JPH01211547A - Purification of acyl halide - Google Patents

Abstract

PURPOSE:To obtain the above compound which is a reactive acylation agent useful as an intermediate raw material for reaction, in high purity and excellent color tone, by contacting activated carbon with crude acyl halide free from volatile component, thereby removing impurities from the acyl halide under mild condition in high efficiency without lowering the quality of the product. CONSTITUTION:Crude acyl halide heat-treated at 20-80 deg.C for 0.5-4hr under normal or reduced pressure to remove volatile components is purified with activated carbon. The preferable activated carbon is those produced by using bituminous coal, brown coal, peat, wood waste, etc., as a raw material and having pores of 10-150Angstrom in diameter, e.g., granular Shirasagi S (product of Takeda Chem. Ind.),. The amount of activated carbon is preferably 2-10wt.% based on the acyl halide in the case of using the carbon by adding to the acyl halide. As an alternative method, acyl halide is purified by passing through a column packed with the activated carbon. The purification temperature is preferably 40-100 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for purifying acyl halides, and more specifically to a method for refining crude 7-sylparide, from which volatile components have been removed in advance, using activated carbon.

(Prior art) Acyl halide is a highly reactive acylating agent and is a useful substance in emergency situations.As its applications have expanded in recent years, it has become a high-quality reaction intermediate raw material, for example, as a cause of coloration and cloudiness in the final product. The quality required of acyl halides, such as low impurities, is increasing year by year.

Conventionally, many methods have been known for producing acylparite by reacting carboxylic acids with various halogenating agents. For example, (A) method using phosphorus pentachloride (J, Am, Che
m, Soc, 67.2239 (1954)), (B)
Method using phosphorus trichloride (J, Chem, Soc, 2
030 (1954)), (C) Method using phosphorus oxychloride (Yoi Kagaku, Vol. 10, No. 7, 435 (1961))
, (D) Method using thionyl chloride (J, Chem.

5oc0.2117 (1953)), (E) Method using phosgene (J, Chem, Soc, * 31.15
1 (1954)).

In addition, the present applicant has applied for methods for purifying acyl halides, such as (F) a method using a separation membrane (Japanese Patent Application No. 62-131542) and (G) a method using an inorganic adsorbent (Japanese Patent Application No. 62-206248). ing.

[Problem to be solved by the invention]

In order to produce a highly pure acyl halide, phosgene or thionyl chloride is often used as K because the by-product is gaseous and can be easily removed from the system. However, in the reaction using phosgene, although lower carboxylic acids show high reactivity, higher carboxylic acids have low reactivity and require high reaction temperatures, resulting in poor hue of the acyl halide obtained. There are drawbacks. Furthermore, phosgene is an extremely toxic gas, and safety measures have become a major social issue. In this respect, the use of thionyl chloride is industrially advantageous, but as with phosgene, it requires the use of a reaction catalyst and has problems such as the unavoidable recovery and removal process. Furthermore, these are economically expensive reaction reagents that have a small number of effective halogens per molecule required for acylation of carboxylic acids.

On the other hand, halogenated phosphorus compounds have a larger number of effective halogens than these, making them economically advantageous reagents, and because the reaction conditions are mild, the resulting acyl halide has a good hue, making it an industrially advantageous production method. It is. However, when a reaction is carried out using phosphorus trichloride, for example, most of the by-product phosphorus compounds can be easily separated and removed from the acyl halide, but a portion remains in the acyl halide, resulting in a cloudy final product. There are quality problems such as coloring and discoloration.

The present invention aims to solve the conventional problems with respect to acyl halide obtained by the reaction of a halogenated phosphorus compound and a carboxylic acid, and to obtain a highly pure acyl halide with a good hue in high yield.

[Means to solve the problem]

The present invention is a method for purifying acyl halide, which is characterized by bringing crude acyl halide, from which volatile components have been removed in advance, into contact with activated carbon under normal pressure or reduced pressure.

The acyl halide purified in the present invention is a reaction product of a carboxylic acid and a phosphorus halide compound such as phosphorus trichloride, phosphorus pentachloride, phosphorus tribromide, phosphorus pentabromide, phosphorus oxychloride, or phosphorus oxybromide, and is an impurity. Contains phosphorus compounds.

Carboxylic acids used as raw materials include saturated aliphatic carboxylic acids such as piparic acid, cabroic acid, caprylic acid,
-Ethylhexane*, nonanoic acid, 2,2-dimethyloctanoic acid, capric acid, lauric acid, myristic acid, valmitic acid, stearic acid, behenic acid, etc., as unsaturated aliphatic carboxylic acids, acrylic acid, methacrylic acid, onine Aromatic carboxylic acids such as linoleic acid, lylunic acid, erucic acid, benzoic acid, phenylacetic acid, phenylpropionic acid, cinnamic acid, etc. Dicarboxylic acids such as succinic acid, adipic acid, phthalic acid, isophthalic acid, Examples include terephthalic acid and mixtures of two or more of these.

The activated carbon used in the present invention is obtained from bitumen, lignite, peat, coconut shells, pecan shells, petroleum residues, black ash from bulp factories, wood chips (spy), etc.
It has 50A pores and can be used alone or as a mixture of two or more. Furthermore, other inorganic compounds, such as alkaline earth metal hydroxides, alkaline earth metal oxides, hydroxides of group (I) elements, or their alkali metal salts, alkaline earth metal salts, and aluminum salts, or It can also be used in combination with a mixture of

Activated carbon can be prepared using known methods such as J.W.
Activated carbon" may be manufactured by the method described in Kyoritsu Shuppansha (1966), or may be selected from general commercially available products.
The activated carbon used in the present invention has an activation temperature of 300 to 1000°C.
1 Preferably, it is activated carbon activated at 500 to 1000°C. The activation method is not particularly limited, but the activation temperature is 30
Activated carbon obtained at temperatures below 0°C has insufficient adsorption capacity;
Further, when the activation temperature is higher than 1000°C, the adsorption capacity of the obtained activated carbon rapidly decreases, so that the remarkable effects of the present invention cannot be obtained. Although the shape of activated carbon is not particularly limited, it is desirable to dry and dehydrate it sufficiently before use.

As a preferred activated carbon, Ota Pharmaceutical Co., Ltd. Granular Shirasagi S1
Granular Shirasagi W, Shirasagi A, Shirasagi C, etc., made by Kuraray Chemical ■ Rarecol GW, Crancor GL, Tararecol K
There are W, etc.

In carrying out the present invention, the crude acyl halide to be purified is one from which volatile components have been previously removed under normal pressure or reduced pressure. The volatile components are mainly unreacted halogenated phosphorus compounds, and if a considerable amount of these halogenated phosphorus compounds remain, the adsorption ability of activated carbon is significantly inhibited, and the effects of the present invention cannot be obtained. This removal of volatile components can be carried out by heating the crude acyl halide to 20 to 80°C for 0.5 to 4 hours under normal pressure or reduced pressure.

In the present invention, when the activated carbon is added to the acyl halide, the amount of activated carbon used is 1 to 15% based on the acyl halide.
A weight ratio is preferable, and a weight ratio of 2 to 10 weight ratio is more preferable. If the amount of activated carbon used is less than 1, the effect of removing impurities will be insufficient, and if it exceeds the 1S ratio, the amount of acyl halide adsorbed onto the activated carbon will increase, which is economically disadvantageous.

On the other hand, in putting the present invention into practice, acyl halide can also be purified by introducing it into a column packed with activated carbon. The activated carbon used is preferably a molded product such as granules or pellets, and the introduction rate of 7silparide (LH8V) is 0.
．． 5-2. □h-1 is preferred. LH8V is 0.5h-
If it is less than 1, the removal of impurities is insufficient, and 2, 'oh
- Exceeding the limit requires a long time and is economically disadvantageous.

The purification temperature of the present invention is 40 to 200°C, preferably 40°C to 200°C.
0~ZOO°C. If the temperature is less than 40°C, it will take a long time for purification, which is economically disadvantageous, and if it exceeds 200°C, the decomposition of the acyl halide will be accelerated.

The purification time of the present invention is 0.5~
4 hours is sufficient. Less than 0.5 hours is not efficient.

In the present invention, a commercially available glass filter, filter paper, microfiltration membrane, centrifugal separator, etc. can be used to separate the acyl halide and activated carbon.

(Effects of the Invention) According to the method of the present invention, since the purification conditions are mild, there is extremely little deterioration in the quality of acyl halide, impurities can be efficiently removed, and high purity and high quality acyl halide with good color can be produced. can be obtained in good yield.

〔Example〕

Production Example Lauric acid 800I dissolved in a 2-volume, 4-port liquid 0-1 liquid was charged, and the mixture was heated to 55° C. without stirring. After raising the temperature, 276 J' (0.5 times the mole) of phosphorus trichloride was added dropwise in a nitrogen atmosphere over 1 hour, and after the dropwise addition was completed, the mixture was further aged for 2 hours. Thereafter, the mixture was allowed to stand at the same temperature for 1 hour to remove precipitated phosphorous acid. Subsequently, the pressure was vigorously reduced to 10 mmHg at the same temperature, and the mixture was stirred for 4 hours to obtain crude lauric acid chloride 840P.

In addition, crude oleic acid chloride was obtained in the same manner.

Examples 1 to 6 100 J' of the crude lauric acid chloride obtained in the above production example was placed in three 200 ml volume flasks equipped with a stirrer and a thermometer.
5.10 and 20% by weight of granular activated carbon (Kuraray Coal KW 10-32 Metsushi S) activated at 800°C were added to it, and 60% by weight was added to it under a nitrogen atmosphere.
The mixture was stirred at °C for a specified time. Thereafter, the activated carbon was filtered off to obtain purified lauric acid chloride.

Purified oleic acid chloride was also obtained in the same manner.

The results obtained are shown in Table-1.

Examples 7-10 Crude lauric acid chloride 1 obtained in the same manner as in the production example
00J'IC, 300, 500, 800, and 110
Coconut shell granular activated carbon (10-32
10 parts by weight of Mesh) were added, and the mixture was purified in the same manner as in Example 1.

The results obtained are shown in Table-2.

Examples 11-14 Crude lauric acid prid 1 obtained in the same manner as in the production example
00/, 10% by weight of granular activated carbon (Kuraray Coal GW; 10-32 mesh) activated with SOO''C was added,
20.60, 100, and 20.60, respectively, in the same manner as in Example 1.
Purified at 230°C.

The results obtained are shown in Table 3.

Example 15 Granular activated carbon (Kuraray Coal GW; 10 to 32 mesh) activated at 80°C in a stainless steel column equipped with a hot water jacket with an inner diameter of 2.54 cm and a length of 30.5 cIL.
35J' (filling density = 0.48) was filled, and 80°C hot water was circulated to warm the inside of the system. The hue obtained in the same manner as the production example was APHA20, and the phosphorus content was 1271p.
pm of crude lauric acid chloride (a:'=o, 92) was added using a metering pump at a flow rate of 80 ml/h (LH8V=
0.97 (v/v)h-').

When 360 J' of crude lauric acid chloride was introduced, 291 J' of purified lauric acid chloride was obtained. The hue of the purified lauric acid chloride obtained was APRA15,
The phosphorus content was 21 ppm.

As is clear from the results of the examples, it can be seen that by-product phosphorus compounds can be considerably removed by purification using the activated carbon of the present invention. It can be seen from the examples in Table 2 that the activation temperature of activated carbon is preferably 300 to 1°00"C, more preferably 500 to 1000"C. Also, from the examples in Table 3, the purification temperature of the present invention is 40~200°
It can be seen that C is preferable.

The phosphorus content of the acyl halides obtained by the purification of the present invention is 300 ppm or less, the hue of lauric acid chloride is APHA 20 or less, and the hue of oleic acid chloride is APHA 20 or less.
It was 90. Moreover, the yield of each acyl halide was 90 or higher in all cases except for Example 15.

As shown in 5 above, it can be seen that high quality acyl halides with good hue can be obtained in high yield by the method of the present invention.

Patent applicant: NOF Corporation

Claims (1)

[Claims] 1. A method for purifying acyl halide, which comprises contacting crude acyl halide from which volatile components have been removed with activated carbon.