RU2850965C1 - Method for obtaining 2,2'-dimorpholinodiethyl ether - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to a method for producing 2,2'-dimorpholinodiethyl ether (DMDEE), which is used as a catalyst for curing polyurethane foams and is also used in organic synthesis. The method is characterised in that 2,2'-dichloro diethyl ether and morpholine are mixed in an autoclave in a molar ratio of 1:4 to 1:6 and the synthesis is carried out at 160-200 °C for 6-18 hours. The reaction mixture is then cooled, the precipitate is filtered and washed with cyclohexane. The technical product is then distilled under vacuum to obtain DMDEE.

EFFECT: provision of a one-stage method for obtaining the target product under mild conditions with a yield of more than 90% and a purity of more than 99%.

8 cl, 1 dwg, 2 tbl, 3 ex

Description

Field of technology

The invention relates to a method for producing 2,2'-dimorpholinodiethyl ether (DMDEE), which is used as a catalyst for curing polyurethane foams and is also used in organic synthesis.

State of the art

2,2'-Dimorpholinodiethyl ether (DMDEE) is a one-component polyurethane foaming catalyst and is used in the fields of polyurethane coatings, adhesives, hot-melt adhesives, foam sealants, cementitious grouting materials, urban rail transport materials, etc.

A method for the joint production of 2,2'-dimorpholinodiethyl ether and hydroxyethoxyethylmorpholine is known from the prior art, comprising the reaction of diethylene glycol and morpholine in the presence of hydrogen over a catalyst selected from the group consisting of copper, cobalt on amorphous silica and cobalt on aluminum oxide [EP 0716084].

A method for producing 2,2'-dimorpholinodiethyl ether is known, in which 2,2'-dimorpholinodiethyl ether is obtained by reacting diethylene glycol with ammonia under pressure at an elevated temperature in the presence of hydrogen [DE 19901198 A1].

A method for synthesizing dimorpholinodiethyl ether is known, which includes the step of preparing a copper-based catalyst twice modified with an alkaline earth metal and silver, and also using morpholine and diethylene glycol as feedstock [CN 116425702 B].

Despite the availability of various approaches to the production of 2,2'-dimorpholinodiethyl ether, there remains a need to develop new methods with improved efficiency.

Disclosure of invention

The objective of the present invention is to develop a new and efficient method for synthesizing 2,2'-dimorpholinodiethyl ether.

The stated problem is solved by implementing a method for obtaining 2,2'-dimorpholinodiethyl ether, which includes the following steps:

a) mixing 2,2'-dichlorodiethyl ether and morpholine in a molar ratio of 1:4 to 1:6 in an autoclave;

b) heating the reaction mixture obtained in step a) to a temperature of 160-200°C;

c) holding and stirring the reaction mixture after step b) for 6-18 hours;

d) cooling the reaction mixture after step c), filtering the precipitate and washing it with cyclohexane;

d) vacuum distillation of technical 2,2'-dimorpholinodiethyl ether after filtration of the precipitate in step d) to obtain the target 2,2'-dimorpholinodiethyl ether.

In particular embodiments of the invention, heating in step b) is carried out in an oil bath.

In particular embodiments of the invention, vacuum distillation at stage d) is carried out at a temperature of 120-122°C and 0.8 mm Hg.

In particular embodiments of the invention, after filtration at step d), morpholine and cyclohexane are distilled from the filtrate under vacuum in a water bath heated to boiling.

In particular embodiments of the invention, the precipitate in step d) is morpholine hydrochloride.

In particular embodiments of the invention, the temperature at step b) is 180°C.

In particular embodiments of the invention, at step c), the reaction mixture is held and stirred for 8 hours.

In particular embodiments of the invention, cooling at stage g) is carried out to a temperature of 20-30°C.

As a result of implementing the invention, the following technical results are achieved:

- a new and efficient method for obtaining 2,2'-dimorpholinodiethyl ether has been developed, which is carried out in one stage and is also characterized by a high yield (more than 90%) and content (more than 99%) of the target product;

- the method according to the invention is a single-stage process that provides reliable results and is carried out under mild conditions using equipment without high pressure;

- the method according to the invention ensures a virtually complete conversion of the initial 2,2'-dichlorodiethyl ether into 2,2'-dimorpholinodiethyl ether;

- the method according to the invention expands the arsenal of available means for obtaining 2,2'-dimorpholinodiethyl ether.

Detailed disclosure of the invention

Brief description of the drawings

Figure 1. Block diagram of the stages of the technological process of the method according to the invention.

Definitions (terms)

For a better understanding of the present invention, certain terms used in this description of the invention are provided below. The following definitions apply throughout this document unless otherwise specified.

In the description of this invention, the terms "includes" and "comprising" are interpreted to mean "includes, among other things." These terms are not intended to be construed as meaning "consists solely of."

Also here, listing numeric ranges by endpoints includes all numbers within that range.

2,2'-dimorpholinodiethyl ether (DMDEE) is characterized by the following structural formula:

Implementation of the invention

A method for producing 2,2'-dimorpholinodiethyl is proposed, which includes the following steps:

1. Loading raw materials into the autoclave – morpholine and 2,2'-dichlorodiethyl ether.

2. Heating and holding of reagents.

3. Filtration and washing of the resulting precipitate of morpholine hydrochloride.

4. Distillation of the technical product to obtain DMDEE with a purity of more than 99%.

The present invention is explained by specific examples of implementation, which are not the only possible ones or limiting the invention in any way, but clearly demonstrate the possibility of achieving the claimed technical result.

Materials and equipment

Table 1

Raw materials Morpholine CAS No. 110-91-8
A colorless, hygroscopic liquid with a slight amine-like fishy odor.
Purity - %
Molar mass – 87.1 g/mol 2,2'-dichlorodiethyl ether CAS No. 111-44-4
White powder
Purity - %
Molar mass: 143.01 g/mol Cyclohexane CAS No. 110-82-7
A colorless liquid with a specific odor of petroleum products
Purity – 99.7%
Molar mass: 84.16 g/mol

Example 1

An autoclave equipped with an oil bath is charged with 15 g of 2,2'-dichlorodiethyl ether and 46.5 g of morpholine. The oil bath is heated to 180°C and the reaction mixture is maintained with stirring for 8 hours. After this time, the reaction mixture is cooled to 20-30°C, and the formed precipitate (morpholine hydrochloride) is filtered off and washed with 100 ^cm3 of cyclohexane. Morpholine and cyclohexane are distilled from the filtrate under vacuum in a water bath heated to boiling. The resulting technical product DMDEE is distilled under vacuum, the distillation temperature is 120-122°C at a vacuum of 0.8 mmHg, to obtain the target DMDEE. Yield is 96%.

Example 2

An autoclave equipped with an oil bath is charged with 15 g of 2,2'-dichlorodiethyl ether and 40 g of morpholine. The oil bath is heated to 180°C and the reaction mixture is maintained with stirring for 8 hours. After this time, the reaction mixture is cooled, and the resulting precipitate (morpholine hydrochloride) is filtered off and washed with 100 ^cm3 of cyclohexane. Morpholine and cyclohexane are distilled from the filtrate under vacuum in a water bath heated to boiling. The resulting technical product, DMDEE, is distilled under vacuum at a distillation temperature of 120-122°C under a vacuum of 0.8 mmHg to obtain the target DMDEE. Yield: 91%.

Example 3

An autoclave equipped with an oil bath is charged with 15 g of 2,2'-dichlorodiethyl ether and 46.5 g of morpholine. The oil bath is heated to 160°C and the reaction mixture is maintained with stirring for 8 hours. After this time, the reaction mixture is cooled, and the formed precipitate (morpholine hydrochloride) is filtered off and washed with 100 ^cm3 of cyclohexane. Morpholine and cyclohexane are distilled from the filtrate under vacuum in a water bath heated to boiling. The resulting technical product, DMDEE, is distilled under vacuum at a distillation temperature of 120-122°C under a vacuum of 0.8 mmHg to obtain the target DMDEE. Yield: 92%.

After distillation, morpholine and cyclohexane can be reused.

The obtained product is 2,2'-dimorpholinyl diethyl ether, its characteristics are presented in Table 2.

Table 2

Name of the indicator Meaning Appearance and color Transparent liquid without mechanical impurities from yellow to amber color Mass fraction of the main substance, %, not less than 99.0 Mass fraction of water, %, not more than 0.1 Content of amino groups, mg-eq/g 8.1-8.5 Pour point, °C, not higher -28 Density at 20°C, g/ ^cm3 1.05-1.10 Kinematic viscosity at 15°C, cSt 25-30

Using elevated process temperatures and performing the process in a closed vessel/autoclave (i.e., under the pressure of the reactants' own vapors) results in complete conversion of dichlorodiethyl ether (the main feedstock) and reduces waste. Thus, the inventive method represents a single-stage process for obtaining the target product with a high yield.

Although the invention has been described with reference to the disclosed embodiments, it will be apparent to those skilled in the art that the specific experiments described in detail are provided merely for the purpose of illustrating the present invention and should not be construed as limiting the scope of the invention in any way. It should be understood that various modifications are possible without departing from the spirit of the present invention.

Claims (13)

1. A method for producing 2,2'-dimorpholinodiethyl ether, comprising the following steps: a) mixing 2,2'-dichlorodiethyl ether and morpholine in a molar ratio of 1:4 to 1:6 in an autoclave; b) heating the reaction mixture obtained in step a) to a temperature of 160-200°C; c) holding and stirring the reaction mixture after step b) for 6-18 hours; d) cooling the reaction mixture after step c), filtering the precipitate and washing it with cyclohexane; d) vacuum distillation of technical 2,2'-dimorpholinodiethyl ether after filtration of the precipitate in step d) to obtain the target 2,2'-dimorpholinodiethyl ether. 2. The method according to claim 1, wherein heating in step b) is carried out in an oil bath. 3. The method according to claim 1, wherein the vacuum distillation in step d) is carried out at a temperature of 120-122°C and 0.8 mm Hg. 4. The method according to paragraph 1, in which after filtration in step d), morpholine and cyclohexane are distilled from the filtrate under vacuum in a water bath heated to boiling. 5. The method according to claim 1, wherein the precipitate in step d) is morpholine hydrochloride. 6. The method according to claim 1, wherein the temperature in step b) is 180°C. 7. The method according to claim 1, wherein in step c) the holding and stirring of the reaction mixture is carried out for 8 hours. 8. The method according to claim 1, wherein cooling in step d) is carried out to a temperature of 20-30°C.