KR870001162B1 - Preparation process of cyclobutene-substituted aromatic hydrocarbons - Google Patents

Abstract

butene ring is described. Thus, 50g methyl 3-(chloromethyl) -4- methyl benzoate in 200 ml o-xylene is added into a furnace, whose temp. is 730≰C and pressure 25 mmHg, for1Wn90i After cooling, the mixt. contg. o-xylene and acetone isdistillated by Vigreaux to give 15.5g methyl 3.4-cyclo-butabenzoate at 61≰C and 23g methyl 3- (chloromethyl)-4-methyl-benzoate.

Description

Process for preparing cyclobutene-substituted aromatic hydrocarbons

The present invention relates to a method for producing an aromatic hydrocarbon in which a cyclobutene ring is fused.

Aromatic hydrocarbons to which the cyclobutene ring is fused are useful for preparing monomers useful for producing high performance polymers. Such high performance polymers are useful as films, molding compositions, adhesives, and for the production of composite materials.

There are two main problems in the preparation of aromatic hydrocarbons in which cyclobutene rings are fused. The first problem is that this synthesis involves a complex multistep sequence. Moreover, in some methods the yield of the desired product is low.

There is a need for a process for preparing cyclobutene-substituted aromatic hydrocarbons that is simple and can yield hydrocarbons in high yield.

The present invention dissolves ortho-alkyl halomethyl aromatic hydrocarbons in an inert solvent, and then thermally decomposes the ortho-alkyl halomethyl aromatic hydrocarbon solution in an inert solvent under conditions in which ortho-alkyl and halomethyl substituents form a cyclobutene ring. It relates to a method for producing an aromatic hydrocarbon in which a cyclobutene ring is fused to an aromatic hydrocarbon, characterized by producing an aromatic hydrocarbon in which a butene ring is fused. The structural formula of the ortho-alkyl group is (R ′) ₂ —CH— wherein R ′ is independently at each occurrence hydrogen or C _1-20 alkyl, preferably hydrogen or C _1-3 alkyl, most preferably hydrogen Is).

The present invention provides a one step process for the preparation of cyclobutene-substituted aromatic hydrocarbons in which the hydrocarbons are produced in high yield.

Starting materials in this process include aromatic hydrocarbons in which the (R ′) ₂ —CH—alkyl group and the halomethyl group are at ortho position to each other. Preferred aromatic hydrocarbons include benzene, naphthalene, phenanthracene, anthracene, biphenyl, binaphthyl or diarylalkanes. More preferred aromatic hydrocarbons include benzene, naphthalene, biphenyl, binaphthyl or diphenylalkane. Most preferred aromatic hydrocarbons are benzene.

The R 'substituent in the (R') _2- CH- group is preferably hydrogen or C _1-3 alkyl, most preferably hydrogen. Halomethyl hydrocarbon is preferably bromomethyl or chloromethyl.

Aromatic hydrocarbons may be further substituted with one or more of the following substituents: carbonyloxyhydrocarbyl, oxycarbonylhydrocarbyl, carboxyamide, carboxy, carbonylhalo, cyano, nitro, hydroxy, hydrocarbyloxy, or Halogi. Preference is given to substituting aromatic hydrocarbons with one or more of these substituents. Preferred substituents are carbonyloxyhydrocarbyl, oxycarbonylhydrocarbyl, carboxamide, carboxy, carbonylhalo, nitro or hydrocarbyloxy and the like. More preferred substituents are carbonyloxyhydrocarbyl, oxycarbonylhydrocarbyl, carboxamide or oxyhydrocarbyl and the like. More preferred substituents are carbonyloxyalkyl hydrocarbons, with carbonyloxymethyl being most preferred.

In one preferred embodiment wherein the aromatic hydrocarbon is benzene, the starting materials correspond to the following general formula.

Where

R ¹ at each occurrence is independently hydrogen or C _1-20 alkyl;

R ² in each occurrence is independently carbonyloxyhydrocarbyl, oxycarbonylhydrocarbyl, carboxamide, carboxy, carbonylhalo, cyano, nitro, hydroxy, hydrocarbyloxy or halo;

X is chloro or bromo;

a is an integer from 0 to 4.

Examples of preferred starting reactants are as follows:

Ortho-methylchloromethylbenzene, ortho-ethylchloromethylbenzene, ortho-propylchloromethylbenzene, ortho-butylchloromethylbenzene, ortho-pentylchloromethylbenzene, ortho-hexylchloromethylbenzene, 3- or 4-methoxy ortho -Methylchloromethylbenzene, 3- or 4-methoxy ortho-ethylchloromethylbenzene, 3- or 4-methoxy ortho-propylchloromethylbenzene, 3- or 4-methoxy ortho-butylchloromethylbenzene, 3- Or 4-ethoxy ortho-methylchloromethylbenzene, 3- or 4-ethoxy ortho-ethylchloromethylbenzene, 3- or 4-ethoxy ortho-propylchloromethylbenzene, 3- or 4-ethoxy ortho-butyl Chloromethylbenzene, 3- or 4-propoxy ortho-methylchloromethylbenzene, 3- or 4-propoxy ortho-ethylchloromethylbenzene, 3- or 4-propoxy ortho-propylchloromethylbenzene, 3- or 4 Propoxy ortho-butylchloromethylbenzene, 3- or 4-butoxy Leto-methylchloromethylbenzene, 3- or 4-butoxy ortho-ethylchloromethylbenzene, 3- or 4-butoxy ortho-propylchloromethylbenzene, 3- or 4-butoxy ortho-butylchloromethylbenzene, 3 Or 4-pentoxy ortho-methylchloromethylbenzene, 3- or 4-pentoxy ortho-ethylchloromethylbenzene, 3- or 4-pentoxy ortho-propylchloromethylbenzene, 3- or 4-hexoxy ortho- Methylchloromethylbenzene, 3- or 4-hexoxy ortho-ethylchloromethylbenzene, 3- or 4-hexoxy ortho-propylchloromethylbenzene, 3- or 4-hexoxy ortho-butylchloromethylbenzene, methyl 3, 4-ortho-methylchloromethylbenzoate, methyl 3,4-ortho-ethylchloromethylbenzoate, methyl 3,4-ortho-propylchloromethylbenzoate, methyl 3,4-ortho-butylchloromethylbenzoate, ethyl 3,4-Ortho-methylchloromethylbenzoate, ethyl 3,4-ortho-ethylchloromethylbenzoate , Ethyl 3,4-ortho-propylchloromethylbenzoate, ethyl 3,4-ortho-butylchloromethylbenzoate, propyl 3,4-ortho-methylchloromethylbenzoate, propyl 3,4-ortho-ethylchloromethyl Benzoate, propyl 3,4-ortho-propylchloromethylbenzoate, propyl 3,4-ortho-butylchloromethylbenzoate, butyl 3,4-ortho-methylchloromethylbenzoate, butyl 3,4-ortho-ethyl Chloromethylbenzoate, butyl 3,4-ortho-propylchloromethylbenzoate, butyl 3,4-ortho-butylchloromethylbenzoate, pentyl 3,4-ortho-methylchloromethylbenzoate, pentyl 3,4-ortho -Ethylchloromethylbenzoate, pentyl 3,4-ortho-propylchloromethylbenzoate, pentyl 3,4-ortho-butylchloromethylbenzoate, hexyl 3,4-ortho-methylchloromethylbenzoate, hexyl 3,4 Ortho-ethylchloromethylbenzoate, hexyl 3,4-ortho-pro Philchloromethylbenzoate, hexyl 3,4-ortho-butylchloromethylbenzoate, benzyl 3,4-ortho-methylchloromethylbenzoate, benzyl 3,4-ortho-ethylchloromethylbenzoate, benzyl 3,4- Ortho-propylchloromethylbenzoate, benzyl 3,4-ortho-butylchloromethylbenzoate, phenyl 3,4-ortho-methylchloromethylbenzoate, phenyl 3,4-ortho-ethylchloromethylbenzoate, phenyl 3, 4-ortho-propylchloromethylbenzoate and phenyl 3,4-ortho-butylchloromethylbenzoate.

In the preferred starting reactants, the butyl group is selected from n-, i- or secondary butyl groups, but tertiary butyl groups are not selected.

In one even more preferred embodiment, the starting material is methyl 3,4-ortho-methylchloromethylbenzoate.

The product produced by the method of the present invention is an aromatic hydrocarbon having a cyclobutene ring fused to one of the rings of the aromatic hydrocarbon. Preferred aromatic hydrocarbons are the aromatic hydrocarbons described previously. The product may be substituted as previously described.

In one preferred embodiment wherein the aromatic hydrocarbon is benzene, the product generally corresponds to the following general formula.

Where

R ¹ , R ² and a are as defined above.

Among the preferred types of aromatic hydrocarbons in which a cyclobutene ring is fused, cyclobutabenzene (bicyclo (4,2,0) octa-1,3,5,7-tetraene) 1-alkyl-cyclobutabenzene, hydrocarbylcyclobutabenzo Eights, hydrocarbyl 1-alkylcyclobutabenzoate, hydrocarboxy cyclobutabenzene, hydrocarboxy 1-alkylcyclobutabenzene, cyclobutabenzamide, 1-alkylcyclobutabenzamide and the like. Even more preferred types include alkylcyclobutabenzoate, cyclobutabenzamide and alkoxy cyclobutabenzene and the like.

Some preferred examples of the aromatic hydrocarbons in which the cyclobutene ring is fused include methylcyclobutabenzene, ethylcyclobutabenzene, propylcyclobutabenzene, butylcyclobutabenzene, pentylcyclobutabenzene, hexylcyclobutabenzene, benzylcyclobutabenzene, and phenylcyclo Butabenzene, methyl cyclobutabenzoate, ethyl cyclobutabenzoate, propyl cyclobutabenzoate, butyl cyclobutabenzoate, pentyl cyclobutabenzoate, hexyl cyclobutabenzoate, benzyl cyclobutabenzoate, phenyl cyclobutabenzoate , Methoxycyclobutabenzene, ethoxycyclobutabenzene, propoxycyclobutabenzene, butoxycyclobutabenzene, pentoxycyclobutabenzene, hexoxycyclobutabenzene, benzoxycyclobutabenzene, phenoxycyclobutabenzene, N -Methylcyclobutabenzamide, N-ethylcyclobutabenzamide, N-propylcyclo Butabenzamide, N-butylcyclobutabenzamide, N-pentylcyclobutabenzamide, N-hexylcyclobutabenzamide, N-benzylcyclobutabenzamide, N-phenylcyclobutabenzamide and the like.

More preferable examples of the aromatic hydrocarbon in which the cyclobutene ring is fused are methyl cyclobutabenzoate, ethyl cyclobutabenzoate, propyl cyclobutabenzoate, pentyl cyclobutabenzoate and hexyl cyclobutabenzoate.

In one of the most preferred embodiments, the aromatic hydrocarbon to which the cyclobutene ring is fused is methyl cyclobutabenzoate and the like.

Hydrocarbyl herein refers to an organic residue containing a carbon atom and an oxygen atom. The term hydrocarbyl includes the following organic residues:

Alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, aryl, aliphatic and alicyclic aralkyl and alkaryl. Aliphatic herein refers to straight- and branched-chain and saturated and unsaturated hydrocarbon chains, ie alkyl, alkenyl or alkynyl and the like. Alicyclic in this context refers to saturated and unsaturated cyclic hydrocarbons, ie cycloalkenyl and cycloalkyl. Aryl herein refers to two aryl groups crosslinked with biaryl, biphenylyl, phenyl, naphthyl, phenanthranyl, anthranyl and alkylene groups. Alkaryl herein refers to alkyl-, alkenyl- or alkynyl-substituted aryl substituents, where aryl is as defined above. As used herein, aralkyl means an alkyl, alkenyl or alkynyl group substituted with an aryl group, where aryl is as defined above.

C _1-20 alkyl is linear and branched methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, Octadecyl, nonadecyl and eicosyl groups.

Cycloalkyl refers to an alkyl group containing one, two, three or more cyclic rings. Cycloalkenyl refers to mono-, di- and polycyclic groups having one or more double bonds. Cycloalkenyl also refers to a cycloalkenyl group in which two or more double bonds are present.

에 상응하는 치환체를 포함한다.Hydrocarbonylcarbonyloxirane refers to a substituent in which a hydrocarbyl residue is bonded to a carbonyl moiety and a carbonyl residue is bonded to an oxygen atom.

It includes a substituent corresponding to.

에 상응하는 치환체를 포함한다.In the present specification, hydrocarbylcarbonyl refers to a substituent in which a hydrocarbyl residue is bonded to a carbonyl moiety, and a general formula

It includes a substituent corresponding to.

에 상응하는 치환체를 포함한다.In the present specification, the hydrocarbyloxycarbonyl means a substituent in which a hydrocarbyl residue is bonded to an oxygen atom and the oxygen atom is bonded to a carbonyl residue.

It includes a substituent corresponding to.

(여기서, R²는 하이드로카빌 잔기이다)에 상응하는 치환체를 의미한다.Carboxamide is a general formula

(Wherein R ² is a hydrocarbyl residue).

(여기서, X는 할로겐이다)에 상응하는 치환체를 말한다.Carbonylhalolan General Formula

(Wherein X is a halogen).

에 상응하는 치환체를 의미한다.In the present specification, carboxy is a general formula

It means a substituent corresponding to.

Hydrocarbyloxy herein refers to a substituent corresponding to the general formula R ² -O-, wherein R ² is a hydrocarbyl residue.

In the process of the present invention, ortho-alkyl halomethyl aromatic hydrocarbons are dissolved in an inert solvent and then pyrolyzed to form a cyclobutene ring. Dissolving the aromatic hydrocarbon in a suitable solvent is important to the present invention because it allows the aromatic hydrocarbon fused with the cyclobutene ring to be produced in high yield.

Generally suitable solvents dissolve ortho-alkyl halomethyl aromatic hydrocarbons and are stable solvents under pyrolysis conditions. Preferred solvents include benzene, substituted benzene, biphenyl or substituted biphenyl. Preferred solvents are benzene, toluene, xylene, chlorobenzene, nitrobenzene, alkylbenzoate, phenylacetate or diphenylacetate and the like. The most preferred solvent is xylene.

In general, the ratio of solvent to the starting material ortho-alkyl halomethyl aromatic hydrocarbon is the ratio at which the starting material is dissolved and the product is produced in an acceptable yield. It is preferred that the ratio of solvent to starting material is at least 2: 1. The preferred ratio of solvent to starting material is 2: 1 to 10: 1, more preferably 3: 1 to 4: 1.

During pyrolysis, the starting material dissolved in the solvent is exposed to the temperature at which ortho-alkyl halomethyl aromatic hydrocarbons release hydrogen halide to form a cyclobutene ring. Suitable temperature is the temperature at which the above process occurs. Preferable temperature is 550 degreeC or more. More preferable temperature is 550 degreeC-750 degreeC, and most preferable temperature is 700 degreeC-750 degreeC.

Pyrolysis can occur at a pressure at which cyclobutene ring fused aromatic hydrocarbons are produced in good yield. Preferred pressures are 760 mm to 10 mm Hg (101.3 to 1.3 kPa). More preferred pressures are 25 mm to 75 mm Hg (3.3 to 10.0 kPa) and most preferred pressures are 25 mm to 35 mm Hg (3.3 to 4.7 kPa).

In one preferred embodiment, pyrolysis occurs by passing an ortho alkyl halomethyl aromatic hydrocarbon solution through a heat tube reactor at the pyrolysis temperature. In this embodiment, it is preferable to fill the heat pipe with the filling material. Fillers which are inert to the reactants and stable to the reaction conditions are suitable, for example, quartz chips and stainless steel helices.

The product may be recovered by distillation of the material after pyrolysis. In embodiments using a low boiling solvent, the solvent is from the first cut of the distillate, while the product is from the second cut. The starting material typically remains as a residual material in the distillation port and can then be recycled. When using a high boiling solvent such as biphenyl, substituted biphenyl or diphenyl acetate, the product is distilled off and the starting material remaining in the solvent is recycled.

Generally, in this process, aromatic hydrocarbons to which the cyclobutene ring is fused are produced in a yield of about 40%, and in a more preferred embodiment the yield is about 50%.

The following examples are merely illustrative and do not limit the scope of the claims or the scope of the invention.

Example 1

Pyrolysis of Methyl-3- (chloromethyl) -4-methylbenzoate

의 아세톤으로 열분해관을 세척한다. 아세톤용액을 냉각트랩에 모아진 오르토-크실렌용액과 혼합한다. 아세톤과 오르토-크실렌을 정상압력하에서 16in, 비그룩스칼럼(Vigreaux Column)으로 증류시킨다. 대부분의 오르토-크실렌이 증류될 때, 시스템을 0.5mmHg(67Pa)로 하고, 순수한 메틸 3,4-시클로부타벤조에이트 15.5g을 61℃에서 모은다. 증류포트에 남아있는 잔류물은 메틸 3-(클로로메틸)-4-메틸벤조에이트(23g)이다.The experimental apparatus is a quartz tube filled with quartz chips. The central part of the coffin is placed in the furnace. The 250 mm part of the furnace tube becomes the preheating zone, and the temperature in the middle of the preheating zone is 250 ° C to 300 ° C. At the top of the tube is an addition funnel. At the bottom of the tube is attached a device and a cooling trap for vacuuming the tube. Methyl 3- (chloromethyl) -4-methylbenzoate (50 g) is dissolved in 200 g of ortho xylene and placed in an addition funnel. The furnace is heated to 730 ° C. Start the vacuum pump and adjust the pressure to 25 mmHg (3.3 kPa). Methyl 3- (chloromethyl) -4-methylbenzoate solution is added dropwise over 1 hour 15 minutes. The product and unreacted starting material are collected in a cold trap. 200 m after cooling

The pyrolysis tube with acetone. The acetone solution is mixed with the ortho-xylene solution collected in the cooling trap. Acetone and ortho-xylene are distilled down to 16 in, Vigreaux Column, under normal pressure. When most of the ortho-xylene is distilled off, the system is made 0.5 mm Hg (67 Pa) and 15.5 g of pure methyl 3,4-cyclobutabenzoate are collected at 61 ° C. The residue remaining in the distillation pot is methyl 3- (chloromethyl) -4-methylbenzoate (23 g).

Experimental Example 2 to 12

The 120mm part of the furnace is a preheating zone, and the quartz tube filled with quartz chips is placed in an electric furnace whose temperature is 250 ° C. Insert an addition funnel on top of the quartz tube. The quartz tube is connected at the bottom to a trap and a vacuum pump or water aspirator.

The furnace is heated to the desired temperature as indicated by the thermal couple in the heat source extending to the center of the heating zone. Then vacuum. The solution in the addition funnel is added. The product and unreacted starting material are collected in a cold trap. The yield of the product is determined by gas chromatography. The material in the addition funnel is the starting material dissolved in ortho-xylene or toluene.

[Examples 2 to 5]

Examples 2 to 5 vary the ratio of solvent to starting material. The results are shown in Table I. Table I shows that the pyrolysis of methyl 3- (chloromethyl) -4-methylbenzoate using a ratio of the solvent to the starting material at 21 to 4 shows excellent selectivity and yield. Selectivity and mass balance are reduced only when the ratio of solvent to starting material is two.

TABLE 1

Ratio of Substrate to ¹ Diluent (Solvent)

^{2 Addition} rate of diluent and substrate to pyrolysis tube

³ Conversion refers to the mole percent of reactants converted to products and by-products.

⁴ Selectivity refers to the molar percentage of the desired product recovered as compared to the total product and by-products.

⁵ Yield refers to the mole percent of the desired product compared to the total reactants fed.

⁶ Mass balance is the mole percent of unreacted reactants and desired product compared to the total reactants fed to the reactor.

[Examples 6 to 8]

The pressure is changed during the pyrolysis of methyl 3- (chloromethyl) -4-methylbenzoate. The results are shown in Table II. Table II shows that the lower the reaction pressure, the better the yield of the product.

TABLE 2

¹ Ratio of Diluent (Solvent) to Substrate

^{2 Addition of} diluent and substrate to pyrolysis tube.

³ Conversion refers to the mole percent of reactants converted to products and by-products.

⁴ Selectivity refers to the molar percentage of the desired product recovered as compared to the total product and by-products.

⁵ Yield refers to the mole percent of the desired product compared to the total reactants fed.

⁶ Mass balance is the mole percent of unreacted reactants and desired product compared to the total reactants fed to the reactor.

[Examples 9 to 12]

Pyrolysis of 2-chloromethyl-1-methyl-benzene and methyl 3- (halomethyl) -4-methylbenzoate

In Examples 9 to 12, 2-chloromethyl-1-methylbenzene and methyl 3- (chloromethyl) -4-methylbenzoate are pyrolyzed. The results are shown in Table III.

TABLE 3

¹ conversion refers to the mole percent of reactants converted to products and by-products.

² Selectivity refers to the molar percentage of the desired product recovered as compared to the total product and by-products.

³ Yield refers to the mole percent of the desired product compared to the total reactants fed.

⁴ Mass balance is the mole percent of unreacted reactant and desired product compared to the total reactant fed to the reactor.

Claims (10)

Ortho-alkyl halomethyl aromatic hydrocarbons are dissolved in an inert solvent, and then ortho-alkyl having the formula (R ') ₂ -CH-, wherein R' is independently hydrogen or C _1-20 alkyl in each occurrence A pyrobutene ring is fused to an aromatic hydrocarbon by pyrolysing an ortho-alkyl halomethyl aromatic hydrocarbon solution in an inert solvent under conditions where the substituent and the halomethyl substituent form a cyclobutene ring. To prepare an aromatic hydrocarbon. The process of claim 1 wherein the weight ratio of solvent to ortho-alkyl halomethyl aromatic hydrocarbon is at least 2: 1. The method of claim 1 wherein the solvent is benzene, substituted benzene, diphenyl or substituted diphenyl. 4. The process of claim 3 wherein the solvent is benzene, toluene, xylene, chlorobenzene, nitrobenzene, alkylbenzoate, phenylacetate or diphenylacetate. The method according to claim 1, wherein the pyrolysis is performed at a temperature of at least 550 ° C. The method of claim 5 wherein the pyrolysis is carried out at a pressure of 10 to 760 mmHg (1.3 to 101.3 kPa). The method of claim 6, wherein the pressure is 25 to 75 mmHg (3.3 to 10.0 kPa). The process of claim 1 wherein the aromatic radical of the substituted aromatic hydrocarbon is benzene, naphthalene, phenanthracene, anthracene, biphenyl, vinaphthyl or diarylalkane. The process according to claim 1, wherein the ortho-alkyl halomethyl aromatic hydrocarbon corresponds to the following general formula (I), and the aromatic hydrocarbon to which the cyclobutene ring is fused corresponds to the following general formula (II).

In which R ¹ is independently at each occurrence hydrogen or C _1-20 alkyl; R ² in each occurrence is independently carbonyloxyhydrocarbyl, oxycarbonylhydrocarbyl, carboxamide, carboxy, carbonylhalo, cyano, nitro, hydroxy, hydrocarbyloxy or halo; X is chloro or bromo; a is an integer from 0 to 4. The compound of claim 9, wherein R ¹ is hydrogen or C _1-3 alkyl, R ² is carbonyloxyhydrocarbyl, oxycarbonylhydrocarbyl, carboxamide, carboxy, carbonylhalo, nitro or hydrocarbyloxy , X is chlorine and a is 1.