KR800001174B1 - Eradication of bis-chloromethyl ether and 1,1,1,2-tetrachloroethane from chloroacethyl chloride - Google Patents

Abstract

Pure chloroacetylchloride(I) was prepd. by catalytic removing of bischloromethyl ester(II) and 1,1,1,2-tetrachloroethane(III) at 50-140≰C, 15-120 min in the presence of F or Al cation catalyst such as FeCl3, Fe2Cl6, AlCl3, Al2Cl6, when the mixt. of 100 g I, 100 ppm II and 0.81% III was continuously refluxed at 105≰C with 1,4g anhydrous FeCl3, the eridication amount of II and III after 90 min was < 0.5(ppm)2 and < 0.05(wt.%)3, resp.

Description

[Name of invention]

Method to release bis-chloro methyl ether and 1,1,1,2-tetrachloro ethane from chloroacetyl chloride

Detailed description of the invention

The present invention relates to a method for releasing impurities from chloroacetyl chloride, chloroacetylchloroide mixed with various impurities and chloroacetyl chloride.

US Pat. No. 3,674,664 to Larsen et al. Describes a process for the photochemical oxidation of vinylidene chloride to produce chloroacetyl chloride (CAC). Although this is an excellent method from an industrial point of view, a small amount (100-250 ppm) of bis-chloro methyl ether (CME), known as carcinogen as impurity, and 1,1,1, There is a bond in which 2-tetrachloro ethane (TCE) is also a byproduct. Since CAC is used in the intermediate manufacturing of various pesticides and drugs, it is desirable to release most of CME and TCE from CAC whenever possible. Furthermore, the CAC, which is entertained by CME and TCE, is also expensive because the CME and TCE accumulate and block the CAC circuit. In addition, waste is produced.

Efficient release of CME and TCE from CAC is not achieved by conventional chemical and physical separation methods. CAC and CME have similar chemical functionalities, and CAC, TCE and CME have similar physical properties, and thus, conventional separation methods, such as sulphate blackening, fractional distillation, or a combination method, are invalid.

In U.S. Patent No. 4,054,602 dated Oct. 18, 1977, Dingra was prepared from a mixture containing hydrochloric acid and CAC and CME at a temperature of 30 ° C. to 160 ° C. in the presence of a catalyst of Lewis acid or strong amphoteric acid such as aluminum chloride or fuming sulfuric acid. The method of contacting describes the removal of CME from the CAC. However, in the method proposed by Dinggra, the use of hydrochloric acid is not important, and therefore, the present invention and the Dinggra invention may be different from each other. The presence of hydrochloric acid under certain conditions, especially at reflux temperature, is rather undesirable in the present invention.

Crystals resulting from conventional methods are actually overcome by the present invention, which is characterized in that the present invention is characterized in that, in a mixture of chloroacetyl chloride, bis-chloromethyl ether and 1,1,1,2-tetrachloroethane, 1,1,1,2-tetrachloroethanol release elimination is a method of contacting the catalyst of the iron and aluminum cation with the mixture at 50-140 ℃, and then lasts for 15-12 minutes.

CME and TCE have no adverse effects on CAC and are released below the detection level. The term "below the detection level" means here a release condition of less than 0.5 ppm with CME and less than 0.5% by weight (relative to the weight of the CAC) of TCE.

“Release” and similar terms herein refer to the conversion of CME and TCE to other compounds that are readily removed from CAC by conventional methods such as distillation (ie chloromethylchloro acetate and trichloroethylene). As a result, CAC free of CME and TCE can be used to convert impurities and other methods of flash distillation or removal of residual catalyst. During flash distillation, the CAC can be recovered with a purity of 98.5% or more and the catalyst residue is recycled.

The cations of iron and aluminum used herein can be generated and used from any other suitable source. In practice these cations are produced in chloride salts such as FeCl ₃ , Fe ₂ Cl ₆ , AlCl ₃ , Al ₂ Cl ₆ hydrates and anhydrides. However, other suitable sources include iron and aluminum fluorides, bromides, iodides, sulfites, acetates, tosylates, oxalates, nitrates, benzoates, phosphates, iron and aluminum oxides, and iron and aluminum deposits. have. Iron cations are superior to aluminum cations. Iron deposits, iron oxides, and iron chlorides are excellent sources of iron cations. The latter is good because other sources of anions (bromide, acetate, etc.) can be exchanged with chlorides of the CAC, thus producing new impurities and losing the CAC.

Iron chloride is most preferred. The iron and aluminum cations may be used alone (preferably) or mixed with each other.

These cations are used in catalytic amounts. For example, when iron chloride is the catalyst, it is used as a small amount of catalyst at least about 0.5, preferably 0.25% by weight (relative to CAC). Considering practical aspects such as catalyst recovery, economics and benefits, only the maximum amount of catalyst can be used.

In the case of FeCl ₃ about 2, preferably about 0.75% by weight is the maximum amount of catalyst actually used. Animal quantities of aluminum and other ferrous materials can also be calculated.

Various surface area catalysts such as retrocray, zeolite, silica gel and carbonaceous materials can be used to increase the reaction rate (release) by random mixing with cations. However, using only surface-area catalysts will not actually reduce the concentration of CME or TCE.

The typical minimum temperature at which CME- and TCE-contaminated CACs contact a cation is at least about 50 ° C. and preferably about 70 ° C. Typical maximum temperatures are about 140 ° C., preferably 115 ° C. Temperatures above 140 ° C can be used to accelerate the deposition of CME and TCE, but at these temperatures the quality of the CAC is usually degraded. Of course, ampoule conditions are required at temperatures above 105 ° C (reflux temperature).

The typical minimum residence time is about 15 minutes, preferably about 30 minutes and the maximum residence time is determined in consideration of the actual conditions, but is usually 120 minutes and preferably about 60 minutes. The residence time can, of course, vary with the minimum CME and TCE levels, temperature and catalyst concentration. Reductions in CME and TCE concentrations usually begin within minutes after reaching a typical minimum temperature, which is more evident under surface-area catalysts.

Pressure is not critical to the invention except in relation to temperature. Autogenous pressure is generally sufficient. Preferably the reaction proceeds at reflux (15 ° C., atmospheric pressure) because the reaction rate is reduced under pressure.

Although the present invention relates to a method of releasing CME and TCE from a mixture of CME and TCE and CAC with an initial CAC concentration of about 400-250 ppm and TCE of about 1% by weight (relative to the weight of the CAC).

The present invention is applicable to a state in which the minimum concentration exceeds the amount (eg 1000 ppm CME and 5 wt% TCE) by controlling the catalyst concentration. In general, higher purity requires more catalyst.

The following examples illustrate the invention. Unless otherwise indicated, all and percentages are by weight.

Example 1

CAC (100 g) containing 100 ppm CME and 0.81% TCE was mixed with anhydrous iron chloride (1.4 g). The mixture was refluxed at about 105 ° C. and stirred continuously. Samples were taken at 30 minute intervals and subjected to gas chromatography (GC) analysis.

The results are reported in Table 1.

TABLE I

1 hour salt = start of heating 2 Low detection limit = 0.5 ppm 3 Low detection limit = 0.05% by weight

Example 2-4

Repeating Example 1 with varying concentrations of iron chloride and reaction temperature, the results are reported in Table II.

Example 11

TABLE II

Low detection limit = 0.5 for the weight of the CAC

Zero time = heating start low detection limit = 0.05 weight%

Example 5

[Effect of Hydrochloric Acid on Catalyst Residual Cycle]

CAC (300 g) containing 100 ppm CME and 0.81% TCE was mixed with anhydrous iron chloride (1.1 g) and refluxed at 105 ° C. for 60 minutes with continuous stirring. The crude product (297.4 g) was transferred to scintillation steel and about 285 g of CME and TCE free CAC (purity> 99%) was recovered.

The catalyst residue (8.97 g) was recovered at the bottom of the stills and mixed with clarified CAC (288 g). Clarified CAC contains 100 ppm CME and 0.81% TCE. The mixture was divided into portions in equal portions. The first portion was refluxed at 105 ° C. with continuous stirring for 60 minutes in the presence of HCl.

GC analysis of the crude product revealed that it contained 65 ppm CME and 0.6% TCE.

The second portion was similarly refluxed and stirred but no HCl was added. GC analysis showed 38ppm CME and 0.08% TCE.

These results indicate that the catalytic residue only shows partial activity compared to the purified residue and also that hydrochloric acid is not necessary for the practice of the present invention and, in a sense, adversely affects CAC spinning at reflux.

Example 6 and A-C Control

The samples of CAC (100 g) containing CME (100 ppm) and TCE (0.81%) were mixed with various Lewis acids. The resulting residue was refluxed and stirred for 2 hours, followed by GC analysis. The results are reported in Table III.

TABLE III

^* 90 minutes at 105 ° C and 120 minutes at 85 ° C.

^** Slurry and Lewis acid are not completely dissolved.

Example 7

CAC (100 g) containing CME (100 g) and TCE (0.81%) was mixed with Fe ₂ O ₃ (1.1%). The resulting slurry (all Fe ₂ O _{3 not} dissolved) was refluxed for 2 hours with continued stirring. GC analysis showed about 0.1 ppm of CME and no TCE.

Example 8

Example 7 was repeated using iron deposit instead of Fe ₂ O ₃ and the resulting slurry was refluxed for 90 minutes, then left at 105 ° C. for 2 hours, and then refluxed again at 85 ° C. for 120 minutes. GC analysis showed 8 ppm of CME, 0.45% and TCE.

Example 9

The method of Example 5 was repeated except that the clarified CAC and catalyst residue contained about 3.3% residue and both mixtures were heated under ampoules (temperature above 105 ° C., self-suspension). GC analysis showed that the mixture containing HCl added contained 84ppm CME and 0.54% TCE, while the mixture containing no HCl contained 55ppm CME and 0.71% TCE. This result is in agreement with the result of Example 5, suggesting that the presence of HCl upon CME release has an adverse effect on the ampoule rather than the reflux. This is probably because HCl continues to be removed at reflux, resulting in less HCl than ampoules.

Example 10-13

CAC (100 g) containing 100 ppm of CmE was mixed with various amounts of FeCl ₃ . The resulting mixture was heated at various temperatures under ampoules for several hours and analyzed by GC.

The results are reported in Table IV.

TABLE IV

Example 14

Example 1 was repeated replacing FeCl ₃ with Fe ₂ (SO ₄ ) ₃ . GC analysis after 2 hours showed neither CME nor TCE.

Claims (1)

A mixture of chloroacetyl chloride, bis-chloromethyl ether and 1,1,1,2-tetrachloroethane is contacted with a catalytic amount of iron and aluminum cations at a residence time of 50-140 ° C. and 15-120 minutes. Phosphorus to release bis-chloromethylether and 1,1,1,2-tetrachloroethane.