CN111689886A

CN111689886A - Preparation method of micro-channel of DMPT (dimethyl formamide PT)

Info

Publication number: CN111689886A
Application number: CN202010479844.4A
Authority: CN
Inventors: 邓维; 徐正阳
Original assignee: Shanghai Institute of Technology
Current assignee: Shanghai Institute of Technology
Priority date: 2020-05-30
Filing date: 2020-05-30
Publication date: 2020-09-22
Anticipated expiration: 2040-05-30
Also published as: CN111689886B

Abstract

The invention relates to a preparation method of a micro-channel of DMPT, which comprises the following steps: (1) pumping dimethyl sulfide aqueous solution and 3-bromopropionic acid aqueous solution into a microchannel reaction device for reaction, and obtaining brominated DMPT solution after the reaction is finished; (2) and separating the brominated DMPT solution to obtain the brominated DMPT crystal. Compared with the prior art, the method has the advantages of short reaction time, high selectivity and yield and the like.

Description

Preparation method of micro-channel of DMPT (dimethyl formamide PT)

Technical Field

The invention relates to the field of chemical synthesis, in particular to a preparation method of a micro-channel of DMPT.

Background

DMPT (S, S-dimethyl- β -thiothixene) natural product exists in marine phytoplankton, has different degrees of promotion effects on growth and ingestion of various sea and fresh water fishes and shrimps, can improve feed utilization rate and enhance resistance of fishes to adverse environment, and the DMPT exists in two modes, namely one mode is dimethyl- β -thiothixene hydrochloride, CAS (CAS) is 4337-33-1, and molecular formula C is C₅H₁₁SO₂Cl, molecular weight 170.66 Another is dimethyl- β -propiothiocetine hydrobromide, CAS: 20986-22-5, formula C₅H₁₁SO₂Br, molecular weight 216.12, the invention focuses on the latter. Because the natural extraction method for producing DMPT has high cost and low purity, and is inconvenient for industrialization, scientists focus on developing a method for artificially synthesizing DMPT.

The method for synthesizing DMPT in the prior art is to use dimethyl sulfide and 3-bromopropionic acid to react to obtain DMPT hydrobromide, but the reaction is very sensitive to temperature, and meanwhile, as the price of the 3-bromopropionic acid used as a substrate is very high, the traditional reaction kettle cannot well utilize the 3-bromopropionic acid to synthesize the DMPT with high efficiency.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a preparation method of DMPT microchannel with short reaction time, high selectivity and high yield.

The purpose of the invention can be realized by the following technical scheme:

the first object of the invention is to provide a set of microchannel reaction device, which comprises a first material tank for storing the dimethyl sulfide aqueous solution, a second material tank for storing the 3-bromopropionic acid aqueous solution, a micro-structure mixer, a microchannel reactor and a reactant storage tank.

The first charging bucket and the second charging bucket are respectively connected with the microstructure mixer to form two branches; the micro-structure mixer, the micro-channel reactor and the reactant storage tank are connected in sequence.

Further, the micro-mixer is slitplatmixer LH25 (HastelloyC); purchased from Ehrfeld Mikrotechnik BTS GmbH, model 0109-4-0004-F; the microchannel reactor is a meaanderreactor HC, a sandwich actor HC and a fixed bed meanger actor HC; preferably sandwichureactor HC, available from Ehrfeld Mikrotechnik BTS GmbH, and having models of 0211-2-0314-F and 0222-2-2004-F, respectively; the temperature control module in the microchannel reactor is purchased from Ehrfeld Mikrotechnik BTS GmbH and has the model of 0501-2-1004-F.

The microchannel reactor is used as an efficient modular reactor, and is widely applied to chemical production in various fields nowadays. The microchannel reactor has the advantages of small size, modularization, small specific surface area, good heat and mass transfer effects, and high-efficiency heat exchange between reactants in the microchannel and the wall surface, so that the reaction temperature can be accurately controlled, the thermal efficiency problems of local overheating, supercooling, uneven heat transfer and the like in the reaction can be effectively avoided, some side reactions can be avoided, the synthesis of set target products can be more facilitated, and the reaction selectivity can be improved.

The second purpose of the invention is to provide a method for preparing a micro-channel of DMPT, which comprises the following steps:

(1) pumping dimethyl sulfide aqueous solution and 3-bromopropionic acid aqueous solution into a microchannel reaction device for mixing and reacting to obtain brominated DMPT solution after the reaction is finished;

(2) and separating the brominated DMPT solution to obtain the brominated DMPT crystal.

Further, the specific steps of the step (1) are as follows:

(1-1) pumping the dimethyl sulfide aqueous solution in the first material tank and the 3-bromopropionic acid aqueous solution in the second material tank into a micro-structure mixer, and uniformly mixing;

(1-2) introducing the mixed liquid into a microchannel reactor for reaction, introducing a brominated DMPT solution obtained after the reaction into a reactant storage tank, wherein the reaction formula is as follows:

(CH₃)₂S+Br(CH₂)₂COOH→[(CH₃)₂S⁺CH₂CH₂COOH]Br^-

further, the reaction temperature of the mixed liquid in the microchannel reactor is 35-50 ℃.

Further, the reaction temperature of the mixed liquid in the microchannel reactor is 40 ℃.

Further, the reaction retention time of the mixed liquid in the microchannel reactor is 5-10 h.

Further, the reaction retention time of the mixed liquid in the microchannel reactor is 8-10 h.

Further, the diameter of the microchannel reactor is 1-2mm, and the volume is 100-200 ml.

Furthermore, the concentration of the dimethyl sulfide aqueous solution is 4-5mol/L, and the concentration of the 3-bromopropionic acid aqueous solution is 4-5 mol/L.

Furthermore, the volume ratio of the dimethyl sulfide aqueous solution to the 3-bromopropionic acid aqueous solution is (1-2) to 1 during mixing.

Further, the specific steps of the step (2) are as follows: and (3) standing the brominated DMPT solution for precipitation, washing the obtained precipitated solid with glacial ethyl ether, and finally recrystallizing with a methanol solution to obtain the brominated DMPT crystal.

Compared with the prior art, the invention has the following advantages:

(1) the invention utilizes the microchannel reaction device with good mass transfer effect to ensure that the reaction time is shorter;

(2) the yield of the DMPT continuous production of the invention is superior to the prior art.

Drawings

FIG. 1 is a schematic diagram of a synthesis apparatus according to the present invention;

the reference numbers in the figures indicate: the device comprises a first charging bucket 1, a second charging bucket 2, a microstructure mixer 11, a microchannel reactor 22 and a reactant storage tank 3.

Detailed Description

The invention is described in detail below with reference to the figures and specific embodiments.

Example 1

The microchannel reactor apparatus in this embodiment, as shown in fig. 1, includes a first tank 1 for storing an aqueous dimethyl sulfide solution, a second tank 2 for storing an aqueous 3-bromopropionic acid solution, a micro-mixer 11, a microchannel reactor 22, and a reactant storage tank 3. The first charging bucket 1 and the second charging bucket 2 are respectively connected with the microstructure mixer 11 to form two branches; the micro-structure mixer 11, the micro-channel reactor 22 and the reactant reservoir 3 are connected in sequence.

Wherein the micro-mixer 11 is slitplatmixer LH25 (HastelloyC); purchased from Ehrfeld Mikrotechnik BTS GmbH, model 0109-4-0004-F; the microchannel reactor 22 is a sandwichreactor HC, available from Ehrfeld Mikrotechnik BTS GmbH, model number 0211-2-0314-F, diameter 1.5mm, volume 150 ml; the temperature control module in the microchannel reactor 22 is available from Ehrfeld Mikrotechnik BTSGmbH, model 0501-2-1004-F.

A method for preparing a microchannel of DMPT, the method comprising the steps of:

(1-1) pumping dimethyl sulfide aqueous solution with the concentration of 5mol/L in the first charging bucket 1 and 3-bromopropionic acid aqueous solution with the concentration of 4mol/L in the second charging bucket 2 into a micro-structure mixer 11, and uniformly mixing according to the volume ratio of 1: 1, wherein;

(1-2) introducing the mixed liquid into a microchannel reactor 22 for reaction, and introducing a brominated DMPT solution obtained after the reaction into a reactant storage tank 3, wherein the reaction temperature is 40 ℃, and the reaction retention time is 8 h. The reaction formula is as follows:

(CH₃)₂S+Br(CH₂)₂COOH→[(CH₃)₂S⁺CH₂CH₂COOH]Br^-

(2) and (3) standing the brominated DMPT solution for precipitation, washing the obtained precipitated solid with glacial ethyl ether, and finally recrystallizing with a methanol solution to obtain the brominated DMPT crystal.

Comparative example 1

The difference from example 1 is that this example uses a direct chemical approach to DMPT synthesis.

Example 2

The difference from example 1 is that the volume ratio of the aqueous dimethyl sulfide solution to the aqueous 3-bromopropionic acid solution is 1.5: 1.

Comparative example 2

The difference from example 2 is that this example uses a direct chemical approach to DMPT synthesis.

Example 3

The difference from example 1 is that the volume ratio of the aqueous dimethyl sulfide solution to the aqueous 3-bromopropionic acid solution is 2: 1.

Comparative example 3

The difference from example 3 is that this example uses a direct chemical approach to DMPT synthesis.

Example 4

The difference from example 1 is that the reaction temperature is 35 ℃ and the volume ratio of the aqueous dimethyl sulfide solution to the aqueous 3-bromopropionic acid solution is 1.5: 1.

Comparative example 4

The difference from example 4 is that this example uses a direct chemical approach to DMPT synthesis.

Example 5

The difference from example 1 is that the reaction temperature is 45 ℃ and the volume ratio of the aqueous dimethyl sulfide solution to the aqueous 3-bromopropionic acid solution is 1.5: 1.

Comparative example 5

The difference from example 5 is that this example uses a direct chemical approach to DMPT synthesis.

Example 6

The difference from example 1 is that the reaction temperature is 50 ℃ and the volume ratio of the aqueous dimethyl sulfide solution to the aqueous 3-bromopropionic acid solution is 1.5: 1.

Comparative example 6

The difference from example 6 is that this example uses a direct chemical approach to DMPT synthesis.

Example 7

The difference from example 1 is that the reaction retention time is 5h and the volume ratio of the aqueous dimethyl sulfide solution to the aqueous 3-bromopropionic acid solution is 1.5: 1.

Comparative example 7

The difference from example 7 is that this example uses a direct chemical approach to DMPT synthesis.

Example 8

The difference from example 1 is that the reaction retention time is 10h and the volume ratio of the aqueous dimethyl sulfide solution to the aqueous 3-bromopropionic acid solution is 1.5: 1.

Comparative example 8

The difference from example 8 is that this example uses a direct chemical approach to DMPT synthesis.

Compared with the method using a microreactor, the method using the same raw materials for synthesizing DMPT by the direct chemical method has the advantages that the yield is generally lower than that of the microreactor, the requirement of industrial continuous production cannot be met by the direct chemical method compared with the microreactor, the reaction conditions can be controlled more easily when the microreactor is used for preparing DMPT, the reaction can be stably and continuously synthesized under constant conditions, and the requirement of industrial production is met. In addition, the flow rate of the reaction substrate can be controlled, so that the control of the production scale of the product in industrial production is achieved, and the specific data are shown as follows:

the DMPT conversion for each example is shown in table 1.

TABLE 1

The DMPT conversion for each comparative example is shown in Table 2.

TABLE 2

The embodiments described above are described to facilitate an understanding and use of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should understand that they can make various modifications, changes, substitutions, combinations, and the like equivalent to the embodiments without departing from the scope of the present invention.

Claims

1. A method for preparing a microchannel of DMPT, the method comprising the steps of:

2. The method for preparing the micro-channel of DMPT of claim 1 wherein the specific steps of step (1) are:

(1-1) pumping the dimethyl sulfide aqueous solution in the first charging bucket (1) and the 3-bromopropionic acid aqueous solution in the second charging bucket (2) into a micro-structure mixer (11) and uniformly mixing;

(1-2) introducing the mixed liquid into a microchannel reactor (22) for reaction, and introducing a brominated DMPT solution obtained after the reaction into a reactant storage tank (3).

3. The method of claim 2, wherein the mixed liquid is reacted in the microchannel reactor (22) at a temperature of 35-50 ℃.

4. The method of claim 3, wherein the mixed liquid is reacted in the microchannel reactor (22) at a temperature of 40 ℃.

5. The method of claim 2, wherein the mixed liquid has a reaction retention time of 5-10h in the microchannel reactor (22).

6. The method of claim 5, wherein the mixed liquid has a reaction retention time of 8-10h in the microchannel reactor (22).

7. The method as claimed in claim 2, wherein the diameter of the microchannel reactor (22) is 1-2mm, and the volume is 100-200 ml.

8. The method of claim 1, wherein the concentration of the dimethyl sulfide aqueous solution is 4-5mol/L, and the concentration of the 3-bromopropionic acid aqueous solution is 4-5 mol/L.

9. The method of claim 1, wherein the volume ratio of the dimethyl sulfide aqueous solution to the 3-bromopropionic acid aqueous solution is (1-2): 1.

10. The method for preparing the micro-channel of DMPT of claim 1 wherein the specific steps of step (2) are: and (3) standing the brominated DMPT solution for precipitation, washing the obtained precipitated solid with glacial ethyl ether, and finally recrystallizing with a methanol solution to obtain the brominated DMPT crystal.