JPH101453A - Production of benzyl acetate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain benzyl acetate by using an inexpensive alkali, because conventional method for producing benzyl acetate, which needs to use expensive anhydrous potassium acetate, is not satisfactory as industrial manufacturing method. SOLUTION: When producing benzyl chloride by reacting benzyl chloride with an alkali in the presence of an excess amount of acetic acid in water- containing state, the reaction is carried out in the presence of acetic acid in an amount of >=1.1mol and <=3mol based on 1mol benzyl chloride and an alkali in an amount of >=1.0 equivalent based on 1mol benzyl chloride and in a smaller number of equivalent than the number of mol of coexisting acetic acid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing benzyl acetate useful as a fragrance or the like.

[0002]

2. Description of the Related Art Conventionally, as a method for producing benzyl acetate, for example, German Patent No. 41507 describes a method in which benzyl chloride and anhydrous potassium acetate are reacted under heating and reflux in the presence of a large excess of glacial acetic acid.

[0003]

However, in the above-mentioned method, it is necessary to use expensive anhydrous potassium acetate, and it is hardly sufficient for an industrial production method.

[0004]

Means for Solving the Problems As a process for producing benzyl acetate, the present inventors have reacted industrially available and inexpensive alkali with benzyl chloride in a water-containing state. In this case, the reaction is performed in the presence of 1.1 to 3 mol of acetic acid and 1.0 or more equivalents of acetic acid to 1 mol of benzyl chloride and an equivalent number of alkalis smaller than the number of coexisting acetic acids. And a method for producing benzyl acetate.

Hereinafter, the present invention will be described in detail. In the present invention, the hydrated state is prepared at a charge ratio of 1.1 mol or more and 3 mol or less of acetic acid and 1.0 equivalent or more of alkali to 1 mol of benzyl chloride and an equivalent number smaller than the number of moles of acetic acid coexisting. This is a method for producing benzyl acetate.

[0006] The reaction temperature is carried out under heating to reflux, usually 1
In the range of 00 to 140 ° C, preferably 105 to 120 ° C.
It is in the range of ° C. The reaction can be carried out usually for 1 to 30 hours.

As the alkali used, for example, sodium hydroxide, sodium carbonate, sodium bicarbonate, potassium hydroxide, potassium carbonate and potassium bicarbonate are suitable.

In this reaction system, benzyl acetate can be obtained with a good reaction yield in a water-containing state. The water content of the reaction system is not particularly limited, but is usually in the range of 1 to 30%. For example, a system in which only acetic acid and neutralized water of alkali exist.

The reaction solution obtained by this reaction is separated, neutralized and concentrated to obtain benzyl acetate, which contains a small amount of benzyl alcohol. By-product benzyl alcohol can be converted to higher purity benzyl acetate by an ordinary method such as a reaction of the reaction solution with a small amount of acetic anhydride in the presence of sulfuric acid.

[0010] The reaction molar ratio of the present invention was examined for acetic acid.

The reaction was carried out by varying the number of moles of acetic acid with 1.1 mole of 50% aqueous sodium hydroxide solution per mole of benzyl chloride. The results are shown in Table 1.
If there is an excess mole number of 1.1 to 3.0 acetic acid relative to 1 mole of benzyl chloride, good results were obtained for both the benzyl chloride reaction rate and the benzyl acetate reaction yield.

When only 1 mol of acetic acid is present per 1 mol of benzyl chloride, both the benzyl chloride reaction rate and the benzyl acetate reaction yield decrease remarkably.

On the other hand, even if acetic acid is present in an amount exceeding 3 moles per mole of benzyl chloride, neither the benzyl chloride reaction rate nor the benzyl acetate reaction yield is improved.

From the results shown in Table 1, the molar ratio of acetic acid to be charged is preferably in the range of 1.1 to 3.0 mol per mol of benzyl chloride. Both benzyl acetate reaction yields are improved.

It is sufficient that the amount of sodium hydroxide is 1.0 mol or more per 1 mol of benzyl chloride as an aqueous solution.
If the amount of sodium hydroxide charged is less than 1 mole per mole of benzyl chloride, one of the resulting reaction materials, sodium acetate, will be less than 1.0 mole, and the benzyl chloride conversion will decrease. It is not appropriate. Further, as exemplified in Example 1, Example 2 and Comparative Example 1 in Table 1, the charged molar ratio of sodium hydroxide is preferably set to be equal to or less than the number of moles of coexisting acetic acid.
As exemplified in Comparative Example 1, when the molar ratio of sodium hydroxide charged was larger than the molar ratio of coexisting acetic acid, the benzyl chloride reaction rate and the benzyl acetate reaction yield were significantly reduced.

Table 2 shows the results obtained when sodium bicarbonate, sodium carbonate, potassium hydroxide, potassium bicarbonate and potassium carbonate were used as alkalis.

[0017]

According to the present invention, when producing benzyl acetate by reacting benzyl chloride with an alkali in the presence of an excess amount of acetic acid in the presence of water, 1.1 mole of benzyl chloride is added to 1 mole of benzyl chloride. Benzyl acetate can be obtained in good yield by reacting in the presence of at least 3 moles of acetic acid and at least 1.0 equivalent of an alkali and an equivalent number of alkalis smaller than the number of moles of acetic acid coexisting. Further, this method is advantageous in that it is industrially available and an inexpensive alkaline aqueous solution can be used.

[0018]

The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the present invention is limited thereto.

[0019]

Example 1 50% aqueous sodium hydroxide solution 253.4
224.60 g (3.74) of acetic acid was added to 0 g (3.17 mol) of acetic acid.
Mol) and 368.00 g (2.91 mol) of benzyl chloride, and the mixture was stirred at an internal temperature of 105 to 110 ° C for 15 hours while heating under reflux. The reaction solution was separated to remove the lower aqueous layer, and the upper organic layer was concentrated under reduced pressure. The resulting concentrated solution was sampled and subjected to gas chromatographic analysis to find that the benzyl chloride reaction rate was 95%, the benzyl acetate reaction yield was 78%, and the benzyl alcohol reaction yield was 15%.

[0020]

Example 2 The amount of acetic acid charged in Example 1 was 209.52 g.
(3.49 mol), and the others were the same as in Example 1. The results are shown in Table 1.

[0021]

Example 3 The amount of acetic acid used in Example 1 was changed to 192.06 g.
(3.20 mol), and the others were the same as in Example 1. The results are shown in Table 1.

[0022]

Example 4 The amount of acetic acid charged in Example 1 was 523.80 g.
(8.73 mol), and the others were the same as in Example 1. The results are shown in Table 1.

[0023]

Comparative Example 1 The amount of acetic acid charged in Example 1 was 174.60 g.
(2.91 mol), and the others were the same as in Example 1. The results are shown in Table 1.

[0024]

Comparative Example 2 The amount of acetic acid charged in Example 1 was 576.18 g.
(9.60 mol), and the others were the same as in Example 1. The results are shown in Table 1.

[0025]

[Table 1]

[0026]

Embodiment 5 In Embodiment 3, NaOH is used instead of NaOH.
Example 3 was repeated except that 266.28 g (3.17 mol) of HCO ₃ was used. The results are shown in Table-2.

[0027]

EXAMPLE 6 In Example 4, NaOH was used instead of NaOH.
The same operation as in Example 4 was performed except that 266.28 g (3.17 mol) of HCO ₃ was used. The results are shown in Table-2.

[0028]

Embodiment 7 In Embodiment 3, NaOH is used instead of NaOH.
_{The same} operation as in Example 3 was performed except that 167.48 g (1.58 mol) of ₂ CO ₃ was used. The results are shown in Table-2.

[0029]

Example 8 In Example 4, NaOH was used instead of NaOH.
_The procedure was performed in the same manner as in Example 4 except that 167.48 g (1.58 mol) of ₂ CO ₃ was used. The results are shown in Table-2.

[0030]

Embodiment 9 In Embodiment 3, KO was used instead of NaOH.
The same procedures as in Example 3 were carried out except for using 177.52 g (3.17 mol) of H. The results are shown in Table-2.

[0031]

Example 10 In Example 4, K was used instead of NaOH.
Example 4 was repeated except that 177.52 g (3.17 mol) of OH was used. The results are shown in Table-2.

[0032]

Example 11 In Example 3, K was used instead of NaOH.
The same operation as in Example 3 was carried out except that 317.00 g (3.17 mol) of HCO ₃ was used. The results are shown in Table-2.

[0033]

Example 12 In Example 4, K was used instead of NaOH.
The same operation as in Example 4 was performed except that 317.00 g (3.17 mol) of HCO ₃ was used. The results are shown in Table-2.

[0034]

Example 13 In Example 3, K was used instead of NaOH.
_{The same} operation as in Example 3 was carried out except that 218.04 g (1.58 mol) of ₂ CO ₃ was used. The results are shown in Table-2.

[0035]

Embodiment 14 In Embodiment 4, K is replaced by NaOH.
Example 4 was repeated except that 218.04 g (1.58 mol) of ₂ CO ₃ was used. The results are shown in Table-2.

[0036]

[Table 2]

Claims (1)

[Claims] (1) When producing benzyl acetate by reacting benzyl chloride with an alkali in the presence of an excess amount of acetic acid in the presence of water, 1.1 to 3 mol of benzyl chloride is added to 1 mol of benzyl chloride. A process for producing benzyl acetate, characterized in that the reaction is carried out in the presence of acetic acid and at least 1.0 equivalent of an alkali which is less than the number of moles of acetic acid coexisting.