above meaning in such an amount that the molar ratio of potassium-N β-dialkylaminoalkoxide: N, β-dialkyl-aminoalkanol is between about 1: 0.5 and 1: 3 and optionally an organic diluent, b) heating the product obtained in step A at an elevated temperature for sufficient time. time to form bis- (H, U-dialkylamino) alkyl ether and c) this product wins. 7904648 United Patent Offices a.o., no. 79-0k6kQ, 'mravenhage (Holland) „beh. "by letter dated June 30, 1990. u ^ -" '..I Verl / 654; ^ j ~ - -j JUL1980 | Improvement (s) ran erratum (a) in the description pertaining to patent application no. 79 * 01 + 61 + 8 proposed by applicant (star) under date 30 June 1980. -Inclause replacing p. 2, lines 3 ^ + - 36 first react a compound of the formula R ^ NR'OH with SO ^ vapor and with a sodium or potassium base to form an intermediate of formula R ^ EROSO ^ X, wherein X is sodium - or is a potassium atom, and then heats the compound R ^ RROSO ^ X obtained in the presence of a compound of formula R ^ ER'OX to form a compound of formula (R ^ ER ') ^ 0. A preferred embodiment of the invention is characterized in that a) a sodium hydroxide of the formula RgER'OEa is reacted with 0.1-0.8 and preferably with 0.1 + 0-0.55 moles of SO2 vapor per mole of sodium alkoxide at 10 a temperature below 90 ° C and preferably at .... * 790 4648 ~ COMPATIBLE PATENT OFFICES incl.no. 79-0½½. - «ravenmace (hollano) ^ beh. when writing dd. June 30, 1980. veri / 654. / J Improvement (s) of erratun (a) in the specification associated with patent application No. J9.0k6kQ. proposed by applicant {star) under date June 30, 1980. -000- Insert to replace page T. In step 2 of the reaction, the reaction mixture is heated, preferably at 100-120 ° C for sufficient time to obtain the desired bis- (Ν, Ν-dialkylamino) to form alkyl ether. The time required for step 2 is usually 1.5-12 hours and preferably 1.5-5 hours. The process according to the invention is usually carried out under atmospheric pressure, although an increased or reduced pressure can also be used if desired. Recovery of the bis (N, D-dialkylamino) alkyl ether can be carried out by any known method. Preferably, a distillation is used at the end of the 10 reactions. In that case, all operations including recovery of the product can be carried out directly in the reactor. As indicated in example II, the method according to the invention can be carried out in several ways. In a broad sense, the desired product of the formula (BgNE'JgO, wherein R is a methyl or ethyl group and R 'is a divalent alkylene group with 2-3 carbon, preferably bis- (II, W-dimethyl aminoethyl) ether , is prepared by first reacting a compound of the formula R 1 UR'OH, preferably 20 2- (dimethylamino) ethanol, with SO 2 vapor and with a sodium or potassium base, preferably with sodium 2- ( dimethylamino) ethoxide, to form a compound of formula RgNR'OSO ^ X »wherein X is a sodium or potassium atom, preferably the compound sodium dimethylaminoethyl sulfate, and then heating this compound in the presence of a compound of the formula R 1 IR'OX, preferably sodium 2- (dimethylamino) ethoxide, to form a compound of formula (RgNR'JgO, preferably bis- (2-dimethylarainoethyl) ether. 7904648 w7- -Ta. 30 add vapor to 2- (dimethylamino) ethanol and then sodium or potassium 2- (dimethylamino) ethoxide t add to the 2-dimethylaminoethanol sulfate formed in the first stage and thereby form the sodium or potassium dimethylaminoethyl sulfate in the second stage, as described in Example II. The sodium or potassium base need not necessarily be pre-prepared sodium or potassium 2- (dimetbylamino) ethoxy. For example, it is also possible to add liaCE or KOH as a solid or as a solution to the solution of the acidic 2-dimethylaminoethanol sulfate in 2- (dimethyl-amino) ethanol. In principle, any sodium or potassium base can be used, for example, sodium or potassium hydride or sodium metal, which then react with the 2- (dimethylamino) ethanol sulfate to form the sodium or potassium salt. In Example II, the sodium or potassium 2- (dimethylamino) ethyl sulfate reacts with the remaining sodium 2- (dimethylamino) ethoxy (which had not been converted to the sulfate) to form the desired product. When a base, such as sodium hydroxide, is used to form the sodium 2- (dimethylamino) ethyl sulfate, this 10H can also react with the 2- (dimethylamino) ethanol still present to form the corresponding sodium ethoxide, which is required to react with the 2- (dimethylamino) t-ethyl sulfate to form the bis-2- (dimethylaminoethyl) -ether. As said, the process of the invention can be used in the preparation of bis (ff, ff-dialkylamo) alkyl ethers of the type described above. Examples of such ethers are: bis- [3 (IT, N-dimethylamino) ethyl] ethers, bis- [3- (N, F-dimethylaari.no) -1 -15 methyl ethyl] ethers, bis- [3- (ff , N-dimethylamino) propyl] ethers, bis- [3-IT, N-dimethylamino) propyl] ethers, bis- [3- (ff, N-diethylamino) -ethyl] ethers, bis- [S- (1T, li -diethylainino) -1-methylethyl] ether bis- [3- (H, diethyl-amino) propyl] ether. Preferably, BDMEE is prepared. Other bis-ethers which contain tertiary amines and which do not fall under the above formula and which can still be prepared according to the method of the invention are the compounds of formulas 1 and 2 of the formula sheet. Such ethers are also useful as a catalyst in the preparation of polyurethane foam. The invention is illustrated by the following examples. 25 In the examples below, the following abbreviations are used: 790 4 848 "* * UNIFIED PATENT OFFICES o.a...no. 79-0U61 + 8, 's-axAVENHAGE (hólland) beh." At dd. June 30, 1980. • Ver 1/6 5 it 1 - ~ - - / 8 I ~ 1 JULV) 80 Improvement (s) ran erratun (a) in the description pertaining to patent application no. 79 · u6U8 proposed by applicant (star ) under date 30 June 19 ^ 0. -ooo- New conclusions 13 and I. 13. Process for extending a compound of general formula (RgNR's where R represents a methyl or ethyl group and R 'represents a divalent alkylene group of 2 or 3 carbon atoms, first reacting a compound of the formula RglR'OH with SO vapor 5 and with a sodium or a potassium base to form a compound of the formula RgNR'OSO ^ X, wherein X represents an atom of sodium or potassium and then heating the compound of the formula RgNR'OSO ^ X in the presence of a compound of the formula RgWR'OX to form the compound (R2NRf) 20. 10 IU Process for preparing bis- (1,1-dimethylaminoethyl) ether reacting first with dimethylaminoethanol with SO2 vapor and with a sodium base to form sodium dimethylaminoethyl sulfate and then heat this product in the presence of sodium dimethyl amino ethoxide to form bis- (N, dimethyl-aminoethyl) ether 790 4 6 48