JPH03220134A - Continuous production of organic compound accompanying exothermic reaction - Google Patents

Abstract

PURPOSE:To remove reaction heat by latent heat in evaporation by separately and continuously feeding two or more kinds of raw materials to main part of reaction in the presence of a solvent, bringing these raw materials into contact with each other for a short time to react these raw materials and introducing the reaction mixture into a subsidiary reaction part having a larger volume and a lower pressure than main part of reaction. CONSTITUTION:The inside of a reaction device 4 is kept at 40mmHg pressure and a cyclohexane solution of PCl3 and n-propyl alcohol are cooled to -5 to -4 deg.C, each fed from lines 1 and 2 to a static mixer 3 with 6 stages, and the cyclohexane solution is brought into contact with n-propyl alcohol for 0.4sec. The reaction mixture is scattered in atomized state because of a reduced pressure of the reaction device and dropped along a device wall by a direct drop- preventing umbrella (temperature sensor 16 is -2 deg.C). The evaporated solution is passed through a line 11 and entered a receiver 15 and product is entered a receiver 10. The reaction mixture may be dropped inside a spiral pipe. Thereby reaction heat is quickly removed and subsidiary reaction is suppressed, and the objective product can be inexpensively obtained in good yield.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a continuous organic compound that can be used more effectively even for reactions that have a very high reaction rate or a large amount of reaction heat per unit time. Regarding the manufacturing method.

[Conventional technology]

To control the reaction by removing the heat of reaction, a coil is placed inside the reaction system and a refrigerant is passed through the coil to cool it, or a refrigerant is passed through the external jacket of the reaction system to remove the heat of reaction and control the reaction. There are known methods for controlling the temperature and for cooling the reaction system by using a pump to circulate the liquid within the reaction system within an external cooler in order to increase the cooling area.

[Problem to be solved by the invention]

In the method of directly cooling the reaction system, the cooling area per unit volume is insufficient to maintain the reaction temperature, so it is necessary to lower the concentration per unit volume for the reaction. As a result, not only fixed costs increase due to decreased production capacity, but also the amount of solvent recovered per product increases, and it costs a lot of money to collect, refine and reuse the solvent, or dispose of it as industrial waste. It costs a lot of money. It is not an industrially economical method.

However, the temperature increases not only at the connecting piping between the reaction system and the cooling system, but also within the reaction system due to the reaction heat, creating an unacceptable temperature difference between the reaction system and the cooling system, resulting in a decrease in yield. This is not an industrially economical method because it is a major cause of deterioration in product quality.

[Means to solve the problem]

In order to carry out the reaction at an economical concentration per unit volume while maintaining the desired temperature, it is necessary to increase the heat removal rate and heat removal capacity.

The present inventors have discovered a method of removing reaction heat and causing a reaction using the latent heat of vaporization of a solvent. In other words, Boyleschard's law: PV/T = constant (however, in this formula, P is the pressure unit at
m:V is the unit of volume t.

T is in absolute temperature units °. ) The present invention was achieved by utilizing the fact that in a system where V (volume) is constant, pressure and temperature are inversely proportional and are governed by the gas-liquid ratio in a given solvent.

That is, in the present invention, two or more raw material compounds are separately and continuously fed to a main reaction part in the presence of a solvent, brought into contact for a short time to react, and then the reaction mixture is transferred to a reactor with a volume smaller than that of the main reaction part. The present invention relates to a method for continuously producing an organic compound accompanied by an exothermic reaction, which is characterized by discharging the solvent into a side reaction section (reaction tank) with low pressure and removing the reaction heat using the latent heat of vaporization of the solvent.

According to the present invention, it is a very effective method for increasing the heat removal rate and heat removal capacity.

Taking the case of a water-soluble reaction as an example, the latent heat of vaporization per about 1000 g of water is about 54 Q kcal. This value corresponds to the amount of heat equivalent to raising about 1,000 g of water by about 540°C, and the heat removal rate is also very fast, making it easy to control the temperature of the reaction.

The present invention will be explained in detail below.

Examples of exothermic reactions that can be used in the present invention include the following reactions, but the present invention is not limited thereto.

Reactions for producing iminoether compounds from nitriles and alcohols in the presence of hydrochloric acid, reactions for producing phosphite compounds from trihalogenated phosphorus and alcohols, reactions for producing amide compounds from diketenes and amines, free sol fluoride Reaction salt Decomposition reaction of aluminum complex, reaction of adding halogen to olefin to produce dihalo compound, neutralization reaction of non-acid and inorganic base, addition reaction of carbenes,
A reaction that produces phosphoric acid esters by reacting phosphoric acid chloride with phenols.

Reactions to produce carboxylic acid esters by reacting carboxylic acid chlorides with alcohols or phenols, decomposition of peroxides, reactions to produce aminohydrins or halohydrins by reacting epoxides with amines or hydrogen halides, addition of radicals, or Substitution reaction, reaction of reacting amines or anilines with hydrogen halides to produce ammonium halides, reaction of reacting hydroxylamine with carboxylic acid ester to produce hydroxamic acid, reaction of reacting nitriles with alcohols to produce iminoethers reaction to produce amidine by reacting iminoether with amines, reaction to produce dichlorocyclopropane by reacting chloroform and olefin, and production of polyacrylic ester by polymerizing acrylic ester. reaction, a reaction in which a carboxylic acid chloride and an amine are reacted to produce a carboxylic acid amide, and a reaction in which a trialkyl phosphite is reacted with a 2-chloroketone to produce a phosphoric acid ester.

The reaction solvent that can be used in the present invention is preferably a suitable solvent that evaporates at a predetermined pressure and temperature and does not inhibit the reaction, such as water; alcohols such as methanol, ethanol, gropanol, and cyclohexanol; acetone; Ketos such as methyl ethyl ketone cyclohexanone; Esters such as methyl acetate and ethyl acetate; Aliphatic hydrocarbons such as hexane, cyclohexane, heptane, carbon tetrachloride, 1-chloro-pentane, and 1,2-dichloropropane: benzene, toluene , aromatic hydrocarbons such as xylene, monochlorobenzene, p-chlorotoluene + N.

Examples include, but are not limited to, amides such as N-dimethylformamide and N-methylacetamide; dimethylsulfoxide; 2-pyrrolidone; and sulfolane.

Next, the method of the present invention will be explained using the following reaction example.

P CI3 + 3 C1h Cl12 CH20H→
(CH3CH2CH20)2 P OH+CH3CH2
CH2CI + 2 HC1 The heat of reaction at this time is approximately 48
Kca is 11 mol, and side reactions such as polymerization reactions occur rapidly at high temperatures, so it is very important to keep and control the reaction temperature at a low temperature. That is, an industrially practical solvent concentration, for example, a raw material concentration of phosphorus trichloride, 100ml of cyclohexane, 11 moles, and n-propyl alcohol (undiluted) are each used at an initial liquid temperature of 0°C, and a spherical shape with a diameter of about 2rnM is placed inside. For a reaction in a glass tube with a diameter of about 8 rEIR filled with beads, the specific heat is 0.6 cal/g, 'C, the specific gravity is 0.93 g/ml (-5 °C), and the heat capacity of the tube and packing is If we ignore this and assume that heat radiation is also ignored, the liquid temperature will be approximately 113°C.

Therefore, the present inventors tried a cooling method using liquid nitrogen, but it was extremely difficult to recover the solvent that was scattered along with the nitrogen gas, and the amount of liquid nitrogen consumed was large, making it impractical to use as an industrial method. I didn't get it.

The invention can be carried out using, for example, a reaction apparatus as shown in FIG. 11 on the jacket of condenser 12 in advance
Brine at 5±2° C. is passed through the reactor 4 and adjusted using a vacuum pump or the like through a line 14 so that the inside of the reactor 4 reaches a predetermined pressure. Next, add 1 and 2 raw materials to a cyclohexane solution and a n-pyl alcohol solution of phosphorus trichloride, respectively.
! I7.2+, W is used to send the liquid to the static mixer 3 using a liquid sending pump, and the mixture is mixed to start the reaction. The liquid that has passed through the reactor 3 is flushed to the reactor 4, and is brought into a vapor-liquid equilibrium state where the liquid reaches a predetermined temperature and a predetermined pressure at the same time. Note that the temperature is displayed by a temperature sensor 16. When the temperature rises above the temperature at a predetermined pressure due to the heat of reaction, it is instantaneously cooled down by the latent heat of vaporization of the solvent. The evaporated solvent passes through line 11 and is cooled and condensed in condenser 12.
It passes through line 13 and enters receiver 15. -1 mixed liquid reacts and falls down the internal machine wall of 4 by a direct fall prevention vehicle 5 fixed to 4 by supports 7 and 8.

The role of the direct drop prevention vehicle 5 is important, and is to prevent as much as possible the phosphite produced by the reaction from mixing with each raw material and causing side reactions; The goal is to prevent For this purpose, it is also possible to use a spiral pipe 19 with an umbrella 18 for a liquid receiver with an appropriate hole 17 in the top or side to maintain equal pressure, as shown in Fig. 2. This is an effective method. However, the present invention is not limited to these.

The molar ratio of n-propylamine to phosphorus trichloride, which is the raw material of the present invention, is usually 0.90 to 1.20, preferably 1.
．． It is preferable to use 00 to 1.07.

The reaction temperature is maintained at -10°C to +15°C, preferably -7°C to 0°C, by latent heat of vaporization, and if necessary, further cooled, for example, from the outside or inside of the reactor 4 in Figure 1. It can be controlled. It is preferable to mix both raw materials as quickly as possible, and a line mixer method or a spray nozzle method is a good method. As the line mixer, for example, the static mixer 3 shown in FIG. 1 or a forced stirring type line mixer can be used.

Also, regarding the spray nozzle method, it is preferable to use one that focuses on mixing both liquids in a short time. The hindlimb mixture is transferred to a reactor with the pressure system described below and is cooled using the latent heat of vaporization of the solvent. However, in the case of the present invention, the pressure is not limited to the reaction between phosphorus trichloride and normal propyl alcohol. , usually 0.5 mmHg ~ 760
mmHg. A lower pressure is preferable because it allows for a low-temperature reaction, but from the point of view of recovering the solvent, there is a problem if the pressure is too low, so a range of 10 to 400 mm/g is practically preferable.

Further, in the present invention, most of the reaction occurs in the main reaction section 3 (for example, a static mixer), and the reaction time here is preferably adjusted to 0.1 to 10 seconds.

Further, although it is advantageous to use a large amount of solvent in terms of control of reaction conditions and yield, it is preferable to use a small amount of solvent in consideration of recycling of the solvent used.

The total amount of solvent for phosphorus trichloride is, for example, 2.00 to 5.00
0m11 mole, preferably 300 to 1.000m1
It is 1 mole.

The reaction completed ff1O,0 di-n-propyl phosphorite (I) can be manufactured into a product by recovering the solvent by a conventional method, for example, under reduced pressure, and then precision distilling under reduced pressure.

〔Effect of the invention〕

The method of the present invention is a method that quickly removes the reaction heat with a large calorific value, suppresses side reactions, and can industrially produce compounds at high yields and at low cost.

The present invention will be explained below with reference to Examples.

[Example] Using the apparatus shown in FIG. 1, a vacuum pump was operated through the line 14 so that the pressure inside the reactor 4 was approximately 40 mmHg. Next, a solution of 20 mol of phosphorus trichloride dissolved in 6,000 ml of cyclohexane and 6 ml of n-propyl alcohol were added.
Each of the 3 mol liquids was cooled to -5 to -4°C, and sent to the 6-stage static mixer 3 through the raw material introduction pipes 1.2 and 3 using a liquid feeding pump so that they each flowed at an increased speed in about 5 minutes. It liquefied.

The equilibrium contact time in 3 is about 0.4 seconds, and the liquid that has passed through 3 is dispersed in the form of a mist due to the reduced pressure in the reactor 4, and directly falls down the wall of the 40 machine by the fall prevention vehicle 5. 16 temperature sensors were approximately -2°C.

The reaction product was sent to 10 reaction liquid receivers and subjected to gas chromatography analysis, and the pure amount was 3.1 s 7 g (95% pure yield based on phosphorus trichloride).

[Comparative example]

20 mol of phosphorus trichloride and 6 cyclohexane in a 2OA reactor
．． 000 ml was charged, the outer jacket was cooled with grain at a temperature of about -13°C, and normal propyl alcohol cooled to -5°C was added dropwise to maintain the internal temperature at -2°C due to cooling rate control. It took about 50 minutes.

Gas chromatography analysis revealed that the reaction product had a pure amount of 2923 g (88% pure yield).

[Brief explanation of drawings]

FIG. 1 is an example of a reactor and a flowchart used in one embodiment of the present invention. FIG. 2 shows an example of a reactor in which a spiral pipe with an umbrella is used as the liquid receiver instead of the umbrella shown in FIG. 1... Raw material introduction pipe, 2... Raw material introduction pipe, 3... Static mixer 4... Reactor, 5... Umbrella,
61. . Line, 7...Supporter-8...Supporter-9...
- Stirrer, 10... Reaction liquid receiver, 11... Line,
12... Capacitor 13... Line, 14...
・Line, 15... Receiver, 16... Temperature sensor
17...hole, 18...liquid receiver is umbrella, 19...spiral pipe

Claims (5)

[Claims] (1) Two or more raw material compounds are each fed separately and continuously to the main reaction part in the presence of a solvent, brought into contact for a short time to react, and then the reaction mixture is transferred to a reactor with a larger volume and a lower pressure than the main reaction part. A method for continuous production of organic compounds accompanied by an exothermic reaction characterized by discharging the solvent into a low-temperature side reaction section (reaction tank) and removing the reaction heat using the latent heat of vaporization of the solvent. (2) The manufacturing method according to claim (1), wherein the reaction time in the main reaction section is adjusted to 0.1 to 10 seconds. (3) Reaction pressure in the main reaction section from 0.5 to 760 mm
The manufacturing method according to claim (1), in which Hg is adjusted. (4) Claims (1), (2), or (3) characterized in that the reaction is carried out while falling down the machine wall in order to prevent mixing of unreacted raw materials and reaction products as much as possible. Section method. (5) Claim No. (1), (2) or (3) characterized in that the reaction is carried out while falling in a spiral in order to prevent mixing of unreacted raw materials and reaction products as much as possible. Method.