JP2007246506A - Production method of cyclobutalene - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing cyclobutalene under conditions not generating corrosive products such as hot hydrogen chloride. <P>SOLUTION: The production method of cyclobutalene is characterized by that an aromatic compound having a methyl group having an ether bond or a hydroxyl group and having a substituted methyl group having a methyl group or at least one hydrogen atom at the ortho position is brought into contact with a catalyst which is prepared by causing at least one element selected from among the group 1, group 2, group 3, group 4, group 5, group 6, group 7, group 8, group 9, group 10, group 11, group 12, group 13, group 14, and group 15 of the periodic table to be supported by a carrier. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing arylcyclobutene (generally called cyclobutalene), which is an aromatic hydrocarbon having a cyclobutene ring.

  Cyclobutalene, especially benzocyclobutene, is an important intermediate for the production of monomers useful in the production of high performance polymers. Patent Document 1 describes the production of a polymer by treating biscyclobutalene. This polymer exhibits high electrical properties such as high thermal stability, solvent resistance, good mechanical properties and low dielectric constant, and is useful as a high-functional resin for use in the electronics industry.

  Conventionally, cyclobutalene has been produced by flash vacuum pyrolysis of an ortho-methyl-benzyl chloride derivative as shown in Non-Patent Document 1. For example, benzocyclobutene is synthesized from flash vacuum pyrolysis of α-chloro-ortho-xylene. This reaction is performed at a high temperature of 600 ° C. or higher. In Patent Document 2, benzocyclobutene is obtained by thermally decomposing an ortho-alkylhalomethyl aromatic compound in the presence of an inert solvent. In Patent Document 3, benzocyclobutene is obtained by steam pyrolysis.

  In these reactions, there is a problem that hydrogen chloride is generated because a chlorinated raw material is used. Moreover, in order to improve a yield, high temperature of 550 degreeC or more is required, and in order to obtain a high yield, about 700 degreeC high temperature is required. Thus, in these methods, high temperature hydrogen chloride is generated, and there is a problem of corrosion of equipment.

  On the other hand, as a method not using a halomethyl compound, a method using an acetoxylmethyl compound has been proposed in Patent Document 3, Non-Patent Document 2, and the like. However, since Examples are not shown in Patent Document 3, a specific method is described. Is unknown. However, even in this method not using a halomethyl compound, in order to increase the yield, a high temperature of 700 ° C. or higher is required, and there are many side reactions and the selectivity is low.

U.S. Pat. No. 4,540,763 Japanese Patent Publication No. 64-4493 JP-A-1-146830 Schiess et al., “Tetrahedron Letter” (UK), 1978, 46, p. 4569-4572 "American Chemical Society Preprints Division of Petroleum Chemistry" (USA), 1979, Vol. 24, No. 4, p. 1082-1086

  In view of these drawbacks of the prior art, a method for producing cyclobutalene under conditions that do not generate high-temperature hydrogen chloride is desired. The present invention has been made for the purpose of providing such a method.

As a result of diligent research, the present inventors have found that the above-mentioned problems can be solved by catalytic reaction of a specific aromatic compound using a metal-supported catalyst, and the present invention has been completed.
That is, the present invention relates to an aromatic compound having a methyl group having an ether bond or a hydroxyl group and having a methyl group or a substituted methyl group having at least one hydrogen in the ortho position. Group, Group 3, Group 4, Group 5, Group 6, Group 7, Group 8, Group 9, Group 10, Group 11, Group 12, Group 13, Group 14 and The present invention relates to a process for producing cyclobutalene, which comprises contacting a catalyst having at least one element selected from Group 15 supported on a carrier.

  By the method of the present invention, a cyclobutalene compound can be produced with good yield without generating high-temperature hydrogen chloride.

The present invention will be described in detail below.
The aromatic compound used as a starting material in the present invention is an aromatic compound having a methyl group having an ether bond or a hydroxyl group and having a methyl group or a substituted methyl group having at least one hydrogen in the ortho position. Here, the substituted methyl group having at least one hydrogen means a group in which one or two hydrogens of the methyl group are substituted with any atom or group, and particularly an alkyl group having 1 to 10 carbon atoms. An alkyl-substituted methyl group substituted with is preferred. Moreover, as an aromatic compound, the aromatic compound whose aromatic part is benzene, naphthalene, anthracene, or phenanthracene can be used.

As the aromatic compound, a compound represented by the following formula is particularly preferable.

In the above formula, R represents hydrogen or an alkyl group having 1 to 10 carbon atoms. Specific examples of the alkyl group having 1 to 10 carbon atoms include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group and decyl group.
R is preferably hydrogen or an alkyl group having 1 to 5 carbon atoms, particularly preferably hydrogen, a methyl group or an ethyl group.
In the above formula, R ′ represents hydrogen or an alkyl group having 1 to 10 carbon atoms, and two R ′ may be the same or different. R ′ is particularly preferably hydrogen, a methyl group or an ethyl group.
In the above formula, R ″ represents a group that is stable with respect to the reaction conditions. R ″ is not particularly limited as long as it is a group that is stable with respect to the reaction conditions, and examples thereof include a methyl group, a methoxy group, and a methoxycarbonyl group. Nitro group, chlorine, bromine or iodine. n is an integer of 0 to 4, preferably 0 or 1.

In the present invention, the aromatic compound is converted into Group 1, Group 2, Group 3, Group 4, Group 5, Group 6, Group 7, Group 8, Group 9, Group 10 of the Periodic Table. A cyclobutalene is produced by contacting with a catalyst formed by supporting at least one element selected from Group 11, Group 12, Group 12, Group 13, Group 14 and Group 15 on a carrier. is there.
1st group, 2nd group, 3rd group, 4th group, 5th group, 6th group, 7th group, 8th group, 9th group, 10th group, 11th group, 12th group, The element selected from Group 13, Group 14 and Group 15 is preferably sodium, potassium, magnesium, calcium, lanthanum, samarium, hafnium, vanadium, tin, chromium, manganese, iron, cobalt, nickel, copper , Zinc, ruthenium, rhodium, palladium, silver, indium, rhenium, iridium, platinum, bismuth, and more preferably lanthanum, iron, cobalt, ruthenium, palladium, iridium, and platinum. Moreover, these metals can be used as a main component in combination with a small amount of other metals.

  A known catalyst carrier can be used as the carrier used in the present invention. Examples thereof include silica, alumina, silica-alumina, zeolite, diatomaceous earth, silica-magnesia, silica-zirconia, magnesia, titania, zirconia, calcia, and composites thereof. Among these, the zeolite has no particular restriction on the crystal structure, and for example, synthetic zeolites such as ZSM-5, faujasite, erionite, offretite, mordenite, ferrierite, and natural zeolite can be used. The cation species of these zeolites may be any of protons, alkali metals, and alkaline earth metals. Of these, silica is particularly preferably used in the present invention.

A commercially available product can be used as the carrier, but the carrier has a surface area of 50 to 500 m ² / g, an average pore diameter of 50 to 500 angstroms, and a pore volume of 0.3 to 1.2 ml / g. Are preferably used. The shape of these carriers is not particularly limited, and powdered or molded products can be used. For example, powders, granules, tablet compression molded products, spherical or rod-shaped extruded products, and the like are preferably used.

1st group, 2nd group, 3rd group, 4th group, 5th group, 6th group, 7th group, 8th group, 9th group, 10th group, 11th group, 12th group, A method for supporting an element selected from Group 13, Group 14 and Group 15 on the carrier is not particularly limited, and a known method can be used. For example, it can be supported using various methods such as a precipitation method, an ion exchange method, an impregnation method, a deposition method, and a kneading method.
For example, to further illustrate the impregnation method, the periodic table Group 1, Group 2, Group 3, Group 4, Group 5, Group 6, Group 7, Group 8, Group 9, Group A source material containing an element selected from Group 10, Group 11, Group 12, Group 13, Group 14 and Group 15 is dissolved in an appropriate solvent, and this is immersed in a carrier, and if necessary, predetermined Then, after removing the solvent by a known method and drying, the catalyst is obtained by calcination as necessary. The drying atmosphere is not particularly limited and may be a vacuum, an inert atmosphere such as nitrogen, air, or a reducing gas such as hydrogen gas. The firing temperature is preferably 120 to 700 ° C, more preferably 300 to 500 ° C.

Periodic table used in preparing the catalyst Group 1, Group 2, Group 3, Group 4, Group 5, Group 7, Group 7, Group 8, Group 9, Group 10, Group The raw material containing an element selected from Group 11, Group 12, Group 13, Group 14 and Group 15 is not particularly limited, and usually salts, complex compounds, organometallic complexes of these elements, A hydroxide or the like is used.
Examples of the salt of the element include organic acid salts such as sulfate, nitrate, hydrochloride, perchlorate, carbonate, phosphate and acetate, acetylacetonate salt, and the like.
In addition, as the complex compound or organometallic complex of the element, in the case of lanthanum, for example, triscyclopentadienyl lanthanum, tris (2,2,6,6-tetramethyl-3,5-heptadionate) lanthanum, etc. Is used. In the case of hafnium, for example, bis (cyclopentadienyl) hafnium dichloride, bis (t-butylcyclopentadienyl) hafnium dichloride, bis (ethylcyclopentadienyl) hafnium dichloride, bis (pentamethylcyclopentadienyl) ) Hafnium dichloride, dimethylbis (t-butylcyclopentadienyl) hafnium, etc. are used. In the case of vanadium, for example, vanadocene dichloride, vanadocene, vanadyl acetylacetonate, biscyclopentadienyl vanadium carbonyl and the like are used. In the case of chromium, for example, chromium hexacarbonyl, benzene chromium tricarbonyl, pentamethylcyclopentadienyl chromium dicarbonyl dimer and the like can be used. In the case of manganese, for example, pentacarbonyl manganese bromide, biscyclopentadienyl manganese, cyclopentadienyl manganese tricarbonyl and the like can be used. In the case of iron, for example, sodium chlorophyll iron, monosodium ethylenediaminetetraacetate / iron (III), potassium ferricyanide, potassium ferrocyanide, ferrocene, cyclopentadienyl iron dicarbonyl dimer and the like can be used. In the case of cobalt, for example, biscyclopentadienyl cobalt and cobalt carbonyl can be used. In the case of nickel, for example, potassium tetracyanonickelate, biscyclopentadienyl nickel, bis (1,5-cyclooctadienyl) nickel, hexaamine nickel chloride and the like can be used. In the case of copper, for example, copper chlorophyllin potassium, copper chlorophyllin sodium, tetraammine copper sulfate and the like can be used. In the case of zinc, for example, ethylenediaminetetraacetic acid disodium zinc, tetraammine zinc carbonate, etc. can be used. In the case of rhenium, for example, cyclopentadienylrhenium tricarbonyl, rhenium pentacarbonyl chloride and the like can be used. In the case of iridium, for example, iridium carbonyl, chloro 1,5-cyclooctadiene iridium dimer, cyclooctadiene acetylacetonatoiridium, cyclopentadienyl cyclooctadiene iridium and the like can be used. In the case of palladium, for example, ammonium tetrachloropalladium (II), sodium tetrachloropalladium (II), potassium tetrachloropalladium (II), sodium hexachloropalladium (IV), sodium tetrabromopalladium (II) , Tetraamminepalladium (II) dichloride, bis (acetonitrile) palladium (II) dichloride, bis (benzonitrile) palladium (II) dichloride, dichloro (cyclooctadiene) palladium (II), dichlorobis (triphenylphosphine) palladium (II ) Etc. can be used. In the case of platinum, for example, ammonium tetrachloroplatinate (II), sodium tetrachloroplatinate (II), potassium tetrachloroplatinate (II), potassium hexachloroplatinate (IV), tetraammineplatinum (II) dichloride, dichlorobis (Triphenylphosphine) platinum (II), tetrakistriphenylphosphine platinum (0) and the like can be used. In the case of ruthenium, for example, potassium hexachlororuthenium (IV), sodium ruthenium (VI), ruthenium hexaammine (III) bromide, potassium tris (oxalate) ruthenium (III), dodecacarbonyltriruthenium (0), dichloro Tris (triphenylphosphine) ruthenium (II) or the like can be used. In the case of rhodium, for example, ammonium hexachlororhodium (III), hexaamminerhodium (III) trichloride, chlorotris (triphenylphosphine) rhodium (I), dichlorotetracarbonylnitrodium (I), dodecacarbonyl tetrarhodium ( 0) etc. can be used. In the case of silver, for example, 2,2,6,6-tetramethyl-3,5-heptadionate silver, trimethylphosphine (hexafluoroacetylacetonate) silver or the like can be used. In the case of tin, for example, hexafluoroacetylacetonate tin, di-n-butyltin bisacetylacetonate and the like can be used. In the case of indium, for example, cyclopentadienyl indium, tris (2,2,6,6-tetramethyl-3,5-heptanedionate) indium or the like can be used. In the case of bismuth, for example, tris (2,2,6,6-tetramethyl-3,5-heptadionate) bismuth, bismuth naphthenate, etc. can be used.

  1st group, 2nd group, 3rd group, 4th group, 5th group, 6th group, 7th group, 8th group, 9th group, 10th group, 11th group, 12th group, The amount of the element selected from Group 13, Group 14 and Group 15 on the carrier is preferably 0.001 to 10% by weight, more preferably 0.01 to 1% by weight, based on the weight of the carrier. It is. If the loading is less than 0.001% by weight, a substantial reaction rate cannot be obtained, and if it is more than 10% by weight, it is economically disadvantageous.

In the present invention, by reacting the aromatic compound in contact with the supported catalyst, a cyclobutene ring is formed by a reaction between a methyl group having an ether bond or a hydroxyl group and a hydrogen in the ortho-positioned methyl group or a substituted methyl group. To form cyclobutalene.
The reaction temperature is preferably 300 to 800 ° C, more preferably 400 to 750 ° C, and most preferably 450 to 700 ° C.
The reaction pressure is not particularly limited as long as it is equal to or lower than atmospheric pressure, but is preferably 6 Pa to 10 kPa, and particularly preferably 10 Pa to 5 kPa, in order to prevent condensation of the generated cyclobutalene compound.
The reaction can be carried out under an inert gas flow such as nitrogen, helium or argon. It can also be carried out in the presence of vaporized inert compounds such as benzene and substituted benzene.

  The reaction can be performed, for example, by circulating the vaporized raw material in a tubular reactor filled with a catalyst and heated to a predetermined temperature. The reaction tube material is not particularly limited as long as it is inert to the reactant and is stable under the reaction conditions. For example, quartz is used. It is also desirable for the tube shape to have a length: diameter ratio as large as practical. For example, a tubular reactor having a length: diameter ratio greater than 10: 1 is preferably employed. The aromatic compound as a raw material can be supplied to a reactor whose pressure is reduced to atmospheric pressure or lower by any method. It is preferable to vaporize the reaction agent before entering the reactor, and when it is carried out in the presence of an inert gas or a vaporized inert compound, it can be mixed with the raw material by any method. Preferably, they are mixed in advance when the raw material is vaporized and supplied to the reactor. The product that has passed through the catalyst is immediately cooled and recovered. The target product can be separated by any method such as distillation.

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

Example 1
12.5 mg of potassium chloroplatinate was dissolved in 10 ml of distilled water, immersed in 10 g of silica (Fuji Silysia Chemical Co., Ltd .: Q-10) as a carrier, and then the water was distilled off using an evaporator. The obtained solid was dried at 120 ° C. for 12 hours, calcined at 500 ° C. for 3 hours in a nitrogen atmosphere, and further calcined at 500 ° C. for 3 hours in a hydrogen stream to obtain a catalyst having platinum supported on silica. It was. The amount of platinum supported on the platinum-supported catalyst was 0.05% by weight with respect to silica.
Next, using a quartz tube pyrolysis reactor having an inner diameter of 10 mm and a length of 60 cm, 1 g of the prepared catalyst was charged in the center of the reactor. It fixed with quartz glass wool so that a catalyst might not move, and it put into the electric furnace and heated to 450 degreeC average temperature. 200 mg of 2-methylbenzyl alcohol heated and vaporized was supplied over 1 hour to a reactor filled with the catalyst under reduced pressure and a pressure of 130 Pa. The reactor effluent gas was cooled and condensed with liquid nitrogen.
The collected effluent was analyzed for organic phase by gas chromatography using tetradecane as an internal standard. As a result, 49% of 2-methylbenzyl alcohol reacted, of which 32% became benzocyclobutene. Therefore, the yield from 2-methylbenzyl alcohol to benzocyclobutene was 15.7%.

(Example 2)
2-methylbenzyl was reacted under the same reaction conditions as in Example 1 except that the catalyst support in Example 1 was changed from silica to alumina (manufactured by JGC Chemical Co., Ltd.). When alcohol was reacted, 60% of 2-methylbenzyl alcohol was reacted, and 25% of it was converted to benzocyclobutene. Therefore, the yield from 2-methylbenzyl alcohol to benzocyclobutene was 15%.

(Example 3)
The reaction of 2-methylbenzyl alcohol was carried out under the same reaction conditions as in Example 1 except that the supported metal was changed from platinum to palladium in Example 1 (palladium chloride was used as the metal salt, and the palladium supported amount was 0.05% by weight). As a result, 32% of 2-methylbenzyl alcohol was reacted, and 26% of it was converted to benzocyclobutene. Therefore, the yield from 2-methylbenzyl alcohol to benzocyclobutene was 8.3%.

Example 4
When 2-methylbenzyl alcohol was reacted under the same reaction conditions as in Example 1 except that the reaction temperature was changed to 650 ° C. in Example 1, 95% of 2-methylbenzyl alcohol reacted. 64% became benzocyclobutene. Therefore, the yield from 2-methylbenzyl alcohol to benzocyclobutene was 61%.

(Example 5)
Except that the reaction temperature was changed to 650 ° C. in Example 3, 2-methylbenzyl alcohol was reacted under the same reaction conditions as in Example 3. As a result, 95% of 2-methylbenzyl alcohol reacted. 54% became benzocyclobutene. Therefore, the yield from 2-methylbenzyl alcohol to benzocyclobutene was 51%.

(Example 6)
The reaction of 2-methylbenzyl alcohol was carried out under the same reaction conditions as in Example 1 except that the supported metal was changed from platinum to rhodium in Example 1 (rhodium nitrate was used as the metal salt, and the supported amount of rhodium was 0.05% by weight). As a result, 48% of 2-methylbenzyl alcohol was reacted, and 6% of it was converted to benzocyclobutene. Therefore, the yield from 2-methylbenzyl alcohol to benzocyclobutene was 2.9%.

(Example 7)
In Example 1, except that the supported metal was changed from platinum to iridium (iridium acetylacetonate was used as the metal salt, the iridium supported amount was 0.05% by weight) under the same reaction conditions as in Example 1, 2-methylbenzyl alcohol As a result of the reaction, 30% of 2-methylbenzyl alcohol was reacted, and 20% of it was converted to benzocyclobutene. Therefore, the yield from 2-methylbenzyl alcohol to benzocyclobutene was 6%.

(Example 8)
The reaction of 2-methylbenzyl alcohol was carried out under the same reaction conditions as in Example 1, except that the supported metal was changed from platinum to ruthenium in Example 1 (ruthenium nitrate was used as the metal salt, and the amount of ruthenium supported was 0.05% by weight). As a result, 31% of 2-methylbenzyl alcohol reacted, 22% of which was converted to benzocyclobutene. Therefore, the yield from 2-methylbenzyl alcohol to benzocyclobutene was 6.8%.

Example 9
In Example 1, 2-methylbenzyl was used under the same reaction conditions as in Example 1 except that the supported metal was changed from platinum to manganese (manganese (II) acetate was used as the metal salt and the manganese loading was 0.05% by weight). When alcohol was reacted, 30% of 2-methylbenzyl alcohol was reacted, and 10% of it was converted to benzocyclobutene. Therefore, the yield from 2-methylbenzyl alcohol to benzocyclobutene was 3%.

(Example 10)
The reaction of 2-methylbenzyl alcohol was carried out under the same reaction conditions as in Example 1 except that the supported metal in Example 1 was changed from platinum to rhenium (rhenium chloride was used as the metal salt, and the amount of rhenium supported was 0.05% by weight). As a result, 40% of 2-methylbenzyl alcohol was reacted, and 9% of it was converted to benzocyclobutene. Therefore, the yield from 2-methylbenzyl alcohol to benzocyclobutene was 3.6%.

(Example 11)
Example 1 except that the supported metal in Example 1 is changed from platinum to silver (silver nitrate (I) is used as a metal salt, the amount of supported silver is 0.05% by weight), and the baking is not performed in a hydrogen stream at 500 ° C. for 3 hours. When 2-methylbenzyl alcohol was reacted under the same reaction conditions as 1, 40% of 2-methylbenzyl alcohol was reacted, and 10% of that was benzocyclobutene. Therefore, the yield from 2-methylbenzyl alcohol to benzocyclobutene was 4%.

(Example 12)
In Example 1, the supported metal was changed from platinum to nickel (nickel (II) acetate was used as the metal salt, the nickel supported amount was 0.05% by weight), and it was carried out except that firing was not performed at 500 ° C. for 3 hours in a hydrogen stream. When 2-methylbenzyl alcohol was reacted under the same reaction conditions as in Example 1, 40% of 2-methylbenzyl alcohol was reacted, and 15% of that was benzocyclobutene. Therefore, the yield from 2-methylbenzyl alcohol to benzocyclobutene was 6%.

(Example 13)
In Example 1, the supported metal was changed from platinum to indium (indium (III) acetate was used as a metal salt, the amount of indium supported was 0.05% by weight), and it was carried out except that firing was not performed at 500 ° C. for 3 hours in a hydrogen stream. When 2-methylbenzyl alcohol was reacted under the same reaction conditions as in Example 1, 30% of 2-methylbenzyl alcohol reacted, of which 7% became benzocyclobutene. Therefore, the yield from 2-methylbenzyl alcohol to benzocyclobutene was 2.1%.

(Example 14)
In Example 1, the supported metal was changed from platinum to copper (copper (II) acetate was used as a metal salt, the amount of supported copper was 0.05% by weight), and it was carried out except that firing was not performed at 500 ° C. for 3 hours in a hydrogen stream. When 2-methylbenzyl alcohol was reacted under the same reaction conditions as in Example 1, 45% of 2-methylbenzyl alcohol reacted, of which 12% became benzocyclobutene. Therefore, the yield from 2-methylbenzyl alcohol to benzocyclobutene was 5.4%.

(Example 15)
In Example 1, the supported metal was changed from platinum to cobalt (cobalt (II) acetate was used as the metal salt, the cobalt supported amount was 0.05% by weight), and it was carried out except that firing was not performed at 500 ° C. for 3 hours in a hydrogen stream. When 2-methylbenzyl alcohol was reacted under the same reaction conditions as in Example 1, 40% of 2-methylbenzyl alcohol was reacted, and 15% of that was benzocyclobutene. Therefore, the yield from 2-methylbenzyl alcohol to benzocyclobutene was 6%.

(Example 16)
Example 1 is different from Example 1 except that the supported metal is changed from platinum to zinc (zinc acetate is used as the metal salt, the zinc supported amount is 0.05% by weight), and the firing is not performed at 500 ° C. for 3 hours in a hydrogen stream. When 2-methylbenzyl alcohol was reacted under the same reaction conditions, 50% of 2-methylbenzyl alcohol was reacted, and 10% of that was benzocyclobutene. Therefore, the yield from 2-methylbenzyl alcohol to benzocyclobutene was 5%.

(Example 17)
In Example 1, the supported metal was changed from platinum to iron (iron (III) nitrate was used as a metal salt, the amount of iron supported was 0.05% by weight), and it was carried out except that firing was not performed at 500 ° C. for 3 hours in a hydrogen stream. When 2-methylbenzyl alcohol was reacted under the same reaction conditions as in Example 1, 30% of 2-methylbenzyl alcohol reacted, of which 10% became benzocyclobutene. Therefore, the yield from 2-methylbenzyl alcohol to benzocyclobutene was 3%.

(Example 18)
In Example 1, except that the supported metal is changed from platinum to tin (using metal chloride (II) as the metal salt, the amount of tin supported is 0.05% by weight), and no firing is performed in a hydrogen stream at 500 ° C. for 3 hours. When 2-methylbenzyl alcohol was reacted under the same reaction conditions as in Example 1, 20% of 2-methylbenzyl alcohol reacted, of which 5% became benzocyclobutene. Therefore, the yield from 2-methylbenzyl alcohol to benzocyclobutene was 1%.

Example 19
In Example 1, the supported metal was changed from platinum to chromium (chromium (III) acetate was used as a metal salt, the amount of chromium supported was 0.05% by weight), and it was carried out except that firing was not performed at 500 ° C. for 3 hours in a hydrogen stream. When 2-methylbenzyl alcohol was reacted under the same reaction conditions as in Example 1, 25% of 2-methylbenzyl alcohol reacted, of which 10% became benzocyclobutene. Therefore, the yield from 2-methylbenzyl alcohol to benzocyclobutene was 2.5%.

(Example 20)
In Example 1, the supported metal was changed from platinum to bismuth (bismuth (III) acetate was used as the metal salt, the bismuth supported amount was 0.05% by weight), and it was carried out except that firing was not performed at 500 ° C. for 3 hours in a hydrogen stream. When 2-methylbenzyl alcohol was reacted under the same reaction conditions as in Example 1, 50% of 2-methylbenzyl alcohol reacted, of which 10% became benzocyclobutene. Therefore, the yield from 2-methylbenzyl alcohol to benzocyclobutene was 5%.

(Example 21)
In Example 1, the supported metal was changed from platinum to lanthanum (using lanthanum (III) acetate as the metal salt, the lanthanum supported amount was 0.05% by weight), and it was carried out except that firing was not performed at 500 ° C. for 3 hours in a hydrogen stream. When 2-methylbenzyl alcohol was reacted under the same reaction conditions as in Example 1, 45% of 2-methylbenzyl alcohol reacted, of which 38% became benzocyclobutene. Therefore, the yield from 2-methylbenzyl alcohol to benzocyclobutene was 17%.

(Example 22)
In Example 1, the supported metal was changed from platinum to hafnium (hafnium (IV) chloride was used as the metal salt, the hafnium supported amount was 0.05% by weight), and it was carried out except that firing was not performed for 3 hours at 500 ° C. in a hydrogen stream. When 2-methylbenzyl alcohol was reacted under the same reaction conditions as in Example 1, 20% of 2-methylbenzyl alcohol reacted, 15% of which became benzocyclobutene. Therefore, the yield from 2-methylbenzyl alcohol to benzocyclobutene was 3%.

(Example 23)
Example 1 except that the supported metal is changed from platinum to vanadium in Example 1 (vanadium pentoxide is used as the metal salt, the vanadium supported amount is 0.05% by weight), and firing is performed at 500 ° C. for 3 hours in a hydrogen stream. When 2-methylbenzyl alcohol was reacted under the same reaction conditions as in Example 1, 70% of 2-methylbenzyl alcohol was reacted, and 10% of that was benzocyclobutene. Therefore, the yield from 2-methylbenzyl alcohol to benzocyclobutene was 7%.

(Example 24)
Example 1 is different from Example 1 except that the supported metal is changed from platinum to sodium (sodium chloride is used as the metal salt, the amount of sodium supported is 0.05% by weight), and the firing is not performed at 500 ° C. for 3 hours in a hydrogen stream. When 2-methylbenzyl alcohol was reacted under the same reaction conditions, 30% of 2-methylbenzyl alcohol was reacted, and 10% of that was benzocyclobutene. Therefore, the yield from 2-methylbenzyl alcohol to benzocyclobutene was 3%.

(Example 25)
Example 1 is different from Example 1 except that the supported metal is changed from platinum to potassium (potassium chloride is used as the metal salt, the amount of potassium supported is 0.05% by weight), and the baking is not performed in a hydrogen stream at 500 ° C. for 3 hours. When 2-methylbenzyl alcohol was reacted under the same reaction conditions, 20% of 2-methylbenzyl alcohol was reacted, and 10% of this was benzocyclobutene. Therefore, the yield from 2-methylbenzyl alcohol to benzocyclobutene was 2%.

(Example 26)
Example 1 is different from Example 1 except that the supported metal is changed from platinum to magnesium (magnesium chloride is used as a metal salt, the amount of magnesium supported is 0.05% by weight), and the firing is not performed at 500 ° C. for 3 hours in a hydrogen stream. When 2-methylbenzyl alcohol was reacted under the same reaction conditions, 10% of 2-methylbenzyl alcohol was reacted, and 15% of that was benzocyclobutene. Therefore, the yield from 2-methylbenzyl alcohol to benzocyclobutene was 1.5%.

(Example 27)
Example 1 is different from Example 1 except that the supported metal is changed from platinum to calcium in Example 1 (calcium chloride is used as a metal salt, the amount of calcium supported is 0.05% by weight), and firing is not performed at 500 ° C. for 3 hours in a hydrogen stream. When 2-methylbenzyl alcohol was reacted under the same reaction conditions, 30% of 2-methylbenzyl alcohol was reacted, and 10% of that was benzocyclobutene. Therefore, the yield from 2-methylbenzyl alcohol to benzocyclobutene was 3%.

(Example 28)
In Example 1, the supported metal is changed from platinum to samarium (samarium chloride is used as a metal salt, the amount of samarium supported is 0.05% by weight), and the example 1 is the same as in Example 1 except that firing is not performed at 500 ° C. for 3 hours in a hydrogen stream. When 2-methylbenzyl alcohol was reacted under the same reaction conditions, 50% of 2-methylbenzyl alcohol was reacted, and 20% of that was benzocyclobutene. Therefore, the yield from 2-methylbenzyl alcohol to benzocyclobutene was 10%.

(Example 29)
When 2- (methoxymethyl) toluene was reacted under the same reaction conditions as in Example 1 except that the reaction reagent was changed from 2-methylbenzyl alcohol to 2- (methoxymethyl) toluene in Example 1, 27% Of 2- (methoxymethyl) toluene reacted, 11% of which became benzocyclobutene. Therefore, the yield from 2- (methoxymethyl) toluene to benzocyclobutene was 3%.

(Example 30)
When 2- (methoxymethyl) toluene was reacted under the same reaction conditions as in Example 29 except that the reaction temperature was changed from 450 ° C. to 650 ° C. in Example 29, 40% of 2- (methoxymethyl) toluene was obtained. Of which 15% became benzocyclobutene. Therefore, the yield from 2- (methoxymethyl) toluene to benzocyclobutene was 6%.

(Comparative Example 1)
In place of the catalyst used in Example 1, 1 g of quartz beads was charged into a reaction tube and reacted with 2-methylbenzyl alcohol under the same reaction conditions as in Example 1. As a result, 6% of 2-methylbenzyl alcohol was obtained. Although it reacted, benzocyclobutene was not obtained.

(Comparative Example 2)
In place of the catalyst used in Example 4, 1 g of quartz beads was charged into a reaction tube, and 2-methylbenzyl alcohol was reacted under the same reaction conditions as in Example 4. As a result, 10% of 2-methylbenzyl alcohol was Although it reacted, benzocyclobutene was not obtained.

(Comparative Example 3)
In place of the catalyst used in Example 29, 1 g of quartz beads was charged into a reaction tube, and 2- (methoxymethyl) toluene was reacted under the same reaction conditions as in Example 29. As a result, 2% 2-methylbenzyl was obtained. Alcohol reacted but benzocyclobutene was not obtained.

(Comparative Example 4)
In place of the catalyst used in Example 30, 1 g of quartz beads were charged into a reaction tube, and 2- (methoxymethyl) toluene was reacted under the same reaction conditions as in Example 30. As a result, 4% of 2-methylbenzyl was obtained. Alcohol reacted but benzocyclobutene was not obtained.

Claims (6)

  An aromatic compound having a methyl group having an ether bond or a hydroxyl group and having a methyl group or a substituted methyl group having at least one hydrogen in the ortho position is selected from Group 1, Group 2, Group 3 of the periodic table, Selected from Group 4, Group 5, Group 6, Group 7, Group 8, Group 9, Group 10, Group 11, Group 12, Group 13, Group 14, Group 15 and Group 15 A method for producing cyclobutalene, comprising contacting a catalyst having at least one element supported on a carrier. The method according to claim 1, wherein the aromatic compound is a compound represented by the following formula.

Wherein R represents hydrogen or an alkyl group having 1 to 10 carbon atoms, R ′ represents hydrogen or an alkyl group having 1 to 10 carbon atoms, and two R ′ may be the same or different, and R ″ Represents a group that is stable to the reaction conditions, and n represents an integer of 0 to 4.)   The production method according to claim 2, wherein R in the formula is hydrogen, a methyl group or an ethyl group.   The production method according to claim 2, wherein R ″ in the formula is a methyl group, a methoxy group, a methoxycarbonyl group, a nitro group, chlorine, bromine or iodine.   The production method according to claim 1, wherein the support is silica.   The production method according to claim 1, wherein the contact is performed under a reaction condition of 300 ° C. to 800 ° C. under atmospheric pressure.