DE2755186A1 - CATALYTIC PROCESS FOR PRODUCING PERCHLOROMETHYL MERCAPTANE FROM CHLORINE AND SULFUR CARBON, AND PROCESS FOR STABILIZING CRUDE PERCHLOROMETHYL MERCAPTAN PRODUCED BY PROCESS CATALYZED WITH IODINE - Google Patents

Description

Our! Ir. 21 -o7 F / La

Stauffer Chemical Company Westport, Conn., V.3t.Λ.

Catalytic process for the production of perchloromethyl mercaptan from chlorine and carbon disulfide, as well as processes for stabilizing crude perchloromethyl mercaptan, the was produced by an iodine-catalyzed process,

The present invention relates to the use of carbonyl compounds, Phosphates and / or phosphites, phosphonates and / or phosphonites as additives to improve the Yield of perchloromethyl mercaptan.

Perchloromethyl mercaptan, Cl ^ CSCl, also under the name trichloromethanesulfinyl chloride known, is an important intermediate in the manufacture of fungicides, bactericides, Germicides, herbicides, soil disinfectants and pharmaceuticals.

Perchloromethyl mercaptan was first described by Rathke in Annalen, Vol. 167, page 195 (1873). That still used today Rathke's method uses an iodine catalyst. The reaction will be most effective at temperatures below etv / a ^ O C performed in accordance with the following equations:

CS ₂ + 3Cl ₂ VCCl ₃ SCl + SCl ₂ (1)

2CC1 SCl + S ₃ Cl ₂ (2) + 3Cl ₂ > CCl ₂₁ + S ₂ Cl ₂ (3)

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275518G

In addition to sulfur dichloride, sulfur chloride (also as Sulfur monochloride known) and carbon tetrachloride can prove to be further undesirable in the implementation By-products form thiophosgene and other compounds. Although more volatile by-products such as carbon tetrachloride and sulfur dichloride, which can be removed from the reaction mixture by distillation, is extraordinary difficult to separate perchloromethyl mercaptan from sulfur chloride in this process. This is due to the fact that the boiling points of perchloromethyl mercaptan and sulfur chloride are very close to one another.

Various methods have been proposed to improve the Rathke basic method. For example is a method of manufacture in U.S. Patent 3,5M,625 of perchloromethyl mercaptan by chlorination of carbon disulfide in the presence of a solution of an inorganic Acid such as hydrochloric acid. From US Pat. No. 3,673,26 there is a continuous process for production known from perchloromethyl mercaptan, in the case of carbon disulfide with chlorine via activated carbon or in intimate contact is implemented with this at temperatures of about -5 to +100 C. U.S. Patent 3,808,270 is a continuous process for the production of perchloromethyl mercaptan disclosed, in which carbon disulfide and chlorine in one Reaction zone, which is filled with granular activated carbon, which is completely immersed in the liquid reaction mixture, implemented / while temperatures range from about HO to about 135 ° C. In U.S. Patent 3,878 2 ^ 3 is a homogeneous catalyst system discloses which a lead salt; a carboxylic acid soluble in carbon disulfide.

Regardless of the effectiveness of the aforementioned known processes for the production of perchloromethyl mercaptan (im the following abbreviated a.3 "PMM" r.), deal with this

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not to prevent the tendency of PMMj with chlorine or sulfur dichloride with the formation of carbon tetrachloride, Sulfur and sulfur monochloride react. Mixtures of carbon disulfide and sulfur dichloride also react and perchloromethyl mercaptan in a similar manner. It is believed, that the reactions in which carbon tetrachloride is formed are caused by trace amounts of metals, e.g. Iron and tin as accelerated by bronze in the reaction mixture will.

Small amounts of iron are typically present in the commercially available carbon disulfide and chlorine which are used as reagents for PWA , in concentrations on the order of parts per million. The chlorine can be treated by passing it through a glass wool filter which will remove most of the iron. However, the content of iron in concentrations as low as one part per million can be detrimental and cause substantial reductions in the yield of perchloromethyl mercaptan. Accordingly, it has been an aim of the industry to develop means which will eliminate the effects of metallic impurities in the reagents and / or the catalyst so that the formation of carbon tetrachloride, sulfur monochloride and other undesirable by-products is suppressed.

Another problem with the production of perchloromethyl mercaptan represents the decomposition of sulfur dichloride to sulfur monochloride and chlorine according to the following equation:

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This reaction is undesirable due to the fact that the boiling points of perchloromethyl mercaptan and sulfur chloride are so close together that it is impractical to separate them by distillation. Consequently It was also an aim of the industry to develop means of stabilizing sulfur dichloride, thereby reducing its formation to prevent sulfur chloride and chlorine.

Another task is the stabilization of crude perchloromethyl mercaptan, which was made by an iodine catalyzed process.

In the production of perchloromethyl mercaptan by the process in which iodine is used as a catalyst, must the crude perchloromethyl mercaptan is separated from the reaction by-products and dsm iodine as a catalyst by distillation will. Since the process for the production of perchloromethyl mercaptan in the presence of iodine as a catalyst is discontinuous some time passes before the crude perchloromethyl mercaptan can be purified by distillation. A The problem which arises is that the crude perchloromethyl mercaptan and its by-products have the following Respond wisely:

2SCl ₂

S ₂ Ci ₂ ♦ Ci ₂ (5) CCl ₄ ♦ S ₂ Ci ₂ (6) 2CCl ₄ ♦ S ₂ Ci ₂ (7)

^τ 2
SCl ₂ + Cl ₃ CSCl -

Cl ₂ + 2Cl ₃ CSCl -

These conversions are undesirable because SpCIp is formed which is a by-product that is difficult to separate from perchloromethyl mercaptan by distillation can, which is why the purity of the end product is reduced,

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Also kar.r. the v;:; CIp that forms during reaction (5) rides Perchloromethyl mercaptan as shown in reaction (7), react, whereby the yield of perchloromethyl mercaptan is further reduced. The implementations (6) and (7) can also convert perchloromethyl mercaptan into carbon tetrachloride, which further reduces the perchloromethyl mercaptan yield he follows.

US Pat. No. 3,379,253 discloses stabilizers for production of sulfur dichloride, such as trialkyl phosphites, phosphorus pentachloride or trialkyl phosphates, disclosed, which are to be used in the distillation of sulfur dichloride in order to decompose sulfur dichloride into sulfur monochloride and inhibit chlorine.

increase

According to the invention, the yield / of perchloromethyl mercaptan and / or the suppression of undesirable by-products is achieved by using one of the following Groups of additives added to the reaction system:

I. Carbony! Compounds;
II. Phosphates and / or phosphites; as well as III. Phosphonates and / or phosphonites.

The Group I carbony compounds which have been found to be most effective are bifunctional; they have the following general formulas:

RC (-CX ₅ - * - CR (A)

Il <- ⁿ Il

0 0

RC- fr- CX ₀ - * - CH-R (B)

ι * - η,

0 OR ¹

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wherein R is independently a hydrocarbyl, alkoxy, or substituted hydrocarbyl group; R ^{1 is} independently an alkyl group or a hydrogen atom; X is independently a hydrogen or halogen atom; and η is an integer from 0 to 3.

Typical examples of hydrocarbon groups are alkyl, Cycloalkyl, aralkyl, alkaryl and aryl groups, where the alkyl groups are 1 to et; * a 20, preferably 1 to about 10, Include carbon atoms. The alkyl groups can be straight or branched chain or cyclic.

Typical substituted alkyl and substituted aryl groups are alkyl or aryl groups that have at least one substituent vrie a halogen atom, a cyano, carboxyl, carboxylate, amido, amino, nitro, hydroxy or alkoxy group bonded where the substituents are the production of perchloromethyl mercaptan may not adversely affect. The preferred substituents are halogen, especially chlorine.

A typical aryl group is the phenyl group. Typical alkaryl groups are cresyl and xylyl groups, while a typical aralkyl group is the bensyl group. Typical examples of preferred bifunctional carbonyl compounds and derivatives thereof, which are particularly wirksan for increasing the yield of perchloromethyl, the Alkyldione with etv / a ^ to about 10 carbon atoms, such as butane Dione, pentanediones, Hexandione, Heptandione, Octandione, Nonandione, Decandione , their mixtures and their isomers.

There have also been improved yields of perchloromethyl mercaptan by adding small amounts of the phosphates and / or phosphites of the above-mentioned group II to the Reactior.s:; y3t «r. achieve * ...

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Those group II phosphates and phosphites which Proven to be most effective, possess the following general Formulas

P = O (C)

respectively.

(D)

in which R, R ¹ and R "independently of one another denote hydrogen atoms or hydrocarbon or substituted hydrocarbon groups, but not all of the substituents R, R 'and R" can be hydrogen atoms at the same time.

Typical examples of hydrocarbon groups are alkyl, aralkyl, alkaryl and aryl groups, the alkyl groups having 1 to about 20, preferably 1 to about 10, carbon atoms. The alkyl groups can be straight, branched or cyclic.

Examples of substituted alkyl and substituted aryl groups are alkyl and aryl groups to which at least 1 substituent such as a halogen atom, the cyano, carboxyl, carboxylate, amido, amino, nitro, hydroxy or alkoxy group is attached, with the proviso that the substituents do not adversely affect the production of perchloromethyl mercaptan. The preferred substituents are halogen atoms, especially chlorine.

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A typical aryl group is the phenyl group. Alkaryl groups can be the cresyl or xylyl group. An example for the aralkyl group is the benzyl group.

Typical examples of the preferred phosphates and / or phosphites, which are used to increase the yield of perchloromethyl mercaptan Proven to be particularly effective are those having alkyl and substituted alkyl groups of from about 4 to about 10 carbon atoms.

Improved yields of perchloromethyl mercaptan were also achieved by adding small amounts of the phosphonates and / or phosphonites of the above-mentioned Group III to the reaction system.

The phosphonates and phosphonites that have been found to be most effective have the following general formulas:

R ¹¹ O

(E)

RR ¹¹ OP-OR ¹ (F)

In formula (E), R is independently hydrogen or chlorine, hydrocarbon, or substituted hydrocarbon; R ¹ and R ″ are independently R, but not a chlorine atom, although not all of the substituents R, R ¹ and R ″ can be hydrogen atoms at the same time. In formula (F), R is independently a hydrogen or chlorine atom or a hydrocarbon or substituted hydrocarbon radical, while R ¹ and R "

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- lit -

are independently R, but not chlorine or Hydrogen atom.

Typical examples of hydrocarbon radicals are alkyl, cycloalkyl, aralkyl, alkaryl and aryl radicals, the alkyl radicals having 1 to about 20, preferably 1 to about 10, carbon atoms. The alkyl groups can be straight, branched or cyclic.

Typical examples of substituted alkyl and substituted aryl groups are alkyl and aryl groups to which at least one substituent such as a halogen atom, the cyano, carboxyl, carboxylate, amido, amino, nitro, hydroxy or alkoxy group is attached , with the proviso that the substituents do not adversely affect the production of perchloromethyl mercaptan. The preferred substituents are halogen atoms, especially a chlorine atom.

Typical phosphonates and / or phosphonites, which have been found to be particularly effective for increasing the perchloromethyl mercaptan yield, have alkyl and substituted alkyl groups with about Ί to about 10 carbon atoms .

The addition of the compounds of groups I, II and III in the manufacture of perchloromethyl at most effectively achieved by bringing the compound in situ with carbon disulfide and then contacting the catalyst and chlorine / admits.

The phosphate and / or phosphite compounds of group II and the phosphonates and / or phosphonites of group III must be used with a catalyst which is inert to these compounds. For example , the Group II or III compounds will not work with iodine as a catalyst.

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- 13 -

In the case of the compounds of group I, the reaction temperatures which are required for the batchwise production of PMM are generally lower than the temperatures, many of which can be maintained in a continuous process. For example, the temperature for a batch process are generally from about 10 to about ¹ IO ⁰ C, when a carbon or iodine catalyst is used. At about above ¹ IO ⁰ C in a batch process, the PMM would tend to decompose in CCl ^ and S "C1. ₂ The catalyzed by iodine system is preferably carried out below ¹ IO ⁰ C either in a continuous or discontinuous manner. The catalyzed system with carbon can be performed at temperatures above 40 ⁰ C in a continuous manner, if this is done according to the US-PS 3 8O8 270th

It has been found that with compounds of Groups II and III, activated carbon is the most effective catalyst. This catalyst is in with the reaction mixture of carbon disulfide and chlorine for an extended period of time Brought into contact while maintaining the reaction temperature at about 0 to about 135 ° C. Even when using the connections according to groups II and III, the reaction temperatures required for the production of PMM according to a batch process are required, usually lower than the temperatures used in can be sustained in a continuous process. For example, the temperatures are generally about 10 to about 10 ° C in a batch process when a carbon catalyst is used will.

The compounds of groups I, II or III are usually added in amounts which are about 0.01 to about 10, preferably about 0.1 to about 5% by weight, based on the

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Carbon disulfide loading. It can Larger kengen can also be used, but there is no benefit from this.

It was also found that the breakdown of crude perchloromethyl mercaptan, which was produced by an iodine-catalyzed process can be effectively prevented, by adding small amounts of phosphorus derivatives to the crude perchloromethyl nercaptan.

The phosphorus derivatives, which were found to be the most effective, are phosphonates of the general formula

R ¹¹ O

R'O

wherein R independently denotes a hydrogen atom, a hydrocarbon or a substituted hydrocarbon group, and R ¹ and R "independently of one another have the meaning of R and can additionally denote a chlorine atom, but not all of the substituents R, R 'and R" simultaneously Can be hydrogen atoms.

Typical examples of hydrocarbon groups are alkyl, Cycloalkyl, aralkyl, alkaryl and aryl groups, where the alkyl groups are 1 to about 20, preferably 1 to about 10, Have carbon atoms. The alkyl groups can be straight, branched or cyclic.

Typical examples of substituted alkyl and substituted aryl groups are alkyl or aryl groups to which at least 1 substituent such as a halogen atom, the cyano, carboxyl, carbcxylate, amido, amino, nitro, hydroxy or alkoxy group is bound, with the proviso that the substituents

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the production of perchloromethyl mercaptan is not disadvantageous influence. The preferred substituents are halogen atoms, especially a chlorine atom.

A typical aryl group is the phenyl group. The alkaryl groups can be, for example, cresyl or xylyl groups. The alkaryl group can be a benzyl group.

Typical examples of the preferred phosphonates, which are used to stabilize the crude perchloromethyl mercaptan Those having alkyl and substituted alkyl groups containing from about 1 to about 10 carbon atoms have proven particularly effective exhibit.

The addition of the phosphonate stabilizers is most effectively accomplished by adding them to the crude perchloromethyl mercaptan added immediately after completion of the discontinuous reaction catalyzed by iodine.

The phosphonate stabilizers are usually added in amounts which are about 0.5 to about 5> preferably about 1 to about 3% by weight, based on the crude perchloromethyl mercaptan product, be. Although larger amounts can be used, there is no benefit from this. It has been found that, as a rule, the use of the phosphonate stabilizers is limited to that described above Way, the formation of the undesired by-products resulting from reactions (Ό, (5) and (6)) is considerably reduced, thereby improving the purity and yield of the perchloromethyl mercaptan.

The following examples serve to explain the invention in more detail; herein, unless otherwise specified, all Parts and percentages are based on weight.

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Examples 1 to 11 illustrate the process according to the invention using the bifunctional carbonyl compounds of group I.

Examples 1-9

In a 250 ml-.mit coat LABEL FOR glass flask, which was equipped with an inlet tube for chlorine, a dry ice condenser and a mechanical stirrer was added 76 g (1 mol) of carbon disulfide and 0.3 g of iodine, 0.5 g of 2,3- Hexan dione brought into contact. This mixture was then reacted with 182 g (2.6 mole) of chlorine in contact, which bubbled for ¹ 1/2 hours I was left. During the introduction of chlorine, the reaction temperature was maintained by external cooling to about 20 to about 2 ¹ J ⁰ C. The reaction mixture was then distilled under vacuum at a temperature of 70 to 100 ° C. at 200 torr. This gave I ¹ II, ¹ * g (0.76 mol) of perchloromethyl mercaptan . This represents a 89% yield based on the converted chlorine ·. The above procedure was repeated in sequence with the exception that a different bifunctional carbonyl additive was added . The results are shown below:

E.g. additive

Amount (g) PMM Yield (Jt)

Ethylacetoacetate CH-C-CH ₀ C-CH ₀ CH,

0 0

Diethyl malonate CH _x CH ₀ OCCH ₀ COCH-CH,

J <- It <-ll <- J

0 0

Dimethyl oxalate CH _x OC-COCH,

J II If J

0 0

0.5 0.5 0.5

82

86

83

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E.g.

Additive

Acetylacetaldehyde dimethyl acetal

CH, C-CH ^ -CHOCH,

Amount (g) PMM yield {%)

OCH

6 acetylacetone CH, C-CH ₀ -C-CH-,

-> ll ^ Il J

0 0

7 acetylacetone

8 benzoin

OH

0.5

0.5

ο, ι ^Ί

0.5

85

93 85

80

using 0.2 g of iodine Example 10

In a 250 ml glass flask with a jacket, which was provided with an inlet tube for chlorine, a dry ice cooler and a mechanical stirrer, 76 g (1 mol) of carbon disulfide, 28 g of charcoal (commercial product CXAL from Union Carbide, a coconut charcoal) and 0.5 g of acetylacetone brought. Water thermostated to 25 ° C. was continuously circulated through the flask jacket. The solution was stirred and 182.0 g (2.6 moles) of chlorine was bubbled through the reaction mixture over 4 hours. A total of 198 5 liquids were separated ^{from the charcoal by vacuum distillation at 70 to 100 °} C., the vacuum being in the range from 50 to 60 Torr. A total of 119 g were obtained as distillate, Tk g as condensate in the dry ice trap and an additional 5 g when the charcoal was washed out with chloroform. According to an analysis of the various liquid fractions, the yield was

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of PMM 122 g, which means a yield of 78 %, based on the chlorine converted. The yield of the by-product was 2 % of theory.

Example 11

The procedure of Example 10 was repeated, but without the additive. After completion of the reaction, 219 U of liquid were obtained, which comprised 128 g of distillate, 85 g of condensate in the dry ice cold trap and 5.7 g, which were obtained by washing out the charcoal with chloroform. The analysis of the various farctions by gas chromatography showed a yield of 128.5 g PMM, ie 69 %, based on converted chlorine, and 19 % CCl _1,.

Example 12 (continuous implementation)

This and Examples 13 to 15 illustrate the process according to the invention using the phosphates and phosphites according to group II.

A glass tube with an inside diameter of 3.8 cm was filled to a height of 76 cm with the granular activated carbon used in Example 10 with a grain size corresponding to a mesh size of 2.38 to 1.68 mm. The glass tube was provided at its top with an inlet line for the carbon disulfide charge and at the bottom with an inlet line for the chlorine charge and also at the bottom with a drain for collecting the crude product. A reflux condenser was attached to the steam outlet of the tube in order to avoid the loss of carbon disulfide. The carbon disulfide was overturned. Glass vessel in a long enough to cover the catalyst bed, Pcdar.n, CIp was fed to the reaction vessel until about 90% of the C5 had set

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(determined by gas-liquid chromatography). Cl_ and CSp were then fed in at the same time in a ratio of 3 moles Cl ₂ to 1 mole CS ₂ . The PMM tube was withdrawn from the bottom of the reaction vessel at a rate such that the liquid level in the vessel was maintained at the top of the catalyst bed. The maximum temperature in the reaction ^{vessel was kept at 110 0} C or less by increasing the CSp feed rate to about 0.16 g CS _? / g catalyst per hour was limited.

This experiment was then exactly repeated, but with the exception that the CS ₂ 3 wt. (based on CS ₂ ) tributyl phosphate (TBF) were added; the following results were obtained:

Without With 3? TBF TBF 98.0 98.2 78.8 96, Jl 21.2 3.6 11.0 2.4 77.2 9 ^, 7 20.8 3.5

CS ₂ conversion (?)
Selectivity with regard to PMM (?)
Selectivity with regard to CCl ^ (?)
S ₂ Cl ₂ in the distilled product (?) PMM yield, based on CS ₂ (?)
CCl ^ yield, based on CS ₂ (?)

Examples 13 - IS

Into a 200 ml jacketed glass flask equipped with a chlorine inlet tube, a dry ice condenser and a mechanical stirrer were placed 76 g (1 mole) of carbon disulfide, 30 g of the activated carbon used in Example 10 and 0.38 g of tributoxyethyl phosphene. Water heated to 35 ° C. was continuously circulated through the jacket. The solution was f.erührt, and there were relassen beads within ^l \ hours 182.9 g of chlorine by-si. 3 After separation from the charcoal

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a total of 2 ^ 7 g of liquid residue was removed from the flask won. This material was analyzed by gas-liquid chromatography (hereinafter referred to as "GFC" for short) analyzed. The results are in the table below contain. The procedure described above was repeated, but using different additives became; these results are also included in the following compilation:

E.g. Additive PMM yield (2) ¹ CCl ₁₁ (JS)

2 tributoxyethyl phosphate 95 5

Tris (β-chloroethyl) phosphate 99.3 0.7 (ClCH ₂ CH ₂ O) ₃ P = O

acid dibutyl phosphate 99.8 0.2

All yields are based on converted Cl ₂ ; the analyzes were carried out by GFC

The activated carbon was washed with HCl and then

neutralized.
Example l6 (continuous implementation)

This example and examples 17 to 21 explain the process according to the invention using phosphonates and phosphonites according to group III.

A glass tube with an inner diameter of 3.8 cm was filled with the granular activated carbon used in Example 10 clear dimensions:; width from 2.38 to 1.68 mm bir. at a height of 7ß cm f-o f- "i LLn. Dar, Reakt Lonngefäß was on top with a K inlaßLe itu.'i:; "i: ·: 1L ·; C ':';., -Π-.τ, οΗ iclrung and on ground with a

8 {) μ Γ:> 7 / η c β 7

Inlet line for the Clp feed and also provided at the bottom with an outlet line for collecting the raw product. A reflux condenser was placed on the steam outlet of the tube to avoid _{loss of CS 2.} C3 ~ was added to the reaction vessel in such an amount that the catalyst bed was just covered. Sodam, CIp was introduced into the reaction vessel until about 90? of the CS ₂ had implemented, which was determined by GFC. The reaction vessel was then charged simultaneously with Cl ₂ and CS ₂ in a ratio of 3 moles of CIp per mole of CS ~. Crude PMiI was withdrawn from the bottom of the vessel at a rate such that the liquid level in the vessel was maintained on top of the catalyst bed. The maximum temperature in the reaction vessel was maintained at 110 ° C. or less by limiting the feed rate of the CS ₂ to about 0.16 g CS ₂ / g catalyst per hour. The process described above was then repeated, with the exception that dimethylmethylphosphonate (DMMP) was added to the CSp charge in a concentration of 0.5% by weight, based on CS ₂ . The results are summarized below:

no additive 0.5% DMMP 98.0 98.8 78, B. 91.8 21.2 5.2 11.0 1.9 77.2 93.7 20.6 5.1

CSρ conversion (?)
Selectivity with regard to PMM (?)
Selectivity with regard to CCl ₁₁ (?)
S ₂ CIp in the distilled product
PPM yield, based on CS ₂ (?)
CCl ^ yield, based on CS ₂ (?)

Example 17 - 21 (discontinuous conversion)

In a 250 nl glass flask with a jacket, which is fitted with a Chlorine inlet tube, dry ice condenser and mechanical stirrer

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- 2k -

was provided, 76 g (1 mol) of carbon disulfide, 30 g of the activated carbon used in Example 10 and 0.28 g of dimethyl

brought ethylphosphonoacetate. By the piston skirt continuously thermo-oriented at 35 ° C was V / ater conducted in circulation The solution was stirred, and 182.9 g of chlorine were to within ¹ hours J bubbled. Of activated charcoal was gevionnen a total of 2 ^ 7 g of liquid residue, after removal from the flask. This r. Material was analyzed by GPC. The results are summarized below.

The process was repeated again one after the other using various additives and without an additive, the results also being obtained in the following compilation.

E.g. additive PMM yield (3Π CCl ₁ ^ (?)

2 dimethylethylphosphono

acetate 85 1

(CH ^ O) ₀ PCH ₀ COOC ₀ H ₁ -0

3 dimethyl methyl phosphonate 100 0 (CH ₃ O) _{2 PCH 3}

¹ J tetra- (ß-chloroethyl) -ethylene-

to _w phosphonate 99.8 0.2

/ TClCH ₂ CH ₂ O) ₂ PCH ₂ Z ₂
Ö

5 tetraethylmethylene bis

phosphonate 99.8 0.2

/ Tch _t ch _o 0) _o p7 "ch _o

- 3 2 2n d 2 0

6 - without - 77 21

All yields are based on urtf.eeetzzes Cl "; the analysis was carried out by Gr'C.

The activated carbon was washed with HCl and then neutral

_ TC "

Example 22

This example illustrates the stabilization of crude perchloromethyl mercaptan, which was made by an iodine catalyzed process.

As described in Rathke, supra, crude perchloromethyl mercaptan became produced in a discontinuous reactor with iodine as a catalyst. After completing the implementation 5 samples of the crude perchloromethyl mercaptan, each weighing approximately 3/4 g, were withdrawn from the reactor. One Sample labeled "Control" was immediately added with about 2 drops (approximately 0.05 g) of dimethyl methyl phosphonate (DMMP) and the sample was then analyzed by GFC. It turned out because of the Fact as necessary to stabilize the control before analysis by GFC that the samples of crude perchloromethyl mercaptan can react according to equations 4, 5 and 6 above, if they are exposed to the elevated temperatures in are exposed to the gas chromatograph, which leads to inaccurate analysis results. Bringing the In contrast, the control sample with the stabilizing agent led to a precise analysis of the sample withdrawn from the reactor raw PMM.

The remaining samples were treated as follows:

Sample 2 was immediately contacted with DMMP. This sample was ^l i hour at room temperature, allowed to stand and then analyzed by GFC.

Sample 3 was left to stand for 4 hours at room temperature, then brought into contact with DMMP, and then analyzed by GFC.

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Sample 4 was immediately brought into contact with DMMP and then left to stand for 2 hours at room temperature and 2 hours at 0 ° C., after which it was analyzed by GPC.

Sample 5 was left to stand for 2 hours at room temperature and 2 hours at 0 ^° C., then brought into contact with DMMP and then analyzed by GFC.

The results are summarized below:

Samples of raw PMM

component j.
(Control) 2 3 3 4th 5 Ci ₂ 0.10 0.71 0.16 0.53 0.07 cs ₂ 7.07 7.09 5.49 6.85 5.30 SCl ₂ 41.65 40.73 37.20 41.45 40.21 CCl ₁₄ 5.67 5.78 8.27 5.71 8.06 S, -jClp 1.32 1.15 2.75 1.03 1.79 Cl ₃ CSCl 43.91 44.24 45.92 44.13 44.57 All in all 99.72 99.70 99.79 99.75 100.00 component 1 2
(Control) 4th 5

C3 p-conversion

C: l "conversion,

based on PMM

CS ρ conversion,

based on CCIj. 10.1

Selectivity with regard to
PMM

Selectivity with regard to

relationship
PMM / S "C1"

74.6 74.7 80.6 75.3 80.7

64.5 64.5 66.2 65.1 66.2

10, I. 10.2 14.4 10.2 m , 5 86.5 86.3 »2, 1 a 6.5 82 , 0 13.5 13.7 17.9 13.5 18th , 0 33.3 33.5 16.7 42.8 2H , 9

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From the previous fourths it appears that the untreated samples, ie those which remained unatabilized for a number of hours prior to their analysis, showed a substantial increase in the amounts of S ^ Cl- and CCl ₁ . about the amounts obtained in the control and samples 2 and ^, which were immediately stabilized with DHMP.

For: Stauffer Chemical Company Westport, λ Conri. , V.St.A.

η ι k

Di ^ H.i. Wolff Lawyer

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Claims (1)

if ·. ·. IViHFF a BiSIl OS. Ii9 * OT7 C- ■ '' '■. χ- r a * ■ :: o rifi. \: <RU'vT am main so ^ Patent claims : 1. Catalytic process for the production of perchloromethyl mercaptan of chlorine and carbon disulfide, characterized in that the reactants with (A) a bifunctional carbonyl compound, (B) a phosphate, phosphite or mixture thereof or (C) a phosphonate, phosphonite, or a mixture thereof brings into contact in an amount which suppresses the formation of carbon tetrachloride and sulfur monochloride. 2. The method according to claim 1, characterized in that there is a carbonyl compound of the general formula RC (CX _O 4- CR ti c η υ 0 0 or R-C tCX -) - CH-R 0 OR ¹ is used in which R is independently a hydrocarbon radical, an alkoxy or a substituted hydrocarbon radical; R ¹ independently represents an alkyl radical or a hydrogen atom; X is independently a hydrogen or halogen atom; and η is an integer from 0 to 3. 3. The method according to claim 2, characterized in that an alkyl dione having about ¹ l to about 10 carbon atoms is used as the carbonyl compound. 809827/0667 owaWAL INSPBCTBD M. Method ^ er.ij claim I ₁ characterized in that the carbonyl compounds, phosphates and / or phosphites or phosphonates and / or phosphonites in one
Amount of from about 0.01 to about 10 % by weight based on the carbon disulfide feed used. 5. The method according to claim 4, characterized in that the compounds in an amount of about 0.1 to
about 5% by weight based on the carbon disulfide feed used. 6. The method according to claim 2, characterized in that iodine is used as the catalyst. 7. The method according to claim 1, characterized in that activated carbon is used as the catalyst. 8. The method according to claim 2, characterized in that a lead salt is used as a catalyst . 9. The method according to claim 1, characterized in that there is a phosphate of the general formula R ¹ OP = O is used, wherein R, R 'and R "are independent of one another
V. 'hydrogen atoms' mean hydrocarbon or substituted hydrocarbon radicals, but R, R' and R "together are not hydrogen atoms at the same time
can. 809827/0687 10. The method ger.äß claim 1, characterized in that one is a phosphite of the general formula is used in which R, R ¹ and R "independently of one another denote hydrogen atoms, hydrocarbon or substituted hydrocarbon radicals, but R, R 'and R" cannot be hydrogen atoms together at the same time. 11. The method according to claim 1, characterized in that one uses phosphates and / or phosphites and phosphonates and / or phosphonites, which C, - to about C _1Q - Are alkyl derivatives. 12. The method according to claim 1, characterized in that a phosphonate of the general formula R ¹¹ O R'O used, wherein R is independently a hydrogen atom, a hydrocarbon or substituted hydrocarbon and
rest or a chlorine atom, / R 'and R "are independent of one another have the same meaning as R £ but do not mean chlorine, however, R, R 'and R "cannot together be hydrogen atoms at the same time. 13- The method according to claim 1, characterized in that one is a phosphonite of the general formula B09827 / 0B67 R.
R ¹¹ OP-OR ' is used, wherein R is independently a hydrogen or chlorine atom or a hydrocarbon or substituted Hydrocarbon radical means, and R 'and R "independently of one another the meaning of R, but with the exception of Chlorine or hydrogen. lh. Process for stabilizing crude perchloromethyl mercaptan which has been produced by an iodine-catalyzed process, characterized in that an effective amount of a phosphorus derivative is used as the stabilizer. 15. The method according to claim lh, characterized in that a phosphonate of the general formula is used as the phosphorus derivative R ¹¹ O 1. ¹ O is used, wherein R is independently a hydrogen atom or denotes a hydrocarbon or substituted hydrocarbon radical, and R 'and R "are independent of one another have the meaning of R or represent chlorine atoms, but where R, R 'and R "are not taken together at the same time Hydrogen atoms can no. 16. The method according to claim 15, characterized in that nan uses a phosphonate, which is alkyl-substituted is. R09P? 7 / nF67 ^copv 17. The method according to claim 16, characterized in that one uses dimethyl methyl phosphonate. 18. The method according to claim I ¹ J, characterized in that the stabilizer is used in an amount of about 0.5 to about 5% by weight, based on the perchloromethyl mercaptan produced. 19. The method according to claim 18, characterized in that the stabilizer in an amount of about 1 to about 3% by weight, based on the perchloromethyl mercaptan produced. 809827/0667 _CQ £ Y