JP2003128611A - Distillation method of oxystyrene derivative - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel distillation method of an oxystyrene derivative that does not show defects in conventional methods. SOLUTION: The distillation method of an oxystyrene derivative represented by formula (I) (wherein, R represents an alkyl, a haloalkyl, a cycloalkyl, a cycloalkylalkyl, an aryl, especially a phenyl, an aralkyl, especially a benzyl, an alkoxyalkyl, an alkanoyl, an alkoxycarbonyl, an aralkyloxycarbonyl, or an alkylsilyl) is characterized by adding a garbinoxyl as a polymerization inhibitor into the oxystyrene derivative, followed by distillation in the presence of the polymerization inhibitor. This method prevents formation of polymeric materials with high viscosity during the distillation process and distills the oxystyrene derivative with high recovery rate.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for distilling an oxystyrene derivative useful as a raw material for medical and agricultural chemicals, functional polymers, polymer synthesis, etc. for the purpose of purification after its synthesis.

[0002]

2. Description of the Related Art Among oxystyrene derivatives, for example, p
-Tert-butoxystyrene (hereinafter referred to as "PTBST"
Abbreviated. "PTBST" is a registered trademark of the applicant. ) Is
It is known to be useful as a resist material used for VLSI applications and the like (JP-A-59-19970).
No. 5, JP-A-3-277608), and m
-Tert-butoxystyrene (hereinafter referred to as "MTBST"
Abbreviated. "MTBST" is a registered trademark of the applicant. ) Is
It is known to be useful as an intermediate raw material for functional polymers, pharmaceuticals and agricultural chemicals (JP-A-2-160739).

As a method for synthesizing an oxystyrene derivative,
The following methods are known. For example, PTBST
Tert-Butoxystyrene such as MTBST is prepared by synthesizing a Grignard reagent from halogen-substituted styrene such as chlorostyrene, bromostyrene and iodostyrene and magnesium, and then reacting this with tert-butyl perbenzoate. (JP-A-59-199705) is known.

Further, tert-butoxyphenyl chloride, tert-butoxyphenyl bromide, ter
A method of synthesizing a Grignard reagent from tert-butoxyphenyl halide such as t-butoxyphenyl iodide and magnesium, and then coupling this to vinyl halide such as vinyl chloride or vinyl bromide. No. 71896, JP-A-2-160739) are known.

In the method for synthesizing the oxystyrene derivative as described above, the synthesized target compound is usually separated and purified by distillation. However, since the oxystyrene derivative is generally polymerized by light or heat to form a highly viscous liquid polymeric substance, the product recovery rate during distillation may be significantly reduced. Further, due to the generated polymeric substance in the distillation column, in the distillation can, in the pipe, etc., blockage of the distillation column or the pipe, abnormality in the degree of reduced pressure due to the above,
This may cause troubles such as difficulty in cleaning due to adhesion of the polymeric substance. Therefore, in order to avoid these troubles, it has been customary to add various polymerization inhibitors to the oxystyrene derivative and carry out the distillation operation in the presence thereof. As the method, for example, in the distillation of tert-butoxystyrene such as PTBST or MTBST, a method of performing distillation in the presence of 4-tert-butylcatechol (Japanese Patent Publication No. 4-7189).
No. 6, JP-A-2-160739), N-nitrosophenylhydroxylamine aluminum salt, N
A method is known in which distillation is carried out in the presence of -nitrosophenylhydroxylamine ammonium salt, 2,4-dinitrophenol or the like (Japanese Patent Laid-Open No. 2000-327617).

However, the above-mentioned conventionally used polymerization inhibitors do not show a sufficient inhibitory effect on the formation of the polymeric substance under the severe conditions of long time and high temperature in the distillation step of the oxystyrene derivative, so that they are not highly effective. A viscous polymeric substance is formed, which causes troubles such as blockage of the distillation column or piping in the distillation column or distillation can, abnormal pressure reduction due to the above, and difficulty in cleaning due to adhesion of the polymeric substance. Often. Even if such trouble does not occur, there is always a problem that the yield of the product after distillation is reduced. for these reasons,
Conventional distillation methods for oxystyrene derivatives have not been satisfactory.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a new distillation method for oxystyrene derivatives which can overcome the drawbacks of the conventional methods. In other words, there is almost no formation of a polymeric substance that occurs in the conventional method, and even when the distillation operation for a long time is performed, the P recovery is high.
It is to provide a novel distillation method capable of purifying oxystyrene derivatives such as TBST and MTBST.

[0008]

[Means for Solving the Problems] The inventors of the present invention have conducted extensive studies to solve the above problems. As a result, in the distillation step of the oxystyrene derivative, by adding galvinoxyl as a polymerization inhibitor and distilling in the presence thereof, without causing the formation of a polymeric substance,
It was found that the oxystyrene derivative can be distilled with a high recovery rate. The present invention has been completed based on this finding.

Therefore, in the present invention, the following general formula (I) is used with galvinoxyl as the polymerization inhibitor.

[Chemical 2] (In the formula, R represents an alkyl group, a haloalkyl group, a cycloalkyl group, a cycloalkylalkyl group, an aryl group, particularly a phenyl group, an aralkyl group, particularly a benzyl group, an alkoxyalkyl group, an alkanoyl group, an alkoxycarbonyl group, an aralkyloxycarbonyl group. Group or an alkylsilyl group) is provided, and a method for distilling an oxystyrene derivative is provided.

The method of the present invention will be described in detail below.

The oxystyrene derivative to be distilled in the present invention can be effectively used as long as it is contained in the general formula (I). These are known methods (for example, Japanese Patent Publication No. 4-71896). Method) or according to a known method.

Specific examples of the oxystyrene derivative of the general formula (I) to be distilled in the method of the present invention include:
For example: p-methoxystyrene,
p-ethoxystyrene, pn-propoxystyrene,
p-isopropoxystyrene, pn-butoxystyrene, p-isobutoxystyrene, p-sec-butoxystyrene, p-tert-butoxystyrene, pn-
Amyloxystyrene, p-isoamyloxystyrene, p-sec-amyloxystyrene, p-tert
-Amyloxystyrene, p-cyclopropyloxystyrene, p-cyclopropylmethyloxystyrene, p
-Cyclobutyloxystyrene, p-cyclopentyloxystyrene, p-cyclohexyloxystyrene, p
-Trifluoromethoxystyrene, p-pentafluoroethoxystyrene, p-chloromethoxystyrene, p-
(2-chloroethoxy) styrene, p-bromomethoxystyrene, p- (2-bromoethoxy) styrene, p-
Phenyloxystyrene, p- (4-methylphenyloxy) styrene, p- (4-fluorophenyloxy)
Styrene, p- (4-chlorophenyloxy) styrene, p- (4-bromophenyloxy) styrene, p-
(4-Methoxyphenyloxy) styrene, p- (4-
Ethoxyphenyloxy) styrene, p- (4-ter
t-butoxyphenyloxy) styrene, p- (4-nitrophenyloxy) styrene, p-benzyloxystyrene, p- (4-methylbenzyloxy) styrene,
p-methoxymethoxystyrene, p- (1-ethoxyethoxy) styrene, p- (2-tetrahydropyranyloxy) styrene, p-acetoxystyrene, p- (te
(rt-butylcarbonyloxy) styrene, p-benzyloxycarbonyloxystyrene, p-methoxycarbonyloxystyrene, p- (tert-butoxycarbonyloxy) styrene, p-trimethylsilyloxystyrene, p-tert-butyldimethylsilyloxystyrene, etc. Is mentioned. Instead of the oxystyrene derivative having a para-substituted phenyl group, an oxystyrene derivative having a corresponding meta-substituted phenyl group can be used.

Galbinoxyl (2,6-di-tert-butyl-α- (3,5-di-tert-butyl-4-oxo-2,5-cyclohexadiene) used as a polymerization inhibitor in the method of the present invention. -1-Ylidene) -p-
Trilyloxy) is a compound represented by the following formula (II).

[Chemical 3] (In the formula, t-Bu represents a tert-butyl group.)

This galvinoxyl is a known compound and is known by a known method (for example, Angew. Makromo).
l. Chem. Volume 200, pp. 147-161 (1992)), or a commercially available product.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is carried out as follows. That is, immediately after the oxystyrene derivative of the general formula (I) to be distilled is produced, the polymerization inhibitor galvinoxyl is added. After this, a distillation operation may be performed.

The preferred addition amount of galvinoxyl used in the method of the present invention is determined by the kind of the substituent R of the oxystyrene derivative of the formula (I) to be distilled, the distillation temperature and the distillation pressure, and determined experimentally. However, in general, the amount of the oxystyrene derivative of the formula (I) to be distilled is 10 to 100,000 ppm, preferably 100 to 100 ppm.
It is in the range of 10,000 ppm. Distillation temperature is usually 2
The temperature is 0 to 200 ° C, preferably 40 to 150 ° C. The oxystyrene derivative is usually distilled under reduced pressure, usually 0.0001 to 500 mmH.
g, preferably under a pressure of 0.0001 to 10 mmHg.

[0017]

The present invention will be described in more detail based on the following examples, but the invention is not intended to be limited by these examples.

Example 1 In a four-diameter flask equipped with a distillation condenser, a thermometer and a stirrer, 100 g of PTBST (p-tert-butoxystyrene) immediately after being synthesized by the method of Japanese Patent Publication No. 4-71896 was used to inhibit polymerization. Galvinoxyl as an agent 0.0
The mixture formed by adding 5 g (concentration of 500 ppm) was charged. This mixed solution is heated at 130 ° C. in a flask at 5 mmH.
It was distilled under a reduced pressure condition of g for 48 hours with stirring. By this distillation step, 95.0 g of PTBST was distilled from the flask. At the bottom of the flask, about 5.0 g of highly viscous liquid substance remained without being distilled. The recovery rate (%) of PTBST that could be recovered by distilling from the flask was calculated by the following formula.

[0019]

[Equation 1]

The measured values of the recovery rate (%) obtained are shown in Table 1 below.

Example 2 MTB in place of the distilled PTBST used in Example 1
The same distillation step as in Example 1 was operated except that ST (synthesized by the method described in JP-A-2-160739) was used.

Comparative Example 1 A distillation step was carried out in the same manner as in Example 1 except that the known polymerization inhibitor N-nitrosophenylhydroxylamine aluminum salt was used in place of the galvinoxyl used as the polymerization inhibitor in Example 1. Operated.

Comparative Example 2 Except that p-tert-butylcatechol was used instead of galvinoxyl used as the polymerization inhibitor in Example 2.
The distillation process was operated in the same manner as in Example 2.

[0024]

[Table 1]

[0025]

When the present invention is carried out, the following effects are brought about. That is, formation of a highly viscous polymeric substance is prevented during the distillation process, and the recovery rate of the distilled oxystyrene derivative is high. Therefore, the method for distilling an oxystyrene derivative of the present invention solves various problems of the conventional distilling method and is highly useful as an industrial method.

Claims (2)

[Claims] 1. A compound represented by the following general formula (I): wherein galvinoxyl is used as a polymerization inhibitor. (In the formula, R represents an alkyl group, a haloalkyl group, a cycloalkyl group, a cycloalkylalkyl group, an aryl group, particularly a phenyl group, an aralkyl group, particularly a benzyl group, an alkoxyalkyl group, an alkanoyl group, an alkoxycarbonyl group, an aralkyloxycarbonyl group. Group or an alkylsilyl group) is distilled, the oxystyrene derivative is distilled. 2. The oxystyrene derivative to be distilled is te
The distillation method according to claim 1, which is rt-butoxystyrene.