JP3139066B2 - Method for producing amide by liquid phase rearrangement of oxime - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a process for producing an amide by rearrangement of an oxime and a catalyst thereof.

[0002]

BACKGROUND OF THE INVENTION The rearrangement of an oxime to an amide is known as the Beckmann rearrangement. For example, in industrial production of ε-caprolactam by rearrangement of cyclohexanone oxime, fuming sulfuric acid is used as a catalyst. However, in this method, a large amount of ammonium sulfate is produced as a by-product, and there are many process problems such as corrosion of the apparatus.
The development of an efficient rearrangement catalyst is expected.

[0003] For example, solid oxide catalysts in which boron oxide is supported on silica, alumina or titania, and zeolite catalysts have been proposed. When these solid catalysts are used for a rearrangement reaction, high-temperature gas phase reaction conditions must be used. Since it is necessary to employ the compound, the yield of ε-caprolactam decreases, the catalyst deteriorates, and the energy cost increases.

[0004] On the other hand, there have been known several methods for obtaining ε-caprolactam by rearranging cyclohexanone oxime under relatively mild reaction conditions such as a liquid phase reaction. One is N,
This method uses an ion pair (Vilsmeier complex) obtained by the reaction between N-dimethylformamide and chlorosulfonic acid as a catalyst (MAKira and YMShaker, Egypt. J. Chem.,
16, 551 (1973)). However, this method is described as requiring a catalyst in an equimolar amount with the oxime since the formed lactam and the catalyst form a 1: 1 complex, which is not economical.

An alkylating agent obtained from an epoxy compound and a strong acid (boron trifluoride / etherate, etc.)
Liquid phase Beckmann rearrangement using a catalyst composed of N, N-dialkylformamide is also known (Y. Izumi, Chemist
ry Letters, pp.2171 (1990)). This method discloses an excellent new rearrangement method, but requires an epoxy compound as an alkylating agent used as a component of the rearrangement catalyst, and requires an unstable solvent such as dimethylformamide.
It is not always industrially satisfactory in terms of economy and operability.

Further, Japanese Patent Application Laid-Open No. 62-149665 discloses a method for producing ε-caprolactam by rearranging cyclohexanone oxime in a heptane solvent using phosphoric acid. On the other hand, it is necessary to use about twice as much molar amount of phosphoric acid,
Therefore, it is described that ammonia is neutralized after the reaction, and phosphoric acid is recovered and reused through a complicated process.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a novel method for producing an amide by rearrangement of an oxime under a liquid phase condition.

The inventors of the present invention have conducted intensive studies on a catalyst for rearranging an oxime to an amide. As a result, when the oxime is heated in the presence of a perrhenate and a strong acid or a derivative thereof, the rearrangement produces an amide. And arrived at the present invention.

[0009]

That is, the present invention is a process for producing an amide, which comprises rearranging an oxime in the presence of a perrhenate and a strong acid or a derivative thereof.

The amount of the perrhenate and the strong acid or a derivative thereof is not particularly limited, but is usually about 2 to 20 mol% of the oxime. Examples of the perrhenate used in the present invention include ammonium perrhenate, tetramethylammonium perrhenate, tetraethylammonium perrhenate, tetrabutylammonium perrhenate and ventilammonium perrhenate.

The strong acids or derivatives thereof used in the present invention include p-toluenesulfonic acid, methanesulfonic acid,
sulfonic acids such as m-nitrobenzenesulfonic acid, trifluoromethanesulfonic acid and trifluoromethanesulfonic anhydride, ethyl trifluoromethanesulfonate, trimethylsilyl trifluoromethanesulfonate, boron trifluoride, boron trifluoride / ether complex, pentafluoride And inorganic strong acids such as antimony and phosphoric anhydride.

The present invention can be applied to known oxime compounds without any limitation. Specific examples of the oxime compound include cyclohexanone oxime, cyclopentanone oxime, cyclododecanone oxime, acetone oxime, 2-butanone oxime, acetophenone oxime,
Benzophenone oxime and the like. Especially, it is preferably applied to cyclic oximes such as cyclohexanone oxime, cyclopentanone oxime and cyclododecanone oxime.

The rearrangement reaction of the oxime of the present invention is usually carried out in the presence of a solvent. Although the solvent is not particularly limited, aromatic hydrocarbons such as monochlorobenzene, o-dichlorobenzene, and nitrobenzene; 1,2,3-trichloropropane, tetrachloroethylene, and 1,1,2,2-tetrachloroethane; Chlorinated aliphatic hydrocarbons are preferably used. 1,2,3-trichloropropane, 1,1,2,2
The use of 2-tetrachloroethane or nitrobenzene is particularly preferred because the yield is improved.

In the present invention, the reaction is usually carried out by mixing an oxime, a perrhenate and a strong acid or a derivative thereof dissolved in a solvent, followed by heating. The reaction is usually performed at about 100 to 15
Performed at 0 ° C. After completion of the reaction, an alkali neutralization treatment is carried out according to a conventional method, and the amide is separated by distillation.

[0015]

EXAMPLES The present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

Example 1 A flask was charged with 50.3 mg (0.445 mmol) of cyclohexanone oxime dissolved in 2 ml of monochlorobenzene.
l) was charged. Next, 23.80 mg (0.048 mmol) of tetrabutylammonium perrhenate (Inorganic Synt) dissolved in 1.5 ml of monochlorobenzene
hesis 26,391 (1989). ) And 8.30 mg of paratoluenesulfonic acid (0.044 mm
ol). The reaction was performed under reflux for 11 hours. After completion of the reaction, the reaction mixture was neutralized by adding a saturated solution of sodium hydrogen carbonate, stirred with ethyl acetate, and the catalyst was separated by filtration. did. The yield of ε-caprolactam is 45
%Met.

Examples 2 and 3 Equimolar to cyclohexanone oxime (0.445 mmol)
l) The procedure of Example 1 was repeated except that water or N, N-dimethylformamide of l) was added. The yields of ε-caprolactam were 36% and 46%, respectively.

Example 4 10 ml of monochlorobenzene, 110 mg of tetrabutylammonium perrhenate, p-
Toluenesulfonic acid monohydrate 42mg (0.223mm
ol) and 250 mg of cyclohexanone oxime (2.
23 mmol) and reacted under reflux for 2 hours. After completion of the reaction, the mixture was neutralized by adding a 1% sodium hydroxide solution. As a result of analysis by gas chromatography, the conversion of cyclohexanone oxime was 84.9%, and the yield of ε-caprolactam was 31.9%.

Example 5 Strong acid or its derivative shown in Table 1 (0.223 mmol)
Example 4 was carried out except that was used. Table 1 shows the results.

Example 6 The same procedure as in Example 4 was carried out except that trifluoromethanesulfonic anhydride was used as a strong acid or a derivative thereof and 1,2,3-trichloropropane was used as a solvent at a reaction temperature of 130 ° C. and 120 ° C. went. Table 2 shows the results.

The procedure was carried out in the same manner as in Example 4 except that trifluoromethanesulfonic anhydride was used as the strong acid or its derivative, the reaction temperature was 120 ° C., and 1,1,2,2-tetrachloroethane or nitrobenzene was used as the solvent. . Table 3 shows the results.

Comparative Example 1 Example 4 except that p-toluenesulfonic acid was not added.
The same was done. The oxime conversion was 9.3% and the lactam yield was 4.9%.

Comparative Example 2 The procedure of Example 4 was repeated except that tetrabutylammonium perrhenate was not added. Oxime conversion is 7
3.1%, lactam yield was 3.4%.

[0024]

[Table 1]

[0025]

[Table 2]

[0026]

[Table 3]

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C07D 223/10 B01J 27/12 B01J 31/02 103 C07B 61/00 300 CA (STN)

Claims (4)

(57) [Claims] 1. A process for producing an amide, which comprises rearranging an oxime in the presence of a perrhenate and a strong acid or a derivative thereof. 2. The method for producing an amide according to claim 1, wherein the perrhenate is tetrabutylammonium perrhenic acid. 3. The strong acid or a derivative thereof is p-toluenesulfonic acid, methanesulfonic acid, m-nitrobenzenesulfonic acid, trifluoromethanesulfonic acid, trifluoromethanesulfonic anhydride, ethyl trifluoromethanesulfonic acid, trimethylsilyl trifluoromethanesulfonic acid, Boron trifluoride, boron trifluoride ether complex,
The method for producing an amide according to claim 1, wherein the amide is at least one compound selected from the group consisting of antimony pentafluoride and phosphoric anhydride. 4. The method for producing an amide according to claim 1, wherein the reaction solvent is 1,2,3-trichloropropane, 1,1,2,2-tetrachloroethane or nitrobenzene.