METHOD FOR PRODUCING BIS(BETA-(N,N-DIMETHYLAMINO)ALKYL)ETHER

Abstract: A method for preparing a [β-(N,N-dimethylamino)alkyl]­ ether by reacting a bismethohalide of bis[β-(N,N-­ dimethylamino)alkyl]ether represented by the following gen­ eral formula (wherein R and R′ denote alkyl groups having 2 - 3 carbon atoms, and X denotes halogen atom,) with the aliphatic amine having 40 - 170°C of boiling point at atmospheric pressure and having one or two primary amino groups in a molecule thereof at an increased pressure.

Description: Method for producing frisLB- (N,N-dimethylamino) alkyl7ether DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a bisjB-(N,N-dimethylamino)alkyl?ether of the general formula given below: EMI1.1 wherein R and R' represent alkyl groups having 2 - 3 carbon atoms. The bisLB-N,N-dimethylamino)alkyl7ether is known to be an industrially very useful compound as a catalyst for producing a polyurethane foam which accelerates reactions between an alcohol group and an isocyanate group and between a water and the isocyanate group. There have been generally known the method of producing a tertiary amine compound by means of acting various nucleophilic reagents on the quarternary ammonium salt compound to effect a dealkylation reaction (14 III 1398 of New Experimental Chemistry Lecture, 1978) and also widely known the method of employing various amines having the active hydrogen as the dealkylation agent (395 - 407, 90 of Chem. Berichte - 1957). Similarly, the method for producing the corresponding bis(p -(N,N-dimethylamino )albyll ether (hereinafter referred to etheramine) afforded by a demethylation reaction of a bismethohalide (hereinafter referred to bismethohalide substance) of the bis[43 -(N,N-dimethylamino )alkyll eth-r? has been disclosed in U.S. Pat. No. 3,400,157 and Japanese Patent Publication No. Sho 48-7411 (U.S. Pat. No. 3,426,072). In the U.S. Pat. 3,400,157, the dealkylation reaction of said bismethohalide is undergone in aqueous solution of the dimethylamine to obtain the corresponding ether amine at 67% of yield which is not a sufficiently high yield. In particular, in this process, it is necessary to separate and recover the unreacted dimethylamine (7.40C of boiling point) which have been excessively added to the reaction system, and the trimethylamine (2.90C of boiling point) of the reaction by-product respectively after the reaction is completed. The both amines has the very low boiling point and further the difference of these boiling points is small, and therefore the handling and the separating operation thereof are complicated. Furthermore, the handling of the methylamines having the ammonia-like smell on a large scale may cause the environmental pollution problem. The Japanese Patent Publication No. Sho 48-7411 (U.S. Pat No. 3,426,072) features in the manufacturing process of the etheramine the process of affording the demethylation reaction to said bismethohalide in the polyamines having high boiling point of not less than 2200C and having a secondary or tertiary amino group together with a primary amino group of aminoethylethanolamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, dipropylenetriamine and the like, under reduced pressure. In order to make these polyamines of the demethylation agent having the high boiling point applicable to an economically industrial process, the repetitive applications of the polyamines are required. However, the primary and secondary amino groups of the polyamines having the high boiling point are methylated due to said reaction, to decrease the amount of the active hydrogen of the amino groups and lower the capacity of the demethylation agent1 and result in restricting the number of the re-application of the polyamines having the high boiling point greatly from aspect of the reaction. The aminoethylethanolamine is poor in the amount of the active hydrogen per unit weight based on the amino groups. The ethyleneamines of the high boiling point such as the triethylene tetramine and the like contain a lot of secondary and tertiary amino groups and are relatively low in the content ratio of the primary amine group which has the maximum active hydrogen, an account of being a mixture of the compounds including the piperazine rings, and so they are also poor in the amount of the active hydrogen per unit weight. Accordingly, they can be said to be disadvantageous dealkylation agents from the economical aspect. Furthermore, they have troublesome problems of the decomposition of the polyamines themselves, accompanies with drop of the recovery yield of the polyamines after the reaction and drop of the content ratio of the amino groups in the polyamines. The reaction yield of said etheramine is also 70 - 71% which are not so improved in comparison with the case of the dimethylamine In the process of producing the etheramine said bismethohalide of the raw-material and the amines of the demethylation agent are relatively expensive, and therefore it is desired to be able to produce said etheramine at higher yield. Still more, the amines of the demethylation agent suffers the structual changes such as -methylation and the like from the reaction concerned, to be limited in the repetitive applications thereof. Thus, the demethylation agents, which have excellent capacity in the production amount of said etheramine per unit weight of the amine and are economically advantageous, have been expected. In the light of the above circumstances, the inventors of this invention have made researches in the problem with their earnest efforts and found that the etheramine had been able to be produced at a marvelous high yield by reacting the bismethohalide with the aliphatic monoamine or diamine compound having the primary amino group only as an amino group as the demethylation agent under increased pressure, so they have completed this invention. Namely, this invention proposes a method for producing a bis[p N,N-dimethylamino)alkylgether by reacting a bismethohalide of a bis^(N,N-dimethylamino)alkysether represented by the general formula: EMI5.1 ,(wherein R and R' represent alkyl group containing 2 - 3 carbon atoms and X represents halogen atom,)with an aliphatic amine having 40 - 1700C of boiling point under atmospheric pressure and having 1 - 2 primary amino groups in the molecule thereof, under increased pressure. The bismethohalide of the raw material used in this invention is represented by the following general formula: EMI5.2 Namely, the bismethohalide of the bis[ss-(N,N-dimethyl- amino)alkylether wherein, in general, R and R' represent alkyl groups containing 2 - 3 carbon atoms and X represents halogen atom can be widely used as the raw material therefor. Among the bismethohalide, from economical stand points and procurement circumstances of the raw material1 as the preferable raw materials used in this invention are exemplified bismethochloride of bis (N,N-dimethylamino)ethyl ether, bismethochloride of 1-methyl-2(N,N-dimethylamino)ethyl-2' (N, N-dimethylamino) ethyl) ether and bismethochloride of bis l-methyl-2(N,N-dimethylamino)ethylzether. The aliphatic amine used in this invention is the compound having a boiling point in range of 40 - 1700C under atmospheric pressure and having 1 - 2 primary amino groups in the molecule thereof. In other words, the aliphatic amine is featured in not containing the secondary or tertiary amino group but having the primary amino group only in the molecule thereof. The geneRal chemical formula of the aliphatic amines is represented as follows. NH2-R wherein R represents alkyl group containing not less than 4 carbon atoms. NH2-R" -NH2 wherein R" represents alkylene group containing not less than 2 carbon atoms. =7Erg As the ty-pioulFcompounds thereof, butylamine, ethylene- diamine, propanediamine, butanediamine and the like are exemplified. Among these amine compounds1 ethylenediamine, 1, 2-propanediamine, 1, 3-propanediamine and 1,4-butanediamine are preferably used from the aspects of reactive activity1 yield and economy. In particular, the ethylenediamine and the propane diamine are excellent in the production capacity of the etheramine per unit weight of amine and very advantageous economically. The aliphatic primary amine compounds of not more than 40 C boiling point may be used for the reaction but the use of these amines of the low boiling point requires the complicated recovery operations as in the case of dimethylamine and further requires the operation under a relatively high reaction pressure, so the use thereof is not preferable from the aspect of the apparatus. On the other hand, the aliphatic primary amine compounds of not less than 1700C of boiling point may be also used for the reaction but are not preferable from the operative and economical aspects since there arise troublesome problems in separating these amines of high boiling poiht from said etheramine by distillation and the production capacity of the etheramine per unit weight of amine is low. The method of the reaction in this invention essentially comprises the processes that the bismethohalide of the raw material and the aliphatic primary amine based on this invention are firstly charged into the reactor and then are subjected to a reaction at an elevated temperature to produce the etheramine of the object. The addition amount of the aliphatic primary amine is usually more than 2 mols to 1 mol of said bismethohalide. For example, in case of performing the reaction in a non-aqueous system, the aliphatic primary amine should be added by at least 2 mols, preferably not less than 3 mols1 in order to disperse said bismethohalide. The addition of less than 2 mols aliphatic primary amines do not improve the dispensibility and the drop of the yield appears. The upper limit for the addition amount of the aliphatic primary amine is not particularly specified but selected for an efficient amount in consideration of the production efficiency of the reactor and the recovery amount of amines after the reaction thereof1 etc. The reaction is usually undergone without solvent and diluent but may be undergone under the existence of water and various organic diluents. In case the aqueous solution of the bismethohalide is used as the raw material, the reaction has an advantageous on the operation aspect since the reaction becomes a liquid phase reaction by using water as the solvent but the use of water is not advantageous since phenomenon such as accelerating of corrosion in the reactor becomes remarkable under the co-existence of water. These diluents are effective to advance the dispersibility of the bismethohalide but the addition amount of those diluents are usually less than the equal weight parts to said bismethohalide. The reaction of this invention is usually performed under the temperature of 140 - 1900C. The temperature of not less than 1900C makes the control of the reaction temperature resulted by a quick reaction difficult and brings about drop of yield due to the decomposition of the product. Further, the temperature of not more than 1400C is not practicable because of a slow reaction rate. The reaction between the bismethohalide and the aliphatic amine requires the sufficient contact between them over the period up to completion of the reaction and it is indispensable to perform it under increased pressure to prevent the aliphatic amine from distilling out towards the outside of the reaction system during the reaction. The reaction pressure varies, depending on the kind and amount of the aliphatic amine and the diluent, and on the reaction temperature, but this reaction can be usually performed under a relatively low pressure of lower than 10 kg/cm2. For the industrial production of said etheramine,the aliphatic amine is required to be used repeatedly for the reaction to advance economical value of the process. Namely, after the reaction, the reaction mixture comprising hydrochloride salts of amines are added with alkaline compound to liberate and recover the amines. The alkaline compounds used for the neutralization are not specified but exemplify hydroxide, carbonate, etc. of the alkali metal. The sodium hydroxide or potassium hydroxide is usually used as an aqueous solution and the addition amount thereof is not less than twice mol equivalents of the bismethohalide of the raw material, e.g. approximately 2.0 -2.2 times mol equivalents. After the neutralization, the aliphatic amine and said etheramine are recovered from the mixture consisted of the amines, water and salt through the conventional separating means of distillation, filtration, extraction, etc. The recovered aliphatic amines are reused for the subsequent reactions repeatedly. The repetitive applications of the aliphatit amines as the demethylation agent increase the production amount of said etheramine per unit weight of amine, thereby remarkably elevating economical value of the process. As in the foregoing description, the application of the aliphatic amine as the demethylation agent can obtain the etheramine yield of exceeding the conventional reaction yield greatly and still maintains a very high yield of said etheramine and hardly result drop of the demethylation capacity even if it is used three times repeatedly. The aliphatic amine of this invention differs from the polyamines of high boiling point containing many secondary or tertiary amine groups and is not so much recognized of the phenomenon for the decomposition of the amine itself e.g. drop of reaction activity due to the elimination of the amino group, etc. Therefore, the aliphatic primary amine proposed by this invention is recognized as a very advantageous demethylation agent in the industrial process which is suitable for the repetitive reactions. This invention proposes one improved-method of the aforesaid basic invention relating to producing bisR -(N,N- dimethylamino)alkyljether. In the basic invention, the method for recovering the beforementioned aliphatic amine comprises multistage separation such as distillation-centritugal separation-distillation of the reaction mixture after neutralized, and therefore it constitutes a complicated separating and recovering method. Additionally, there is another complication of handling a solid-containing slurry, and therefore it can not be necessarily said to be a favorable process from the aspect of operating property. In case the employed aliphatic amine forms no azeotrapic mixture with water1 it is possible to recover said aliphatic amine by removing water selectively from the reaction mixture after neutralized through distillation, followed by further desalting and distillation. However, in case of using the aliphatic amine which forms an azeotrapic mixture with water such as ethylene diamine as the demeChylation agent, water can not be selectively removed through conventional distillatiqn under. ordinary pressure. In other words, as to some kinds of the aliphatic amines, it is difficuLt to separate and recover the aliphatic amine from water and salt through the abovestated process comprising a series of operations such as dehydration by distillationdesalting by centrifugal separation-distillation. In the production process of etheramine in which the raw material bismethohalide is reacted with the aliphatic amine having 40 - 17006 boiling point and having primary amine and further the aliphatic amine recovered from the reaction mixture is used repeatedly, there has been strongly desired a very simple way of separating and recovering the aliphatic amine which can be applied universally without depending on the kind of the aliphatic amine and in even case of employing said aliphatic amine of any chemical structure as the demethylation agent. In particular, there has been strongly desired the establishment of the industrial production process of etheramine in which the separating and recovering process is simple and excellent in the operating property and no special separating apparatus is required1 thereby being advantageous in the aspect of facilities and being economically excellent. The inventors, upon reviewing these circumstances, has elaborately studied to find out a new fact that a reaction of the bismethohalide with the aliphatic amine having primary or secondary amino group yields the reaction mixture which is separated into two of an upper layer and a lower layer, etheramine of the objected product can be recovered from the upper layer and the aliphatic amine of the demethylation can be recovered from the lower layer. Furthermore, they had found that the recovered aliphatic amine can be'reued as such for the reaction with the bismethohalide, if it is treated with addition of alkali metal hydroxide when the aliphatic amine is recovered from the lower layer, and have completed this improved invention, based on this finding. That is, this invention also propose a method for producing a bis{(N,Ndimethylamino)ethyi) ether wherein a bismethohalide of bis0 -(N,N-dimethylamino)ethyljether represented by a general formula EMI12.1 (X denotes halogen atom) is reacted with the aliphatic amine1 which comprises (a) separating and recovering respectively an upper layer liquid and a lower layer liquid from a reaction mixture having two separated upper and lower layers obtained by the reaction of said bismethohalide with the aliphatic amine having primary or secondary amino group (b) adding alkali metal hydroxide to the lower layer liquid so as to be in a concentration of 10 - 55 weight% to water amount of the lower layer liquid and thereafter recovering the aliphatic amine (c) further reusing the recovered aliphatic amines for the reaction with said bismethohalide compound. In case of this improved method, the aliphatic amine which can be used in this invention is not particularly restricted, so long as it contains primary or secondary amino group it the molecule thereof. However, among these the aliphatic amines having the active hydrogen which comes from the amino group, a compound having the boiling point in range of 40 - 1700C under atmospheric pressure and having 1 - 2 primary amino groups in the molecule thereof is the very useful aliphatic amine from the aspects of the reaction yield and the economics,xfo; it can produce etheramine at high yield. Exemplifying the typical compounds thereof, n-propylamine, butylamine, ethylenediamine, propanediamine, butanediamine and the like are preferable used. Particularly, ethylenediamine and propanediamine are used as very useful aliphatic amines, for they are excellent in the production capacity of etheramine per unit weight of the amine, moreover these are easily available and so on. The production process of etheramine in this invention essentially comprises a step of reacting the raw material bismethohalide with the aliphatic amine of demethylation agent and a step of separating and recovering the aliphatic amine from the reaction mixture in order to reuse it as the demethylation agent. The mode of reaction in the above steps is not particularly restricted, but it is usually performed in the following way. That is, the reaction of the bismethohalide with the aliphatic amine is practiced under ordinary pressure or increased pressure at a temperature of 100 - 19000. In case the aliphatic amine of relatively low boiling point is employed, the reaction is carried out under increased pressure at an elevated temperature, in order to prevent the aliphatic amine from escaping outside the reaction system. Also, in case an aliphatic amino having a relatively high boiling point is emFtóyed, the reaction may be carried out under ordinary pressure with refluxing and cooling. The addition amount of the aliphatic amine is usually not less than 2 mols to 1 mol of the bismethohalide. The upper limit of the addition amount of the aliphatic amine is not particularly restricted, but an effective amount thereof is selected in consideration of the production efficiency of the reactor, the recovering charge and the like accompanied with the recovered amount of the aliphatic amine after used. The aliphatic amine not only acts as demethylation agent of the bismethohalide but also has a function of diluting and dispersing agent in order to improve the dispersing property of the bismethohalide. Therefore, it is not always necessary to add the diluting and dispersing agent into the reaction system additionally. As described in Japanese patent publication No. Sho 48-7411 (U.S. Pat No. 3,426,072), it is generally practiced in a system of using an aliphatic amine which is close to nonaqueous system as the diluting and dispersing agent or in a system in which a diluent of glycolethers is added. As water is used in the process of producing the raw material bismethohalide, the water accompanied with the raw material is introduced into the reaction system of the present process. As this result, the reaction can be performed in a system of adopting water as the diluent together with the aliphatic amine likewise as the reaction method of this invention. The use of the diluent such as water and the like is not particularly advantageous in the aspects of the etheramine yield and the efficiency of the reactor, so the addition amount thereof is favourably not more than equal weight parts to the bismethohalide. In order to produce etheramine on industrial scale, it is important to elevate the economical value of this process by recovering the aliphatic amine from the reaction mixture obtained by the aforesaid reaction, followed by reusing it repeatedly. In any reaction method of the reaction of the bismethohalide aqueous solution with the aliphatic amine and of the reaction of the solid bismethohalide with the aliphatic amine1 the reaction mixture after completion of the reaction come to be separated into two of the upper and lower layers. The separating and recovering method of this invention consists of separating and recovering the upper layer liquid and the lower layer liquid from the reaction mixture separated into two layers, followed by performing the following treatment. That is, the upper layer liquid consisting of mainly etheramine undergoes distillation as such to give the product of etheramine. At this time, the part of aliphatic amine dissolved into etheramine layer is also recovered, so the recovered one can be repeatedly reused as the demethylation agent. On the other hand, the almost part of aliphatic amine exists in the lower layer liquid in state of being free and in state of hydrogen halide acid salt. With addition of alkali metal hydroxide to this lower layer liquid, neutrals zation reaction occurs at first, and the free amine comes to be formed. After neutralization of hydrogen halide acid, alkali metal hydroxide is added thereto so that the concentration of alkali metal hydroxide may be 10 - 55 weight%, preferably 20 - 52 weight% to water content in the liquid. The liquid treated like this comes to separate into a slurry-like lower layer containing deposited solid of neutral salts etc. and a supernatant liquid of liberated amines. This liquid phase containing amines is separated and recovered from the slurry-like solid phase to obtain the recovered amine. Furthermore, said recovered aliphatic amines contain various amines produced by side reactions and small amount of inorganic compounds etc., but the recovered aliphatic amines can be reused as it is in the reaction with the bismethohalide. The alkali metal hydroxide used in this invention is not particularly restructed, but sodium hydroxide or potassium hydroxide is usually in state of solid or aqueous solution. In order to depress the water amount brought into the system to the utmost, it is recommendable to use solid alkali metal hydroxide. The concentration of alkali metal hydroxide added further after the neutralization is defined as follows. The concentration of alkali ¯¯¯¯¯¯¯¯¯¯¯¯ C x 100% metal hydroxide = + B + C A: weight of water in the lower layer liquid after the reaction of producing etheramine B: weight of water formed by the neutralization reaction C: weight of alkali metal'hydroxide existing in the system When the concentration of alkali metal hydroxide in the system is less than 10 weight%, neutral salts are still dissolved in the recovered aliphatic amine liquid, so desalting from the recovered aliphatic amine layer is not enough. Then, in case the liquid mixture of aliphatic amines recovered under these condition is used as it is repeatedly as the demethylation agent, yield of etheramine is lowered and therefore it is not favourable as the demethylation agent. Even if alkali metal hydroxide is added so as to be a concentration of more than 55 weight%, the recovered aliphatic amine is not endowed with more favourable property as the demethylation agent, and then it brings about only economical loss due to excess addition of alkali metal hydroxide. The operating conditions at the time of adding alkali metal hydroxide to the lower layer liquid and treating it with stirring are not particularly restricted, but the following conditions are preferably selected. That is, the treatment is operated at a temperature of more than 200C but lower than boiling point of the aliphatic amine, preferably at a temperature of 40 - 12O0C. Higher the treatment temperature is, sooner the treatment operation is completed, and effective treatment of the lower layer liquid becomes feasible. In case the treatment is performed in a temperature range of 40 - 1200C, the treatment is usually completed within 0.5 - 5 hours1 so the slurry-like solid containing neutral salts etc. come to be sedimented. When, after leaving it to stand, the supernatant liquid is separated and recovered from the slurry-like solid phase1 amines existing in the lower layer can be almost quantatively recovered. Also, the separation of solid phase and liquid phase may be practiced by centrifugal separation. Even if the liquid recovered by only thus phaseseparating operation is repeatedly used as the demethylation agent1 etheramine can be still produced at high yield. As beforementioned, the recovered aliphativ emEnas ; can be repeatedly used as the demethylation agent by a very simple separating operation comprising the combination of alkali metal hydroxide treatment of etheramine resulting reaction mixture with phase-separating operation. The production process of etheramine by this invention not only is improved remarkably in operations but also requires no special facilities. That is, the industrial production of etheramine becomes feasible by utility instruments,and therefore it can be said to be a very useful method from the aspect of facilities. Furthermore, even if the aliphatic amines recovered Dy the method based on this invention are used repeatedly for the reaction with the bismethohalide, etheramine can be constantly produced at high yield. In other words, the method of this invention can be said to be an industrial process for producing bi-(N,N dimethylamino)ethyl)ether which is extremely excellent by economical reasons also. This invention further proposes another improved method of the aforesaid basic invention. In the basic invention, the method for recovering the beforementioned aliphatic amine comprises multistage separation operations such as distillation of the reaction mixture after neutralizedcentrifugal separation-distillation, and therefore it constitutes a very complicated separating and recovering method. An important point in the process of recovering the aliphatic amine of the demethylation agent for recycled use thereof lies in that the salt generated by neutralization'1 water carried into the reaction system accompanied with the ras material bismethohalide and the recovered aliphatic amine, further water generated by the neutralization reaction and other substances which give unfavorable influences on the etheramine yield are removed out of the system with good efficiency through a-simple operation. Upon reviewing these circumstances, the inventors had made elaborate studies to find out the following new facts. (1) An extremely simplified treating method of the reaction mixture capable of performing neutralization, desalting and dehydration of the reaction mixture rapidly all at once by practicing an essentially simple operation consisting of adding alkali metal hydroxide to the reaction mixture of the bismetho halide substance with the aliphatic amine having active hydrogen based on amino group (2) Etheramine can be produced at high yield in even case the liquid treated by the above method is sub jected to crude distillation to separate and recover a distillate of boiling point of less than 1700C comprising mainly said aliphatic amines and various kind of organic matters, thereafter the recovered one is reused repeatedly as the demethylation agent. This improved invention has been completed, based on the findings of the above new facts (1) and (2). This invention further also proposes a method for producing a bis(ss-(N,N-dimethylamino)ethylgether wherein a bismethohalide compound of bis6-(N,N-dimethylamino)ethyl) ether represented by a general formula EMI21.1 (X denotes halogen atom) is reacted with an aliphatic amine having boiling point of 40 - 1700C under atmospheric pressure and having 1 - 2 primary amine group in the molecule thereof 1 which comprises (a) adding alkali metal hydroxide so as to be 10 - 55 weight% to water amount in the reaction system, after completion of the reaction of said bismethohalide with said aliphatic amine (b) separating and recovering a liquid phase consisted of the amines (c) separating the recovered amine into a distillate of boiling point of not exceeding 1700C under atmospheric pressure and a distillate of that of exceeding 1700C by distillation (d) reusing the recovered amine having boiling point of not exceeding 1700C under atmospheric pressure in the reaction with said bismethohalide. In case of this improved method, the aliphatic amine which can be used in this invention is one having boiling point of 40 1700C and having 1 - 2 primary amino groups in the molecule thereof. The separating and recovering method of this invention consists of performing the following treatments. That is, the reaction mixture of the raw material bismethohalide with the aliphatic amine is consisted of the resultant etheramine, the mixture of said aliphatic amines which has received methyl group from the bismethohalide to be partially denatured in the structure thereof, water which has been brought into the reaction system with the raw material, hydrogen halide acid and various side reaction products. With addition of alkali metal hydroxide to this reaction mixture, at first hydrogen halide acid is neutralized to produce liberated amines1 and then alkali metal hydroxide is added thereto so that the concentration of alkali metal hydroxide may be 10-55 weight%, preferably 20 - 52 weight% to water content in the liquid. The liquid treated like this comes to separate into a slurry-like solid phase and a liquid phase consisting of mainly various amines. From the solid and liquid phase obtained like this, the liquid phase consisting of amines is separated and recovered. Further, the recovered amines are separated into a distillate of boiling point of not exceeding 170 C (under atmospheric pressure) and etheramine of a distillate of one of exceeding 1700C. Etheramine is available as the product, and the recovered amines of boiling point of not exceeding 1700C which consist of mainly the mixture of said aliphatic amines can be reused as it is, without doing rectification, in the reaction with the bismethohalide. The alkali metal hydroxide of this invention is used likewise as in the foregoing improved invention, in respect to the kind, the mode of addition, the concentration thereof further added after the neutralization and so on. When the concentration of alkali metal hydroxide in the system undergoing further addition thereof after the neutralization is less than 10 weight%, dehydration from the reaction mixture is not enough. Hence, if the'disti11'4f6 boiling point of not exceeding 1700C, containing much amounts of water, is used repeatedly in the reaction with the bismethohalide, the increased water amounts in the reaction system cause drop of utilizing efficiency of the reactor and further fall of yield of etheramine. Furthermore, desalting is not enough, and therefore when the liquid treated with alkali metal hydroxide is subjected to crude distillation, the salts remain in the distillation pot to cause corrosion thereof. Even if alkali metal hydroxide is added so as to be a concentration of more than 55 weight%, it brings about only economical loss due to excess addition thereof. The operating conditions at the time of adding alkali metal hydroxide to the reaction mixture and treating it with stirring are the same as beforementioned. Through this operation, the desalted and dehydrated liquid consisting of mainly etheramine and the aliphatic amine mixture is recovered after separated from the solid phase. This separating and recovering method can be practiced by filtration with addition of auxiliary filtration agent, decantation of the supernatant liquid, centrifugal separation or the like. In case these recovered amines are subjected to distillation to obtain the product etheramine (boiling point 1900C/760 mmHg), the fore-running of boiling point of not exceeding 1700C which consists of mainly the mixture of said aliphatic amine is recovered and it is reused for the reaction with the bismethohalide. As the condition of distillation is not particularly restricted, it can be practiced under any pressure of ordinary pressure, reduced pressure or increased pressure, but it is usually practiced under ordinary pressure or reduced pressure. In case the treated liquid undergoes distillation, only a distillate having boiling points of said aliphatic amine mixture may be recovered by rectification to be reused in the reaction with the bismethohalide, but it does not become so beneficial in the aspect of apparatus and labour. Fundamentally, the etheramine producing process is satisfied by the simplified distillation operation comprising distillation to separate the treated liquid into a distillate of etheramine and a distillate consisting of the other composition and reusing the distillates other than etheramine for the reaction with the bismethohalide. As mentioned above, the process of producing etheramine by this invention, wherein the aliphatic amines mixture recovered by the extremely simplified separating operation consisting of a combination of alkali metal hydroxide treatment of etheramine resulting reaction mixture with crude distillation operation can be used repeatedly as the demethylation agent, not only improves operating property remarkably but also is considered to be also a very useful method from the aspect of facilities, for it makes an industrial production of etheramine feasible by utility instruments, without any special facilities. Furthermore, although a distillate comprising the aliphatic amines mixture recovered by the method based on this invention is used repeatedly for the reaction with the bismethohalide, etheramine can be produced at high yiel. Accordingly, this process of this invention is considered to be, from the economical aspect, a very excellent industrial methof of bis[ss-(N,N-dimethylamino)ethyl]ether. Hereinafter, this invention is explained in details by examples, but it does not undergo restrictions by these examples. EXAMPLE 1 Preparation of bismethochloride of bis[ss-(N,N-dimethyl- amino)ethyl)ether Into a stainless steel autoclave of inside volume 5 lit-er equipped with a magnetic stirrer, 2,820g of 30% tri methylamine aqueous solution (846g of 'trimethylamine) and 860g of bis(P-chloroethyl)ether were introduced and heated at 70 C to be subjected to a reaction for 6 hours. After the reaction, excess of unreacted trimethylamine was purged out, and the reaction mixture was analysed. As a result of quantitative analysis of chlorine ion by Volhard method, it was 12.0 equivalents (theoretical value 12.02 equivalent). By 'H-NMR and 13C-NMR,analysis of the reaction mixture, it was identified that the product was bismethochloride of bis[ss-(N,N-dimethylamino)ethyl]ether and it was produced nearly quantitatively. Preparation of bis[ss-(N,N-dimethylamino)ethyl]ether Into a stainless steel autoclave of inside volume 500 ml equipped with a magnetic stirrer, 149g of 70% bismethochloride of bis[ss-(N,N-dimethylamino)ethyl]ether aqueous solution (104.3g of bismethochloride) and 176gof n-buylami e were introduced and heated at 1700C for 3.5 hours to be subjected to a reaction. During the reaction, the pressure varied and the maximum pressure was about 6 kg/cm2. After the reaction1 the reaction mixture was added with 67g of 48% sodium hydroxide aqueous solution and then deposited sodium chloride is filtered by the centrifugal separation. Next, as a result of quantitative analysis of the filtrate by the gas chromatography, it turned out that 51.2g of bis(N1Ndimetylamino)ethyl} ether was obtained. Based on bismethochloride, the yield thereof was 79.5%. The product was isolated by distillation and was subjected to 'H-NMR analysis. It was identified to be bist -(N,N-dimethyl- amino)ethyl) ether. EXAMPLE 2 Into the same reactor as in example 1, 149g of 70% bismethochloride of bi4 -(N,N-dimethylamino) ethyl) ether aqueous solution produced in example 1 (104.3g of bismethochloride) and 168g of ethylenediamine were introduced and were subjected to a reaction at 1600C for 5 hours. As the reaction proceeded, the reaction pressure varied with lapse of time, and the maximum pressure was about 5 kg/cm2. After the reaction, the reaction mixture was added with 68g of 48% sodium hydroxide aqueous solution and the deposited salt was filtered by the centrifugal separation. As a result of chromatographic analysis of the filtrate, it turned out that 58.6g of bisk -(N,N-dimethylamino)ethyl)ether was produced. Based on bismethochloride substance, the yield was 91.0%. EXAMPLE 3 - 6 Into the same reactor as in example 1, 105g of bismethochloride of bisL -(N,N-dimethylamino)ethyl ether and the prescribed amount of the aliphatic primary amine shown in Table 1 were introduced to be subjected to a reaction at a reaction temperature of 155 - 1800C for 2 - 8 hours.. After the reaction, the reaction mixture was added with 70g of 48% sodium hydroxide aqueous solution and the deoposited salt was filtered by the centrifugal separation. The filtrate was analysed quantitatively by the gas chromatograph. These results were shown in Table 1. Table 1 No. of aliphatic primary reaction reaction yield of Example amine tempera- time etheramine ture( C)(hour) (.%) 3 butanediamine 167g 185 1.0 91.2 4 propanediamine 150g 175 2.5 93.4 5 ethylenediamine 90g 160 5.0 90.7 6 ethylenediamine 170g 170 3.5 94.0 EXAMPLE 7 Into the same reactor- as in example 1, bismethochloride of bis[ -(N,N-dimethylamino) ethyl) ether and 1, 3-propanediamine were introduced in the amounts shown in Table 2 respectively to be subjected to a reaction at a reaction temperature of 1700C and under a reaction pressure of 3.5 - 4.0 kg/cm2 for 3.5 hours. After completion of the reaction, 48% aqueous solution of sodium hydroxide was added in amount of twice of the raw material bismethochloride substance (as NaOH). Then, water was distilled out from the reaction mixture by the distillation. After the deposited salt was removed by the centrifugal separation, the filtrate was subjected to the distillation, so a mixture of denatured compounds of 1,3propanediamine and bislP -(N ,N-dimethylamino) ethyl ether were separated and recovered. The recovered mixture of denatured compounds of 1,3-propanediamine was used repeatedly in the second time reaction. The same reaction and recovering operation were carried out three times. The yield of etheramine was calculated from the amount recovered by the disti11ai.---The obtained results were shown in Table 2. Stable 2 No. of Bismethochloride 1,3-propane- yield of ether Repetition (g) diamine (g) amine (weight%) first time 105 237 56.3 (87.4) second time 100 232 *) 54.9 (88.7) third time 95 224 *) 50.7 (86.2) The demethylation agents of the second time and the third time were the mixture of denature compounds of 1,3-propanediamine (mainly N-methylated compounds) recovered after the first time reaction and the second time reaction respectively. COMPARATIVE EXAMPLE 1 Into the same reactor as in example 1, 70 weight% aqueous solution of bismethochloride of bislp -(N,N-dimethylamino) ethyl ether and aminoethylethanolamine (boiling point 243.70C) were introduced in the amounts shown in Table 3 and were subjected to a reaction at a reaction temperature of 1700C and under a reaction pressure of 2 - 3 kg/cm2 for 3.5 hours. After completion of the reaction, 48% aqueous solution of sodium hydroxide was added in amount of 2.1 times of the raw material bismethochloride (as NaOH). Then, water was distilled out from the reaction mixture by the distillation. After the deposited salt was removed by the centrifugal separation, the filtrate was distilled and bis6ss-(N,N-dimethyl- amino)ethylgether and the mixture of denatured compound of aminoethylethanolamine were separated and recovered. The recovered mixture of denatured compounds of aminethylethanolamine was used repeatedly in the second time reaction. The same reaction and recovering operation were carried out three times The yield of etheramine was calculated from the amount recovered by the distillation. The obtained results were shown in Table 3. Table 3 No. of bismethochloride aminoethyl- yield of etherrepetition (g) ethanolamine amine (g) ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯ (g) wt(g) (%) first time 105 237 43.9 (68.4) second time 97 227 *) 39.2 (66.1) third time 88 210 *) 34.1 (63.3) *) The methylation agents of the second time and the third time were the mixture of denatured compounds of aminoethylethanolamine recovered after the first time reaction and the second time reaction respec tively. EXAMPLE 8 Into a stainless steel autoclave of inside volume 5 liter equipped with a magnetic sitrrer, 1,258g of 70% aqueous solution of bismethochloride of bisLss ¯(N,N-dimethyl- amino)ethyl|ether, (880.6g of bismethochloride) and 1,800g of ethylenediamine were introduced and were subjected to a reaction at a reaction temperature of 1500C and at a pressure of 2.8 - 3.5 kg/cm2 for 6 hours. After completion of the reaction1 the reaction mixture was cooled to the room temperature and was transferred to a separating funnel of inside volume 5 liter. The reaction mixture separated uniformly into two layers of upper and lower ones was taken out respectively to recover 730g of the upper layer liquid and 2,317g of the lower layer liquid. As a result of chromatographic analysis of the upper layer liquid, it was recognized that 469g of etheramine was present. The recovered upper layer liquid was distilled to be separated into a low boiling temperature mixture having the boiling point of not exceeding 1400C and etheramine (boiling point being about 1900C). The lower layer liquid was transferred to a four neck flask made of gloss equipped with a stirrer and a refluxing cooler and was added with 620g of solid hydroxide. They were treated with stirring at a temperature of 80 - 900C for 4 hours. From the mixture treated with sodium hydroxide, 1,820g of a supernatant liquid was recovered. As a result of gas-chromatographic analysis of the supernatant liquid, it was asertained that 19.8g of etheramine and 1,630g of ethylene diamine and N-methylated ethylenediamines (the denatured compounds of ethylenediamine) were present. The total amount 2,070g of the low boiling point mixture of 250g recovered from the upper layer liquid and the supernatant liquid 1,820g recovered from the lower. layer liquid as mentioned above were used as the demethylation agent for the second time production of etheramine. With performance of the same recovering procedures, the repeated reactions were carried out four times in the same conditions Åas in the first time reaction. The yield of etheramine was calculated by substracting the amount of etheramine introduced into the reaction system with the denatured compounds mixture of ethylenediamine from the amount ofthe produced etheramine in the reaction mixture. Ethylenediamine recovered from the upper layer and lower layer was without any fresh ethylenediamine additional supply, used repeatedly. The result was shown in Table 4. Table 4 No. of 70% aqueous solid NaOH NaOH etheramine repeti- solution of addition concention bismetho- amount (g) tration yield chloride(g) (wt%) (wt%) (g) (%) 1st time 1258 620 42.8 488.8 90.0 2nd time 1258 820 46.3 489.3 90.1 3rd time 1258 820 46.5 487.0 89.7 4th time 1258 500 26.7 475.2 87.5 EXAMPLE 9 Into the same reactor as in example 8, 85% aqueous solution 921.7g of bismethochloride of bisgss -(N,N-dimethyl- amino)ethylgether (783.7g of bismethochloride) and 1,550g of 1,3-propanediamine were introduced and were subjected to a reaction at a reaction temperature 1700C and a reaction pressure 3.5 - 4.5 kg/cm2 for 4 hours. After completion of the reaction, the reaction mixture was cooled to the room temperature and was transferred to a separating funnel. The reaction mixture separated into two layers of upper and lower ones was taken out respectively to recover 660g of the upper layer liquid and 1,794g of the lower layer liquid. As a result of gas-chromatographic analysis of the upper layer liquid, the existence of etheramine 427g was recognized, the lower layer liquid was transferred to a four neck flask made of glass equipped with a stirrer and a refluxing cooler and was added with 3'5lug of solid sodium hydroxide. They were treated with stirring at a temperature of 60 - 800C fow.5 $ hours. After this treated liquid was left to stand, 1,460g of a supernatant liquid was recovered. As a result of gas chromatographic analysis of the supernatant liquid, it was recognized that 18g of etheramine and 1,370g of 1,3-propanediamine and N-methylated compounds mixture were present. In the second time reaction,o,f producing etheramine, 1,510g of the supernatant liquid containing 1,370g of the denatured compounds mixture of 1,3-propanediamine recovered from the lower layer liquid was, with an additional supply of 1,3 -propanediamine 200g, used as the demethylation agent. In the repeated reaction, the same separating and recovering procedures were also carried out at the second and the further following times, and the obtained treated liquid of the lower layer additionally supplemented with 200g of fresh 1,3-propanediamine was used as the demethylation agent in the next time reaction. The recovery and reusing of the denatured compounds mixture of 1,3-propanediamine from the upper layer after the reaction of producing etheramine were not carried out. The yield of etheramine was calculated in the same way as in example 8. The repeated reactions were carried out four times and these results were shown in Table 5. Table 5 No. of the raw mate- addition addition NaOH etheramine repeti- rial bisme- amount of amount of concention thochloride 1,3-propane- solid tration yield (g) (g) diamine (g) NaOH (g) (wt%) (g) (%) 1st time -921.7 1550 351 31.7 445 92 2nd time 921.7 200 350 40.5 438 90.6 3rd time 921.7 200 340 40.6 430 89.0 4th time 921.7 200 300 30.6 426 88.0 COMPARATIVE EXAMPLE 2 Into the same reactor as in example 8, 70% aqueous solution 746.3g of bismethochloride of bistss -(N,N-dimethyl¯ amino)ethyl]ether (522.4g of bismethochloride) and 1,080g of ethylenediamine were introduced and were subjected to a reaction at a reaction temperature 1600C and under a reaction pressure 3.5 - 4.5 kg/cm2 for 6 hours. After completion of the reaction, the reaction mixture was cooled to the room tem perature and was transferred to a separating funnel. The reaction mixture separated into two layers of upper and lower ones was taken out separately to recover 435g of the upper layer liquid and l,375g of the lower layer liquid. As a result of gas-chromatographic analysis of the upper layer, the existence of etheramine 277.7g was recognized. The recovered upper layer liquid was separated by distillation to recover 155g of low boiling point mixture having boiling points of not exceeding 1400C and etheramine. The lower layer liquid was transferred to a four neck flask made of glass equipped with a stirrer and a refluxing cooler and was added with 179g of solid sodium hydroxide. They were treated with stirring at a temperature of 60 - 900C for 4 hours. After leaving to stand, 1,245g of a supernatant liquid was recovered. As a result of gas-chromatographic analysis of this supernatant liquid, it was recognized that 11.6g of etheramine and 997g of a mixture of ethylendiamine with a mixture of N-methylated denatured compounds thereof were present. The total amount 1,400g of the low boiling mixture (155g) having boiling points of not exceeding 1400C recovered from the upper layer liquid and the supernatant liquid (1,245g) recovered from the lower layer as mentioned above was used as the demethylation agent in the second time reaction of producing etheramine. - To the upper layer liquid and lower layer liquid after the reaction of producing etheramine, the same separating and recovering procedures were applied and the repeated reactions were carried out three times1 employing the demethylation agent recovered from the reaction mixture of two layers of the upper and lower ones. The yield of etheramine was calculated in the same way as in example 8. The results of the repeated reaction were shown in Table 6. Table 6 No. of 70% aqueous addition NaOH etheramine repeti- solution of amount of concention bismetho- solid tration yield chloride (g) NaOH (g) (wt%) (g) (%) 1st time 746.3 179 6.4 289.3 89.8 2nd time 746.3 190 5.4 272.9 84.7 3rd time 746.3 190 3.7 246.5 76.5 EXAMPLE 10 Into the same reactor as in example 8, 1,258g of 70% aqueous solution of bismethochloride of bi -(N,N-dimethyl- amino)ethyl)ether (880.6g of bismethochloride) and 1,416g of ethylenediamine were introduced and were subjected to a reaction at a reaction temperature 1550C and under a reaction 2 pressure 2.5 v 3.5 kg/cm for 5 hours. The reaction mixture was taken out after cooled and was transferred to a four neck flask made of glass equipped with a stirrer, an inserting pipe of the thermometer and a refluxing cooler. Then, it was added with 694g of solid sodium hydroxide and treated with stirring at a temperature of 50 - 600C for 2.5 hours. From the solid phase sedimented toward the lower layer, 2,150g of a supernatant liquid was separated and recovered, and it was transferred to a distillation pot. With use of a column for distillation whose column height was 50 cm (filled with Raschig rings made of glass), the supernatant recovered liquid was subjected to a distillation under ordinary pressuer to give 1,655g of a distillate of column head temperature 90 - 1250C (fraction-I). As a result of practicing gas-chromatographi- SanÅalysis thereof 1 it was ascertained that, 1,480g of ethylenediamine and N-methylated ethylenediamines (the denatured compounds of ethylenediamine) was present. Subsequently, it was subjected to the reduced pressure distillation to give 456g of a distillate of column head temperature 1320C (165 mmHg) (fraction - II). As a result of gas-chromatographic analysis thereof 1 it could be ascertained that the fraction-II was bis[ss-(N,N -dimethylamino)ethyl]ether. The distillate of the fraction-I 1,655g was used as such in the second time reaction fdr producing etheramine. Performing the same separating and recovering procedures, the repeated reactions were carried out three times under the same condition. Without any additional supplement of ethylenediamine, only the recovered mixture of denatured"'copounds of ethylenediamine was used repeatedly. The results were shown in Table 7. Table 7 No. of 70% aqueous addition NaOH etheramine repeti- solution of amount of concention bismetho- solid tration yield chloride(g) NaOH (g) (wt%) (g) - (%) 1st time 1258 69 46.0 456 84,0 2nd time 1258 824 47.3 451 83.1 3rd time 1258 820 47.1 444 81.8 EXAMPLE 11 Into the same reactor as in example 8, l,300g of 73% aqueous solution of bismethochloride of bis[ss-(N,N-dimethyl- amino)ethyl)ether (949g of bismethochloride) and 1,884g of 1,3-propanediamine were introduced and were subjected to a reaction at a reaction temperature 1500C and under a reaction pressure 2 - 3 kg/cm2 for 7 hours. After the reaction, the reaction mixture was cooled and was added with 620g of solid sodium hydroxide through the opened cover of the reactor. After cover was closed again, it was heated with stirring at 70 - 900C for 2 hours. Then, 2,710g of a supernatant liquid was separated and recovered from the solid phase of the lower layer. Employing the same column for distillation as in example 10, the supernatant recovered liquid was subjected to a distillation under ordinary pressure to give 2,108g of a distillate of column head temperature 90 - 1800C (fraction - I). As a result of practicing gas-chromatographic analysis thereof, it was recognized that l,920g,of propanediamine and N-methylated propanediamines (the denatured compounds of propanediamine) was present. Subsequently, it was subjected to the reduced pressure distillation to give 513g of a distillate of column head temperature 1320C (160 mmHg) fraction - II). As a result of gas-chromatographic analysis thereof, there could be ascertained 509g of bis -(N,N-dimethylamino)ethyl) ether in the fraction-II; The distillate of the fraction-I 2,108g was used as such in the second time reaction for producing etheramine. Performing the same separating and recovering procedures, the repeated reactions were carried out four times. Without any additional supplement of propanediamine, only the recovered mixture of denatured compounds of propanediamine was used repeatedly. The results were shown in Table 8. Table 8 No. of 70% aqueous addition NaOH etheramine repeti- solution of amount of concention bismetho- solid tration yield chloride (g) NaOH (g) (wt%) (g) (%) 1st time 1300 620 40.6 509 87.0 2nd time 1300 690 37.0 496 84.9 3rd time 1300 730 38.6 486 83. 4th time 13Q0 710 35.0 476 81.4 COMPARATIVE EXAMPLE 3 Into the same reactor as in example 8, 1,000g of 70% aqueous solution of bismethochloride of bislp -(N,N-dimethyl- amino)ethyl)ether (7O0g of bismethochloride) and l,300g of ethylenediamine were introduced and were subjected to a reaction at a reaction temperature 150 C and under a reaction pressure 2.5 - 3.5 kg/cm2 for 7 hours. After the reaction, 249g of solid sodium hydroxide was added to the reaction mixture by the same procedure as in example 10, and it was heated with stirring at 70 - 800C for 3 hours. After leaving it to stand, 2,173g of a supernatant liquid was separated -and recovered from the solid phase of the lower layer. Employing the same column for distillation as in example 10, the supernatant recovered liquid was subjected to a distillation under ordinary pressure to give 1,785g of a distillate of column head temperature 90 - 1270C (fraction-I). As a result of gas-chromatographic analysis thereof, there could be ascertained 363g of bist -(N,N-dimethylamino)- ethyl)ether in the fraction-II. The distillate of fraction-I, 1,785g was used as such in the second time reaction for producing etheramine. The repeated reactions were likewise carried out three times. The results were shown in Table 9. Table 9 No. of 70% aqueous addition NaOH etheramine repeti- solution of amount of concention bismetho- solid tration yield chloride(g) NaOH (g) (wt%) (g) (%) 1st time 1000 249 8.1 363 84.1 2nd time 1000 280 8.0 333 77.2 3rd time 1000 309 8.0 310 71.9

Claims: WHAT IS CLAIMED IS: 1) A method for producing bis[ss-(N,N-dimethylamino)alkyl]ether by reacting a bismethohalide of a bis[ss-N,N-dimethyl- amino)alkyl]ether represented by the following general formula EMI40.1 wherein R and R' denote alkyl groups having 2 - 3 carbon atoms and X denotes halogen atom, with the aliphatic amine having a boiling point of 40 - 170 C at atmospheric pressure and having one or two primary amine group in the molecule thereof under an increased pressure. 2) The method for producing bist[ss-(N,N-dimethylamino)- alkyl]ether recited in claim 1, wherein the bismethohalide is the bismethochloride of bist-(N,N-dimethylamino)ethyl3- ether. 3) The method for producing bis[ss-(N,N-dimethylamino)alkyl] ether recited in claim 1, the aliphatic amine is butylamine, ethylenediamine, propanediamine or butanediamine. 4) The method for producing bis[ss-(N,N-dimethylamino)alkyl]- ether recited in claim 1, wherein the aliphatic amine is added by at least 2 mol to 1 mol of the bismethohalide. 5) The method for producing bisg -(N,N-dimethylamino)alkyl- ether recited in claim 1, wherein the reaction of the bismethohalide with the aliphatic amine is carried out at a temperature of 140 - 1900C. 6) The method for producing bis[ss-(NsN-dimethylamino)alkyl3 ether recited in claim 1, wherein the aliphatic amine is recovered from the reaction mixture and is reused in the repeated reaction. 7) The method for producing bis[ss-(N,N-dimethylamino)alkyl]- ether recited in claim 6, wherein the aliphatic amine is recovered by adding alkali compound to the reaction mixture, followed by neutralization and separation means. 8) A method for producing bis[ss-(N,N-dimethylamino)ethyl]ether wherein a bismethohalide compound of bistss -(N,N-dimethyl- amino)ethyl3ether represented by a general formula EMI41.1 (X denotes halogen atom) is reacted with an aliphatic amine1 which is characterized by comprising the following steps (a) (b) (c). (a) step of, separating and recovering an upper layer liquid and a lower layer liquid respectively from a reaction mixture having two separated upper a-nd lower layers obtained by the reaction of said bismethohalide compound with the aliphatic amine having primary or secondary amino group (b) step of adding alkali metal hydroxide to the lower layer liquid so as to be in a concentration of 10 55 weight% to water amount of the lower layer liquid, followed by recovering the aliphatic amine (c) step of further reusing the recovered aliphatic amine for the repeated reaction with said bis methohalide compound. 9) The method for producing bisLss-(N,N-dimethylamino)ethyl)- ether recited in claim 8, wherein the aliphatic amine has a boiling point of 40 - 1700C under an atmospheric pressure and has one or two primary amino group in the molecule thereof. 10) The method for producing bis6 -(N,N-dimethylamino)ethyl3- ether recited in claim 8, wherein the aliphatic amine is propylamine, butylamine, ethylenediamine, propanediamine or butanediamine. 11) The method for producing bi -(N,N-dimethylamino)ethyil - ether recited in claim 8, wherein alkali metal hydroxide is sodium hydroxide and/or potassium hydroxide. 12) A method for producing bilk -(N,N-dimethylamino)ethyl1- ether wherein bismethohalide compound of bisk -(N,N-dimethyl- amino)ethyl) ether represented by a general formula EMI42.1 (X denotes halogen atom) is reacted with an aliphatic amine having boiling point of 40 - 1700C under atmospheric pressure and having 1 - 2 primary amino group in the molecule thereof 1 which is characterized by comprising the following steps (a) (b) (c) (d). (a) step of adding alkali metal hydroxide so as to be 10 - 55 weights to water amount in'the reaction system, after completion of the reaction of said bismethohalide compound with said aliphatic amine (b) step of separating and recovering a liquid phase consisted of the amine (c) step of separating by distillation of the re covered amine into a distillate of boiling point of not exceeding 1700C and a distillate of that of exceeding 1700C (d) step of reusing the recovered amine having boiling point of not exceeding 1700C under atmospheric pressure in the repeated reaction with said bismethohalide. 13) The method for producing bi P-(N,N-dimethylamino)etY3 ether recited in claim 12, wherein the aliphatic amine is propylamine, butylamine, ethylenediamine, propane diamine or butenediamine. 14) The method for producing bis[ss-(N,N-dimethylamino)ethyl]- ether recited in claim 12, wherein alkali metal hydroxide is sodium hydroxide and/or potassium hydroxide.

Inventors: KEIJI, MITARAI, SADAKATSU, KUMOI, YUKIHIRO, TSUTSUMI
Applicants: TOYO SODA MANUFACTURING CO., LTD.
Application year: 1983
Main classification: C07C93