JPS58174375A - Production of 2,3-dihydro-2,2-dimethyl-7- hydroxybenzofuran - Google Patents

Abstract

PURPOSE:The rearrangement and cyclization of o-methallyloxypenol is carried out in the presence of a mixture of AlI3 or AlCl3 with an N-substituted aniline derivative, or a complex thereof to give the titled substance economically in high yield. CONSTITUTION:In the rearrangement and cyclization of o-methallyloxyphenol into the titled substance, AlI3 or AlCl3 and a compound of formula I (R<1>, R<2> are 1-6C alkyl, phenyl, or incorporate to represent 5-7C alkylene; R<3> is H, 1-8C alkyl) or their complex is used as a catalyst and a compound of formula I , aromatic hydrocarbon, aliphatic hydrocarbon, aromatic ether or aliphatic ether is used as solvent, the reaction temprature and pressure are set to 60- 250 deg.C and atmospheric pressure, thus facilitating reaction facilities.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process for producing 2,3-sibaido-2,2-dimethyl-7-hydroxybenzofuran using ortho-methallyloxyphenol as a raw material.

2.3-Sibidrow 2,2-dimethyl-7-hydroxybenzofuran is a compound known as a raw material for carborane insecticides, and it is known that carborane is produced by converting this compound into methyl carbamate.

Conventionally, ortho-methallyloxyphenol (hereinafter referred to as
Various methods have been developed for producing 2,3-sibaido-2,2-dimethyl-7-hydroxybenzofuran (hereinafter also referred to as oleopenzofuranol) using 2,3-sibaido-2,2-dimethyl-7-hydroxybenzofuranol (also referred to as monoether) as a raw material.

Generally, benzofuranol is
8 and Japanese Patent Publication No. 42-12268, monoether was synthesized by heating to about 200°C, but the yield in this case was low and did not reach 50%. Afterwards, these improved methods were studied and published in JP-A-55-7.
No. 6870 describes a method in which monoether is heated to 170 to 230°C in the presence of water and, if necessary, a specified organic solvent. In JP-A-56-16484, imbutenylpyrocatechol is heated to 60 to 200°C in the presence of a sulfonic acid. In JP-A-56-29584, a method has been developed in which the etherification, rearrangement, and cyclization reactions of pyrocatechol are carried out in the presence of a specific polyhydroxyalkyl ether.

The present inventors have sufficiently studied the above-mentioned conventional method, and further,
As a result of intensive studies aimed at further improving the overall yield from monoether to benzofuranol family, we found that TA + tnium chloride or aluminum chloride and N- were used as catalysts.
We have established a method for economically producing benzofuranol in high yield by using a substituted aniline derivative or a complex of the solid compound described above.

That is, the present invention provides 2,8-dihydro 111.
! - When obtaining dimethyl-7-hydroxybenzofuran, aluminum sulfide or aldenium chloride is used as a catalyst and the general formula (IRI, R1 has 1 carbon number) is used as a catalyst.
-6 alkyl group, phenyl group, or R1 and R8 are combined to form an alkylene group having S to 7 carbon atoms, R1 is hydrogen or an alkyl group having 4 carbon atoms); g,3-dihydro 1. characterized by using a complex of this solid compound. ! -Relating to a method for producing dimethyl-7-hydroxybenzofuran.

The above-mentioned rearrangement and cyclization reactions of the present invention are carried out using the following reaction formula % Formula % In the present invention, aluminum iodide or aluminum chloride is used as a catalyst, and N-
Substituted aniline derivatives or complexes of this solid compound are used. As the above complex, aluminum iodide or aluminum chloride and an N-substituted aniline derivative may be added separately to form a complex in the system, or a complex of a solid compound synthesized in advance may be used. good. A complex of aluminum iodide or aluminum chloride and an N-substituted aniline derivative is usually formed by using the latter in a ratio of about 1 mol or more per 1 mol of the former.

Aluminum iodide is preferably used in a proportion of from about 0.001 to 0.8 parts by weight, particularly preferably from about 0.001 to 0.08 parts by weight, per part by weight of monoether. Aluminum chloride is preferably used in a proportion of about 0.001 to 0.5 parts by weight per part by weight of monoether;
It is particularly preferably used in a proportion of about 0.005 to 0.05 parts by weight. , aluminum iodide and aluminum chloride can be used in the presence of crystallization water, but anhydrous forms are preferred. Suitable examples of the N-substituted aniline derivative represented by general formula (1) include N,N-dimethylaniline, N,N
-diethylaniline, N-methyl-diphenylamine,
N,N-dimethyl-p-)cyidine 1. N-phenylpiperidine and the like can be mentioned.

In the present invention, the reaction can preferably be carried out using a solvent. Suitable solvents include N-substituted aniline derivatives represented by the above general formula (1), aromatic hydrocarbons, aliphatic hydrocarbons, aromatic ethers, and aliphatic ethers. Specific examples of the aromatic hydrocarbons mentioned above include benzene, toluene, xylene, diethylbenzene, -□triethylbenzene, naphthalene, tetralin, diphenylethane, etc., and specific examples of the aliphatic hydrocarbons include hexane, heptane, Octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, pentadecane, hexadecane, heptadecane, decalin, etc., and specific examples of aromatic or aliphatic ethers include diphenyl ether, ani'/-)Lt, -jf
Examples of such solvents include "ruphenyl ether." Such solvents can be used alone or in combination, and are usually about 1 to 50 parts by weight, preferably about 5 to 25 parts by weight, per 1 part by weight of monoether. used in proportion.

In the present invention, the temperature is usually about 60 to 250°C, preferably about 100°C.
It is carried out in a temperature range of ~210°C. Also, batch type,
Any continuous method can be used.

In the present invention, the intermediate rearrangement product □...1 acid, namely 3-methallyl-1,2-dihydroxybenzene and 3-imbutenyl-1,2-dihydroxybenzene, is converted into benzofuranol. The present invention provides a method for producing benzofuranol directly from monoether in a two-step process in high yield with H in g tB without providing a purification step for these intermediates. .

Furthermore, a major feature of the present invention is that either normal pressure or pressurized methods can be adopted in this method, and in particular, by conducting the reaction at normal pressure, the equipment can be simplified, making it economical. benzofuranol can be produced in extremely high yields.

Next, embodiments of the present invention will be specifically described. The monoether, catalyst, and solvent may be added in any order and then heated, or aluminum iodide or aluminum chloride and the N-substituted aniline derivative represented by general formula (1) may be mixed to form a complex. After cooling, a solvent and a monoether may be added and heated.

The reaction rate of the present invention is fast, and the reaction is usually completed in several tens of minutes to several hours. After the reaction, the obtained benzofuranol can be isolated by distillation, etc., and when benzofuranol is used as a raw material to further synthesize other compounds, it can be used as is for reaction without isolation. can.

The present invention will be explained below with reference to Examples.

Example 1 Capacity 30 with thermometer, stirrer and reflux condenser
N,N-dimethylaniline 2002 was placed in a 0 ml/g glass reactor, and the air in the system was replaced with nitrogen gas. Next, add 0.67 g of aluminum iodide and stir. 16.4 g (100 mmol) of monoether was added to this, and the mixture was heated at reflux temperature for 1 hour with stirring.

As a result of high performance liquid chromatography analysis of this reaction solution, 18.8F (84 mmol) of benzofuranol was obtained.

Furthermore, the nuclear magnetic resonance spectrum and mass spectrum of the fraction obtained by distilling this reaction solution under reduced pressure completely matched the spectrum of a separately synthesized standard benzofuranol, confirming its identity.

Examples 2 to 6 Using the same reactor as in Example 1, the system was placed under a nitrogen gas atmosphere, and 16.49 (100 mmol) of monoether, an N-substituted aniline derivative, and aluminum iodide or aluminum chloride were sequentially added. Add and stir. This mixture was heated and the results in Table 1 were obtained.

Comparative Example 1 The same procedure as in Example 1 was performed except that aluminum iodide was not used, and the yield of benzofuranol was 5%.
It was extremely low.

Examples 7 to 10 Using the same reactor as in Example 1, 16.49 (10 mmol) of monoether was added under a nitrogen gas atmosphere.
, N,N-dimethylaniline, a solvent, and aluminum iodide or aluminum chloride are sequentially added and stirred. This mixture was heated and the results in Table 2 were obtained.

Example 11 The inside of a stainless-lined autoclave equipped with a thermometer and a stirring device was placed under a nitrogen gas atmosphere, and 16.49 (100 mmol) of monoether, N,N-dimethylaninon, 1.07, Mesitylene 1007 and 0.5 g of aluminum iodide are added in sequence and stirred. When this mixture was heated at 200° C. for 2 hours, the yield of benzofuranol was 78%.

Example 12 Toluene 10 was substituted for mesitylene in Example 11.
The yield of benzofuranol was 78%.1 Patent applicant Otsuka Chemical Co., Ltd. Representative Patent attorney 1) Iwao Mura Procedural Amendment ( Voluntary) May 18, 1980 Commissioner of the Japan Patent Office Shima 1) Haruki Tono1, Indication of the case Patent Application No. 58745 of 19873, Relationship with the person making the amendment case Patent applicant Otsuka Chemicals Co., Ltd.4 , Agent 6, Number of declines increased by amendment 8, Contents of amendment Procedural amendment (0 phantom June 29, 1980 Commissioner of the Japan Patent Office Shima 1) Haruki Tono ■, Indication of the case 1982 patent Application No. 58745 2° Title of the invention 2, Process for producing 3-cyitrow 2,2-dimethy lehr-hydroxybenzofuran 3,
Relationship with the case of the person making the amendment Patent applicant Otsuka Chemical Co., Ltd. 4, Attorney 6, Number of inventions increased by the amendment Contents of the amendment 1 The statement “suitable” on page 7, line 9 of the specification It is corrected to say, "The solvent used is not particularly limited, but is suitable."

2. The phrase "aliphatic ether" on page 7, line 12 of the specification is corrected to "aliphatic ether, aromatic ketone, aliphatic ketone."

3. On page 8, line 5 of the specification, the phrase "ether etc." is replaced with "ether etc." and specific examples of aromatic or aliphatic ketones include hapenzophenone, acetophenone, p-hydroxyacetophenone, acetone, methyl in butyl ketone,
Cyclohexanone, etc.” is corrected.

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Claims (1)

[Claims] (1) Rearrangement and cyclization of ortho-metaloxyphenol by F5 and 8-dihydro. In order to obtain dimethyl-dimethyl-hydride-containing oxybenzofuran, alkaline chloride or aluminum chloride is used as a catalyst and the general formula (wherein R1 and R1 have 1 to 6 carbon atoms)
an alkyl group, a phenyl group, or R1 and R3 are combined to form an alkylene group having b to 70 carbon atoms, and Ha is hydrogen or an alkyl group having 1 to 8 carbon atoms. 2,3-sibaido-2,2-dimethyl- characterized by ξ using a complex of
Method for producing 7-hydroxybenzofuran. ■ Claim 1 uses one or more selected from aniline derivatives represented by the above general formula (1), aromatic hydrocarbons, aliphatic hydrocarbons, aromatic ethers, and aliphatic ethers as a solvent. Manufacturing method described. (2) The process according to claim 1, wherein the reaction is carried out at a temperature range of about 60 to 250°C.