JPS6267062A - Purification of crude liquid organosulfonyl chloride - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process for removing impurities from crude liquid organosulfonyl chloride in a two-step operation, preferably continuously. The crude liquid product is first subjected to a scrubbing operation with clean aqueous hydrochloric acid to remove organosulfonic acids, and then the cleaned (acrubb@d) product is subjected to vacuum stripping to remove e.g. mercaptans,
Volatile components including chlorine, sulfide, and water are vaporized by blowing away the volatile components with an inert gas (Ilw・ep).
) Immediately remove the vapors generated during the IJ lapping operation.

High purity organosulfonyl chloride is required because applications of organosulfonyl chloride products often do not tolerate impurities. Organosulfonyl chlorides are used, for example, in the production of cotton fibers, pharmaceutical substances such as steroids, and general pharmaceuticals. Organosulfonyl chlorides are also used in the production of some large-scale products that are sensitive to acid by-products, such as the production of herbicides.

In the conventional method for producing organosulfonyl chloride (hereinafter referred to as methylsulfonyl chloride or MSC), the by-product organosulfonic acid (hereinafter referred to as methanesulfonic acid or MSA) is 1000 copies (1oo.

ppm) and are present at very high levels and cannot be completely removed by normal purification processes.

US Pat. No. 1,626,004 discloses the preparation of methyl mercaptan and chlorine by direct reaction in 36% aqueous hydrochloric acid. Since HCI increases the steady-state concentration of impurities, the contamination of the MSCs removed from the reaction is still high due to the lack of extraction of impurities by clean HCI water. As taught in that patent, topping the water-containing product at high temperature (75° C.) assists in the hydrolysis of M2O and causes the impurity level of the product to remain high.

When preparing alkylsulfonyl chlorides having 1 to 4 carbon atoms in the alkyl group, the crude product is recovered as a bottom liquid phase containing coagulated water, MSA, and HCI water. Because MSA and water form tightly bound hydrates, and because acids and water have relatively high boiling points, it is possible to combine M8 and water even under vacuum without producing undesirable additional by-products. It is extremely difficult to vaporize from MSC. The purification procedure of the p004 patent does not overcome this problem.

No. 995,692 to U.S. Patent No. 62 to the above-mentioned patent
No. 04 discloses a similar MSC manufacturing method. The crude product is cooled and some separation of impurities is performed before phase separation and stripping of the MSC. Some product is also recovered from the contaminated aqueous HCI phase by extraction with benzene. However, the product is still α
Contains more than 5% impurities.

US Pat. No. 4,280,966 discloses a process for coproducing MBC with concentrated hydrochloric acid. As the crude product is produced, it is taken off the top of the column and some of the -JvI volatile components, such as HCj, are separated by the "cyclone" gas fraction 111 lea. This leaves some HCI as well as the less volatile water and MSA in the al Msc product. Then,
Inert sweep on the crude product under reduced pressure
A gas purification operation can be performed to purge the HCI. The product still contains undesirable amounts of impurities.

DESCRIPTION OF THE INVENTION Means for Solving Problems The present invention provides a solution to the gI of crude liquid organosulfonyl chloride product recovered from an organosulfonyl chloride production process or otherwise found in a similarly contaminated state.
the crude product for a period sufficient to first extract the diorganosulfonic acid with a clean aqueous hydrochloric acid solution having an acid concentration of at least about 18% based on the overlay of the solution. A scrubbing contact was made and cleaned (sCr
ubb@d) Separating the product from the hydrochloric acid solution and then stripping the washed product to form the by-product sulfonic acid from the organosulfonyl chloride at a temperature typically lower than that and at a humidity of about 500 Torr. under low vacuum)
During IJ tubing, the volatiles generated from the organosulfonyl chloride are blown away during stripping with an inert gas.

DESCRIPTION OF THE INVENTION The present invention provides a process, preferably continuous, for the comparative removal of organosulfonic acids and volatile impurities from crude liquid organosulfonyl chloride recovered from an organosulfonyl chloride production process or contaminated by other means. It's a method.

The organosulfonyl chloride treated in this method is an organosulfonyl chloride of the formula PaChCj, where R is an alkyl group having from 1 to 12 carbon atoms. Examples of these R groups are methyl, ethyl, propyl, butyl, isobutyl, pentyl, hexyl, octyl, dodecyl.

Preferred R groups are C1-C4 alkyl groups. Particularly preferred is methyl.

The scrubbing solution for the first treatment step of crude aM8C in the present method must itself be substantially pure or free of conventional MBC process contaminants. The effective concentration of the scrubbing hydrochloric acid aqueous solution is about 18 to about 36% MCI based on Fi bath solution overlay. The concentration is 50-3 to significantly reduce the rate of M2O hydrolysis by water.
A range of 6% is preferred. As used herein, the term "scrubbing" solution refers to a solution that, when intimately mixed with the crude MSC product, solubilizes undesirable by-products and leaves the insoluble main product free of undesirable contaminants. It means that it can be collected. As used herein, the term "scrubbing contact" refers to contacting the scrubbing solution with crude M
It is meant to homogeneously mix the SC product as a static solution in the column, or the scrubbing solution and the crude MSC in countercurrent or, less preferably, cocurrent flow.

The effective contact time of crude 1zMsc in the scrubbing solution ranges from 3 to about 60 minutes. Suitable contact time Fi
It is between 3 and 15 minutes.

The effective operating temperature of the scrubbing solution in the first step is in the range from the flow point of the hydrochloric acid solution to the point (for 36% HCj, the range is -17° to 110° C.). A preferred range is from about 08°C to about 50°C, and more preferably from about 10°C to about 25°C.

In bench or plant scale operation of the process, the scrubbing solution is used in the first unit or scrubber column. The scrubbing solution (a) removes MS and its hydrates from the crude MSC and (b) promotes the hydrolysis of the MSC by the presence of excess chloride ion to push the hydrolysis equilibrium toward sulfonyl chloride. Prevent (
C) the ionic strength of the aqueous solution reduces the solubility of MSC in the scrubbing medium by even making the slightly polar M2O more hydrophobic; and (d) the use of the scrubbing acid solution as feed to the reactor reduces the
The ultimate loss of SC can be prevented and the product suspended in the isthmus can be collected in a typical decantation step.

Since the by-product Mi9A binds up to three molecules of tightly bound water, the presence of M8A during stripping will push more loosely bound water away from the MSA. need to be used. Only under harsh conditions that can degrade MBC can the strongly bound water of hydration be separated from MSA. Removing the by-product MSA prior to stripping allows water to be removed at lower temperatures in the raised ball of yarn during the stripping operation.

Once MSA is removed, mild stripping conditions must be used to prevent further MSC hydrolysis. Stripping takes place in the second unit or stripping section of the process. As used herein, a "stripping" candy is defined as one or more candies capable of maintaining the cleaned NSCs at a vacuum pressure as low as about 50 Torr and a temperature of at least 100°C when under vacuum. and within the scope of the present invention) I
Refers to the operation of increasing the J-tsuping pressure and temperature.

The operating temperature of the vacuum stripper ranges from about 20° to about 70°C. A preferred temperature is about 40° to about 60°.

In plant operation of this process, the stripper section consists of two vessels in series. The first container averages about 7
Operating at 0° C. and an average pressure of about 230 Torr, nitrogen gas sweeps away volatiles. Most of the water in MBC is contained in this first
After removal in the container, the MSCs are passed into a second container. Since most of the water has been removed, the second container has a temperature of 85-95°C and a pressure of 160°C! Nitrogen is bubbled through the MSC to entrain some of the remaining volatiles with the nitrogen. This step delays the MSCs from being exposed to the morning temperature of the second container until almost all the water is removed. This avoids conditions that promote hydrolysis of MSC to MSA, a substance that binds water and makes removal more difficult.

The operating pressure can be any vacuum that effectively removes volatile impurities when using a vacuum source of limited efficiency.

Typical operating pressures for steam jets at 60 DEG C. range from about 201 Torr to about 350 Torr (consisting of the water vapor pressure of 149 Torr, residual volatiles, and air sweep). Normally, the operating vacuum pressure is about 100 to about 50
It is in the range of 0 torr.

During the stripping operation, an inert gas is passed through the volatiles generated from the MSC product as it is being stripped (allowing the volatiles to be swept away). The gas can be any inert vapor, but preferably dry air, nitrogen or helium are used. The inert gas is blown in a sufficient amount to remove volatile contaminant vapors that are stripped from the MSC product. Typically, at least about 15 volumes/minute of gas are used per unit volume of MSC in the slipper. In the stripper 'BdE, a sweep gas of between about 1 and 2 h/min per unit volume of MSC is used. The combined stripping and sweeping operations are carried out for a time sufficient to remove k by-products to provide the desired purity of the MSC product. Usually about 3 to about 60 minutes is sufficient.

Adding a sweep of inert gas over the solution being stripped helps to carry away any vapors of volatile contaminants. The inert gas sweep increases IJ collar efficiency and allows the use of lower temperatures as well as higher balls of yarn. A temperature reduction of 80° to 50° C. of the treated MBC reduces the hydrolysis rate constant of the MBC by a factor of, for example, at least 100 times.

The following examples illustrate the method of the invention.

Example 1 A glass (scrubber) column with a diameter of 2.51 and a length of 501 mc 56f [t%], hydrochloric acid (HCt), water t'A, methanesulfone a (M8A) 1.900
ppm (cL 19% by weight) and water 1,1ooppm (
Crude methanesulfonyl chloride (MSC) 10- containing α11 weight ff 1%) was added to a static bath at 25°C.
It was added dropwise over 0 minutes. MSC in concentrated H for 10 min at ambient temperature.
I left it in contact with C. The MSC is easily decanted from the scrubber tower, appears transparent, and has an α001% M
It contained 8A and α2% water. No hydrolysis of MSCs could be detected during the scrubbing process.

The above procedure was repeated except that the scrubbing solution was replaced with an aqueous HC solution having an acid concentration of 18% based on the weight of the solution. M
The SC is easily decanted from the scrubber tower, and the content of slightly male C (hazyLMsA) is lower than (LOO1%).
There weren't many. The amount of MSA in the cleaning core liquid is α1 at 25°C.
% hydrolysis had occurred.

The decanted product obtained from the concentrated (36%) HCl scrubbing solution is filtered through a rotating N membrane (th(n -fllm), 5-shot (
I put it in a stripper). 200 Torr vacuum on the MSC;
The stripping was carried out at 50°C. Clean, dry air was passed from the tube through the IJ collar at a rate of 41 J torr/min per liter of MSC in the stripper, and the thread pressure was increased to 350 torr. The thin film steamer rotated at a speed of 35 rpm.

MSC foil α001% recovered after 10 minutes of exposure time
of MSA and <α011% of water.

The above purification results are as follows:
After washing with I and then decanting, 30
rl) Rotational motion M rotating at m! shows a marked difference compared to the results seen for the M8C product stripped for 10 minutes in the absence of dry sweep gas at 250 Torr pressure and 80°C temperature in the 4 evaporation process. Under these conditions MSCs have (115% MSA and (105%)
It contained % water. Using higher temperatures to drive loosely bound water from the MSA caused the formation of MSA byproducts that were not removed during stripping.

Example 2 A large-scale operation purifying the product MSC for use in an M5C manufacturing plant consists of (1) a 1-foot diameter (α5 m ) and a 15-foot high (4.6 vQ) scrubbing vessel;
) Teflon-lined steel tower and (2)
Includes stripping section. When the washed MBC settles, the scrubber tower is heated to 2 feet (CL6m).
and a 1 inch (2,51) ceramic sa F
(approximately 9 feet wide) (2,7
m) and an intermediate filling section approximately 4 feet in height (
It consists of an upper area of 12 m ).

The stripping section consists of two steam-heated glass pots connected in series. The first stripper is a 114-inch (2q O(31)) high column with a bottom 50-inch (7M3) high section that is 8 inches (20cx) in diameter and a top 84-inch (2t3) high section.
cm) section is 6 inches (15 cm) in diameter. The bottom section houses a glass steam coil to heat the MBC to be stripped. This class)
The IJ tube has an MSC inlet on the 40% total level loading and an outlet on the opposite side at the bottom of the column. A 1 inch (2, s cm) horizontal tube is connected to the top of the IJ tube to remove volatiles from the top of the column and to provide a path for the sweep gas with volatiles. The second stripper is similar to the first stripper, but the top section is only 55 inches (140C11) high and the total tower height is 85 inches (216 cm). Since the volume of the second stripper is smaller than the first stripper, the MSC inlet of the second stripper is above the 50% total level, but the outlet is also at the bottom of the column. In addition, the second
The stripper has a gas inlet at the bottom to allow sweep gas to bubble through the MSC during the final stripping step. Sweep gas and volatiles from the second stripper are removed through a 1 inch (2, scm) horizontal pipe at the top and returned through the pipe to the top of the first stripper. The volatiles are blown away and the sweep gas and volatiles from both strippers are removed overhead.

During operation, the scrubber column was first completely filled with 515% concentrated clean hydrochloric acid. Crude MSC containing CL1-α2% water was placed on top of the column packing at a flow rate of approximately 5 gallons/min (
15) 47 minutes) and hydrochloric acid was continuously passed into the column from below the top of the packing at a flow rate of 15 gallons/hour (5,71/hour).
Then I pumped it through a rotameter. M at ambient temperature
A droplet of BC falls onto the packing and comes into homogeneous contact with the hydrochloric acid;
The MSC formed a layer at the bottom of the column with virtually all MSA removed. The hydrochloric acid passed upwards in contact with the descending MSC and exited the top of the column.

The wet breast MSC, free of MSA, was passed from the bottom of the scrubber column at a flow rate of 5 gallons/minute (191/minute) to the first stripper of the automatic pulp scrubber. In the first stripper, the temperature was maintained at about 70°C and the pressure averaged about 250 Torr. Under these conditions, over 90% of the water was boiled off and removed overhead with the aid of a nitrogen sweep gas.

The MSC was passed through a second stripper, which was brought to approximately the same pressure as the first stripper but at a much younger temperature of 90"C on average, to squeeze out virtually all of the water. In the second stripper, nitrogen was flushed out. jmcfH1(CL 02 B
5 m" (7 minutes) (unit volume of MSC in each IJ collar section - approximately 1 $ volume of gas per unit) was bubbled through the middle of the column.

2nd step) The MSC recovered from IJ tube contained less water than 150 parts per million.

Nee Dofu Hiroshi Ma Shipa 1\, ,
′

Claims (1)

Claims: 1. A method for purifying a crude liquid organosulfonyl chloride product recovered from an organosulfonyl chloride production process or otherwise similarly contaminated, comprising first adding a weight of solution to the crude product. At least about 18 on the basis of
scrubbing with a clean aqueous hydrochloric acid solution having an acid concentration of % for a sufficient time to extract the organosulfonic acids;
The washed product is separated from the hydrochloric acid solution and the washed product is then stripped at a temperature below about 70° C. and under a vacuum below about 500 Torr, while removing the volatiles resulting from the organosulfonyl chloride being stripped with an inert gas. 2. A method comprising allowing a minute to flow through and then recovering the purified organosulfonyl chloride product. 2. The method according to claim 1, wherein the organosulfonyl chloride is C_1-C_4 alkanesulfonyl chloride. 3. The method according to claim 1, wherein the hydrochloric acid solution has a concentration of 30% or more. 4. The method according to claim 1, wherein the temperature of the acid solution is . 5. The method of claim 1, wherein the residence time of the organosulfonyl chloride in the scrubbing solution is about 5 to about 15 minutes. 6. The method of claim 1, wherein the stripping temperature is about 40° to about 60°C. 7. The method of claim 1, wherein the total stripping pressure is less than 350 torr. 8. Air with a partial pressure of inert gas less than 350 torr;
The method according to claim 1, wherein nitrogen or helium is used. 9. The method according to claim 8, wherein the flow rate of the inert gas is 0.5 unit volume/minute or more per unit volume of organosulfonyl chloride. 10. First, the crude methanesulfonyl chloride product is dissolved with a clean aqueous solution of hydrochloric acid, based on the weight of the solution.
Scrubbing with an acid concentration of about 36% for about 3 to about 15 minutes,
The washed methanesulfonyl chloride was decanted from the hydrochloric acid solution, and the methanesulfonyl chloride
The stripping is carried out at a temperature of about 60° C. and under a total pressure of less than 350 torr, during which the volatiles arising from the stripped methanesulfonyl chloride are flowed at a rate of not less than 1.0 unit volume per minute of organosulfonyl chloride. A process for purifying a crude methanesulfonyl chloride product comprising blowing with an inert gas and achieving a partial pressure as low as 350 torr. 11. The method according to claim 10, wherein the temperature of the hydrochloric acid solution is about 10°C to about 25°C.