JPS62145030A - Production of phenylacetylene compound - Google Patents

Abstract

PURPOSE:To produce the titled substance easily in high yield, by the dehydrohalogenation of a dihalogenoethylbenzene or monohalogenostyrene in the presence of a basic substance, by adding an ethylene glycol compound to the reaction system. CONSTITUTION:The phenylacetylene compound of formula III is produced by the dehydrohalogenation reaction of a dihalogenoethylbenzene of formula I [R1 is (substituted) phenyl; R2 is H, alkyl or (substituted) phenyl; X is halogen] or a monohalogenostyrene of formula II in the presence of a basic substance (preferably NaOH) and an ethylene glycol compound at 60-80 deg.C. The ethylene glycol compound is the one represented by formula IV (R3 and R4 are H or 1-8C alkyl) and its amount is 0.3-7pts.wt. per 1pt.wt. of the raw material compound. EFFECT:The objective compound can be produced under mild condition without using particular reagent and expensive catalyst. USE:Intermediate for pharmaceuticals and agricultural chemicals and a raw material for polymer.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] Phenylacetylenes are valuable compounds as intermediates for pharmaceuticals and agricultural chemicals, or as raw materials for polymers.

[Prior art and its problems]

Various methods have been proposed for producing phenylacetylenes, but the industrially possible methods include dihalogenoethylbenzenes, which are halocane-formed styrenes;
Alternatively, monohalodenostyrenes are produced by intramolecular dehydrogenation of all monohalodenostyrenes.

Among these methods, the method using all dihalogenoethylbenzenes as raw materials is, for example, carried out by Chem.
Ber, Vol. 89, p. 1775 (I956), using dibromoethylbenzene as a raw material and using 4 times the mole of caustic potash, phenylacetylene was obtained in a yield of 65%.

Journal of the American Chemical Society (J, A, C, S) Volume 56, Page 2064 (I9
In 1934), phenylacetylene was obtained from dibromoethylbenzene with a yield of 66% using sodium metal and liquid ammonia, but this was a special reaction that used sodium metal and liquid ammonia, and the yield was also low. .

Furthermore, regarding the method using all the so-called phase transfer catalysts, Tetrahedron Letters (Tet, Rahedr et al.
on Let+ters)/1651 + 472
3 pages, 1976, Tetrahedron (Te1rahed)
ron) Volume 67, Volume 1656, 1981, and JP-A-56-13327, and the yield is 88% in the case of phenylacetylene. Using bromide, yields of 98% have been obtained only in petroleum ether. These methods also have industrial problems in that they use phase transfer catalysts that are expensive and special catalysts.

As a method using monohalogenostyrenes as a raw material, the above-mentioned J, A, C, Vol. 856, p. 2064 (I934) uses a liquid ammonium method using metals, which is problematic.

In addition, organic, synthesis (Org Syn,
) Collective Vol. 111, p. 67 (I922) describes that β-bromostyrene is melted in alkali.[Means for solving the problem] The present invention was achieved by solving the various problems of the proposed methods and conducting intensive studies to find a method that does not use special reagents or expensive special catalysts, can be used under mild conditions, and has a high yield. Reached.

That is, in the present invention, when dehydrohalogenating zohalodenoethylbenzenes represented by formula (I) or monohalogenostyrenes represented by formula (It) in the presence of a basic substance, ethylene glycols are Formula (II
This is a method for producing phenylacetylenes represented by I).

x (I1) R4-CH=C-R2 (III) R, -CmiC-R2 (However, R11R2: phenyl group, substituted phenyl group, hydrogen or alkyl group, with phenyl group or substituted phenyl group as essential) selected same or different groups;
Examples of the substituent include no-rodene, an alkyl group having 1 to 4 carbon atoms, a hydroxyl group, an alkoxyl group having 1 to 4 carbon atoms, and R2 is hydrogen, an alkyl group having 1 to 6 carbon atoms, a phenyl group, or , is a phenyl group substituted with the same substituent as R1, and X is a haloke97 atom, such as chlorine, bromine, or iodine.

Specifically, there are no particular limitations, but α,β-dichloro-ethylbenzene, α,β-cyfuromethylbenzene, o,
m, p-chloro-α, β-zochlor (or dibromo) ethylbenzene, o, m, p-bromo-α, β-zochlor (or dibromo) ethylbenzene, o, m, p-methyl-α, β-sochlor ( or cybrom) ethylbenzene,
o,m,p-methoxy-α,,β-dichlor (also 1d
Similom) ethylbenzene, o, m, p-hydroxy-
α,β-dichloro(or sibromo)ethylbenzene, 1
, 2-sibromo-1,2-zophenylethanatotheal.

Furthermore, in the monono-rodenostyrenes represented by formula (n) used in the present invention, R1 and R2 are the same as in formula (+), and one of Y is halogen and the other is hydrogen. Halogens include chlorine, bromine, and iodine.

Specifically, there are no particular limitations, but α-chloro (also 1d bromo) styrene, β-chloro (also ha, from) styrene, o, m, p-chloro-α-chloro (also hafrom)-
Styrene, o, m, p -7'lomo α-chloro (or bromo)-styrene, ' o, m, p-chloro-β-
Chlor (also hafrom)-styrene, o, m, p -7”
como-β-chloro(also hafrom)-styrene, o, m,
p-methyl-α-chloro(also hafrom)-styrene, o
, m, p -1 thyl-β-chloro(also hafrom)-styrene, o, m, p-methoxy-α-chloro-styrene,
o, m, p-methoxy-β-chloro-styrene, o, m
, p-hydroxy-α-chloro-styrene, 0. m, p
-hydroxy-β-chloro-styrene, and the like.

The basic substances used in the present invention include hydroxides and carbonates of alkali metals or alkaline earth metals, and specifically, sodium hydroxide, potassium hydroxide, calcium hydroxide, and sodium carbonate. , potassium carbonate, etc., and sodium hydroxide and calcium hydroxide are preferred, with sodium hydroxide being particularly preferred since it is inexpensive. The basic substance is preferably used in the form of solid or aqueous solution.
Alternatively, it is 1 to 10 times the stoichiometric amount, preferably 1 to 7 times the stoichiometric amount of monohaloke 9 nostyrene. If it is smaller than this range, the reaction rate will be slow and the reaction will not be completed, and if it is larger than this range, the cost will increase.

As the ethylene glycols used in the present invention, Teari,
These include ethylene glycol, diethylene glycol, triethylene glycol, higher polyethylene glycols, and mono- or sialkyl ethers thereof.

Specifically, there are no particular limitations, but examples include ethylene glycol and its mono- or diethers, diethylene glycol and its mono- or diethers, and triethylene glycol and its mono- or diethers.

The amount used is not particularly limited, but it is 0.1 to 10 times, preferably 0.3 to 7 times, the weight of dihalogenoethylbenzenes or monohalodefustyrenes.

The ethylene glycols used can be separated after the reaction, recovered without loss, and recycled.

In addition to ethylene glycols, solvents inert to the reaction may also be present, such as hydrocarbons such as hexane, heptane, benzene, and toluene, alcohols such as methanol, ethanol, impropatol, butanol, and dioxane. , tetrahydrofuran, cyinozolobyl ether, and other ethers.

The amount of these solvents to be used is not particularly limited, but is 1 to 10 times the weight of dihalogenoethylbenzenes or heptanohalogenstyrenes.

Furthermore, when a phase transfer catalyst is added to this reaction system, the reaction rate is slightly increased, but the reaction results remain unchanged.

The reaction temperature is 40 to 150°C, preferably 40°C.
-100°C1, particularly preferably 60-80°C.

If the temperature is too low, the reaction rate will be slow, and if the temperature is too high, the selectivity will decrease.

The reaction time is 1 to 15 hours.

After the reaction, highly pure phenylacetylenes can be obtained by distillation or the like.

Example 1 In a 200 m/4 L flask equipped with a stirrer, a thermometer, and a condenser, 26.4 V of sibromoethylbenzene was added.

Diethylene glycol motuptyl ether 10'OI゛, caustic potash 14.0,! i''& the mixture was placed in a 60°C oil bath and reacted at 60°C for 6 hours.After the reaction, the reaction mixture was cooled and analyzed by gas chromatography.
．． It was produced at a yield of 0% and 1.3%.

While adding water to the reaction solution, azeotropic distillation was carried out under reduced pressure, the fractions were separated, and the organic layer was rectified under reduced pressure to obtain 9.71 g (l[s195.2%) of phenylacetylene. .

Example 2 In the same manner as in Example 1, 30.1 g of a 50% aqueous sodium hydroxide solution was used in place of caustic potash, and a reaction was carried out at 6 ooc for 6 hours. When the reaction solution was similarly analyzed, it was found that 92.1% of bromustyrene of 5.3% phenylacetylene was produced.

Example 3 In the preparation of Example 1, dichloroethylbenzene 17.39e was used instead of sibromoethylbenzene, and 60
The reaction was allowed to proceed for 6 hours at °C. A similar analysis showed 72% phenylacetylene formation.

Example 4 In the charging tank of Example 1, β-monobromustine/18.3. ! 9'e was used to react at 60°C for 4 hours. In a similar analysis, 98.
Formation of 9% phenylacetylene was observed.

Example 5 Diethylene glycol monobutyl ether 'e20.9 was prepared in Example 1, and methanol sog was added accordingly.
'i was added, and the reaction was carried out in the same manner at 60°C for 6 hours. The reaction solution was analyzed and 96.5% of phenylacetylene was found to be produced.

Example 6 Diethylene glycol mono and butyl ether a2D, 9 were prepared in Example 1, and 80 g of hexane was added accordingly.
was added, and the reaction was carried out in the same manner at 60°C for 6 hours.

The reaction solution was analyzed and 96.4% production of phenylacetylene was observed.

Example 7 11.8N of β-methylstyrene, 16.0% of bromine in 100g of carbon tetrachloride. ! 9e was dropped. After completion of the dropwise addition, the mixture was left to stand overnight, and the solvent was distilled off under reduced pressure. Add 100 g of diethylene glycol monomethyl ether and 16 g of caustic soda to the remaining balance.
．． 0g' and reacted at 60°C for 6 hours. When the reaction solution was analyzed by gas chromatography, it was found to be 96.7%.
It was confirmed that phenylmethylacetylene was produced at a yield of .

Example 8 18.0 g of stilbene, 100 g of carbon tetrachloride. 16.0 gt of bromine was added dropwise into F. After completion of the dropwise addition, the mixture was allowed to stand overnight, and all the solvent was distilled off under reduced pressure. To this residue, 100.! ℃εrit21 Toluene was added to = $F1, extracted twice, and the primary layer was washed with saturated saline and concentrated under hydraulic pressure.The residue was distilled under reduced pressure (I71°
C/21 Hg) t,, 15.0.9 (yield 84
%) of zophenylacetylene was obtained.

Example 9 4-Methyl-sibromoethylbenzene 2.8,! 9,
Caustic force IJ 2.0,! 1.0 gt of 17zoethylene glycol monobutyl ether Reacted at 60°C for 6 hours. Analysis of the reaction solution revealed that 4-methylphenylacetylene was produced at a yield of 98.2%. Comparative Example The same procedure as in Example 6 was conducted except that diethylene glycol monobutyl ether was not used.

Analysis of the reaction solution revealed that the yield of phenylacetylene was
It was 4.3%.

〔Effect of the invention〕

The method of the present invention involves reacting dino-rogen or mono-roquene 9-isomer with a basic substance to produce phenylacetylenes, only in the presence of ethylene glycol, without requiring any other special conditions. First, phenylacetylenes can be produced in high yield.

Claims (1)

[Scope of Claims] When dehydrohalogenating dihalogenoethylbenzenes represented by formula (I) or monohalogenostyrenes represented by formula (II) in the presence of a basic substance, ethylene glycols are present in the presence of a basic substance. The expression (
A method for producing phenylacetylenes shown in III). (I) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (II) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (III) R_1-C≡C-R_2 [However, R_1, R_2: phenyl group, substituted phenyl group, The same or different groups selected from hydrogen or alkyl groups, with phenyl groups or substituted phenyl groups as essential. X: halogen]