JPS6039349B2 - Method for producing 2-cyanophenol derivatives - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a 2-cyanophenol derivative from a 2-hydroxybenzyl alcohol derivative, a nitrogen-containing compound, and oxygen in the presence of a metal catalyst.

2-cyanophenol derivatives are compounds useful as raw materials for the synthesis of various medicines, agricultural chemicals, and dyes.

Conventionally, the following method has been proposed as a method for producing cyanophenol derivatives from hydroxybenzyl alcohol derivatives.

That is, a method for producing penzonitrile by ammoxidizing sibenzyl alcohol with an oxygen-containing gas and ammonia in the presence of a copper catalyst [wBrackman Enei.
Rec, Trav, Chim. ,82,757(169
7)], the presence of water in the reaction system interferes with the ammoxidation reaction, so the reaction system must be kept in a non-aqueous state, and therefore it is necessary to dewater the raw materials and seal the reaction vessel. Industrially disadvantageous.

Furthermore, it was found that even when this method was applied to a reaction for producing a 2-cyanophenol derivative from a 2-hydroxybenzyl alcohol derivative, the yield of the target product did not improve. As a result of intensive research aimed at improving this method and producing 2-cyanophenol derivatives in high yield, the inventors unexpectedly found that in ammoxidation, which produces benzonitrile from benzyl alcohol, It was discovered that water, which had been interfering with the reaction, could be used as a reaction medium in the method of the present invention, and the present invention was achieved based on this discovery.

That is, this invention is based on the general formula (1) (wherein Y represents a lower alkyl group, a lower alkoxy group, or a halogen atom, and n represents 0, 1, or 2).

)2. A general method characterized by reacting a hydroxyl benzyl alcohol derivative, a nitrogen-containing compound selected from the group consisting of ammonia, urea and inorganic ammonium salts, and oxygen in a basic aqueous medium in the presence of a metal catalyst described below. Formula (0) (However, Y and n in the formula have the same meanings as above.

) The present invention relates to a method for producing a 2-cyanophenol derivative represented by: The 2-hydroxybenzyl alcohol derivative used in the method of this invention is represented by general formula (1).

(However, Y and n in the formula have the same meanings as above.

) Specific examples of 2-hydroxybenzyl alcohol derivatives include 2-hydroxybenzyl alcohol, 2-hydroxybenzyl alcohol substituted with a lower alkyl group, 2-hydroxybenzyl alcohol substituted with a lower alkoxy group, and 2-hydroxybenzyl alcohol substituted with a halogen atom. Examples include 2-hydroxybenzyl alcohol, and 2-hydroxybenzyl alcohol substituted with two or more substituents selected from a lower alkyl group, a lower alkoxy group, and a halogen atom.

Examples of the nitrogen-containing compound used in the method of the present invention include ammonia, urea, and inorganic ammonium salts, but various other amines can also be used.

Examples of inorganic ammonium salts include ammonium chloride, ammonium carbonate, and ammonium sulfate. Urea is particularly preferred when using a 2-hydroxybenzyl alcohol derivative substituted with a halogen atom. Ammonia can be used as liquid ammonia, ammonia gas, or an ammonia aqueous solution, and urea and inorganic ammonium salts such as ammonium chloride, ammonium carbonate, and ammonium sulfate can be used as they are or as aqueous solutions thereof.

The amount of ammonia, ammonium chloride, etc. used may be stoichiometrically equal to or more than the amount of 2-hydroxybenzyl alcohol derivative used, preferably 2950
The amount of urea, ammonium carbonate, ammonium sulfate, etc. used may be 1/2 mole or more, preferably 1 to 5 times the amount of the 2-hydroxybenzyl alcohol derivative used.

Oxygen in the method of this invention can be used as oxygen gas, an oxygen-containing gas diluted with an inert gas such as nitrogen, or air.

In particular, it is convenient and convenient to use air. The amount of oxygen supplied is 0.01 to INI/min per night of reaction solution, preferably 0.05 to 0. State 1/min.

When the amount of oxygen supplied is less than the above-mentioned range, the reaction rate becomes low, and even when the amount of oxygen is more than the above-mentioned range, there is no advantage in increasing the amount of oxygen supplied. In particular, copper,
An element, oxide, hydroxide, chloride, sulfate or acetate of a metal selected from the group consisting of iron, manganese, nickel, zinc, palladium and platinum, and further the aforementioned metal or metal compound and lead, Mixtures of metals selected from the group consisting of bismuth, tin and silver with nitrates or sulfates are useful.

The amount of metal catalyst used is 0.001 or more ta atoms, preferably 0.05 to 0.5 polyatoms, per mole of the 2-hydroxybenzyl alcohol derivative.

If the amount of metal catalyst used is less than 0.001 ta atoms per mole of 2-hydroxybenzyl alcohol derivative, the reaction rate will be extremely low, and if it is more than 0.5 ta atoms, there will be no particular effect. The basic aqueous medium is prepared by dissolving a basic substance in water, and examples of the basic substance include caustic soda, caustic potash, soda carbonate, and potassium carbonate.

The amount of the basic substance used is 1 to 10 times the amount of the 2-hydroxybenzyl alcohol derivative used, preferably 2 to 5 times the amount of the 2-hydroxybenzyl alcohol derivative used. In addition, as a basic aqueous medium,
Buffered solutions can also be used. Examples of such a buffer solution include an aqueous solution containing sodium carbonate and sodium hydrogen carbonate, an aqueous solution containing sodium monohydrogen phosphate and sodium phosphate, and an aqueous solution containing sodium monohydrogen phosphate and sodium phosphate. The concentration of the 2-hydroxybenzyl alcohol derivative in the reaction mixture is usually suitably 0.2 to 50% by weight, particularly preferably 0.5 to 15% by weight.

The reaction temperature is preferably 80 to 140 pm, particularly 90 to 130 pm. Further, the reaction pressure may be normal pressure or increased pressure. The reaction time varies depending on the type and amount of the 2-hydroxybenzyl alcohol derivative, the reaction temperature, etc., but usually
It takes 2 to 5 hours. After completion of the reaction, the 2-cyanophenol converter can be isolated from the reaction product solution obtained, for example, by the following operation. After adding potic acid such as hydrochloric acid or sulfuric acid to the reaction product solution until its pH value becomes 5 or less, the 2-cyanophenol derivative is extracted with an organic solvent such as ether, benzene, toluene, or xylene.

Then, the 2-cyanophenol derivative is isolated by distilling this organic solvent layer. The 2-cyanophenol derivative obtained by the method of this invention is represented by the general formula (b). (However, in the formula, Y and n have the same meanings as above.

) 2-cyanophenol derivatives, for example, 2-cyanophenol, 2-cyanophenol substituted with a lower alkyl group, 2-cyanophenol substituted with a lower alkoxy group, 2-cyanophenol substituted with a halogen atom, and , a lower alkyl group, a lower alkoxy group, and a 2-cyanophenol substituted with two or more substituents among halogen atoms.

By carrying out the method of this invention, 2-cyanophenol derivatives can be produced in high yield and high selectivity.

Next, examples of this invention will be shown.

Examples 1 to 20 In an autoclave, a metal catalyst was added to a solution in which 5 hmol of a 2-hydroxybenzyl alcohol derivative and 6 moles of caustic soda were dissolved in 91 mol of ammonia water (containing 2% by weight of ammonia), and mixed. Total amount with additional water: 5
00' reaction mixture was charged.

While circulating air through this reaction mixture at a flow rate of 0.2 mm/min, the flow rate was 3.5 mm at 2 k9/ground (gauge) and 12,500 yen under Azusa. A time reaction was performed. After the reaction was completed, a homogeneous solution was obtained by extracting the metal catalyst from the reaction product.

After adjusting the pH value to 2 by adding 20 parts of 12N hydrochloric acid to this solution, it was extracted five times with 500 parts each of ethylphenol, and the extract was analyzed by gas chromatography. The results are shown in Table 1. Table 1 Examples 21 to 24 In an autoclave, a metal catalyst was added and mixed to a solution of 5 hmol of 2-hydroxybenzyl alcohol derivative and 6 moles of caustic soda, and water was added to the total amount of 50
0' of reaction mixture was charged.

While flowing the reaction mixture at a flow rate of 0.0 mm/min of ammonia gas and 0.2 mm/min of air, 2 k9
/ ground (gauge), fly Azusa 125q0 3. An intervowel response was performed. After the reaction was completed, the reaction products were converted into Examples 1 to 20.
processed in the same way.

The results are shown in Table 2. Table 2 Examples 25-32 In an autoclave, 5 hmol of 2-hydroxybenzyl alcohol derivative, 6 moles of caustic soda, and nitrogen-containing compounds (10 moles of urea, 10 moles of ammonium chloride, 20 moles of ammonium carbonate, 23 moles of ammonium sulfate) were added. A metal catalyst was added and mixed to a solution dissolved in water, and water was further added to prepare a reaction mixture having a total volume of 500 m'.

While air was flowing through the reaction mixture at a flow rate of 0.2 mm/min, it was heated to 125 mm using a 2k9/c gauge.
So 3. A time reaction was performed. After the reaction was completed, the reaction products were treated in the same manner as in Examples 1-20. The results are shown in Table 3. Table 3 Note that the reaction rate and selectivity were calculated using the following formula.

Claims (1)

[Claims] 1 General formula (1) (1) General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (However, in the formula, Y represents a lower alkyl group, a lower alkoxy group, and a halogen atom, n represents 0, 1 and 2), a nitrogen-containing compound selected from the group consisting of ammonia, urea and inorganic ammonium salts, and oxygen combined with copper, iron,
In the presence of a metal catalyst using an element, oxide, hydroxide, chloride, sulfate or acetate of a metal selected from the group consisting of manganese, nickel, zinc, palladium and platinum,
The general formula (
II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (However, Y and n in the formula have the same meanings as above.) A method for producing 2-cyanophenol derivatives. 2
As metal catalysts (i) copper, iron, manganese, nickel,
elemental metal, oxide, hydroxide, chloride, sulfate or acetate selected from the group consisting of zinc, palladium and platinum; and (ii) selected from the group consisting of lead, bismuth, tin and silver. A method for producing a 2-cyanophenol derivative according to claim 1, characterized in that a metal nitrate or sulfate is used.