JPH04221354A - Production of tert. butyl hydrazine - Google Patents

Abstract

PURPOSE:To industrially and advantageously obtain tert. butylhydrazine. CONSTITUTION:A hydrazine monohydrohalide salt is reacted with tert. butyl alcohol in the presence of phosphoric acid of 0.2-1.5mol based on 1mol hydrazine monohydrohalide salt to produce tert. butylhydrazine monohydrohalide salt.

Description

Description: [0001] The present invention relates to an industrially advantageous method for producing tert-butyl hydrazine, and more specifically, the present invention relates to an industrially advantageous method for producing tert-butyl hydrazine. The present invention relates to a method for producing tert-butylhydrazine, which comprises reacting the following in the presence of a specific amount of phosphoric acid. [Prior Art] Tert-butylhydrazine (hereinafter referred to as
Regarding the production method of t-BuH (sometimes abbreviated as t-BuH), several proposals have been known in the past. ``A method for producing tert-butylhydrazine hydrohalide, which comprises reacting hydrazine dihydrohalide with libbutanol in the presence of hydrazine dihydrohalide or hydrogen halide.'' According to the above proposal, tert-butylhydrazine monohydrohalide (hereinafter referred to as t-BuH.
When producing hydrazine monohydrohalide (sometimes abbreviated as H . And in this proposal, it is true that H
・Although the production yield of t-BuH・HX with respect to HX is high,
Since the solubility of the t-BuH・HX in the solvent in the reaction system is extremely high, the t-BuH・HX has a very high solubility in the solvent in the reaction system.
The actual yield of uH・HX is extremely low at about 7%.
To overcome this problem, recycling and reuse of the reaction solution has been proposed, but it is completely insufficient from the viewpoint of time and production volume per unit, and it is difficult to say that it is an industrially advantageous method. There were also problems with the purity of the product. Furthermore, this proposal does not include any description or suggestion regarding the presence of phosphoric acid as an essential component as in the present invention and the outstanding effects thereof. [0004] The present inventors discovered that the presence of an excess of hydrohalic acid is not necessarily an indispensable condition, and that a similar reaction proceeds even in the presence of a phosphorous oxygen acid such as phosphoric acid. An application was filed (Japanese Unexamined Patent Publication No. 60-2370)
No. 59). This application is based on “Hydrazine (NH2NH2)
and a monohydric alcohol (ROH, in which R represents an alkyl group), hydrohalic acid (HX, in which X
represents a Cl or Br atom) in the presence or absence of a phosphorous-containing oxygen acid. . ", and Example 14 thereof describes the synthesis of t-BuH in the presence of 1 mole of hydrobromic acid and 0.1 mole of orthophosphoric acid per mole of hydrazine hydrate. There is. [0005] This proposal is based on the target compound t-
Although the yield of BuH.HX was considerably improved to 34%, the purity of the hydrohalide salt was 94% by weight, which was not necessarily sufficient. Problems to be Solved by the Invention As a result of detailed studies in order to solve the above-mentioned problems of the prior art, the present inventor found that when phosphoric acid is used instead of hydrohalic acid, the phosphoric acid becomes H. It acts as a catalyst in the reaction between HX and tertiary butyl alcohol (hereinafter sometimes abbreviated as t-BuOH), and also serves as a solvent for the reaction, and also acts as a solvent for the reaction between HX and tertiary butyl alcohol (hereinafter sometimes abbreviated as t-BuOH). is relatively difficult to dissolve, but the starting material, hydrazine monohydrohalide, has a relatively high solubility. By controlling the amount of phosphoric acid used within a certain range, highly pure t-BuH.HX crystals can be obtained. can be precipitated, and by simply performing the simple operations of filtering, washing, and drying these crystals, t with a purity of 98% by weight or more can be obtained.
-BuH.HX crystals can be obtained with a yield of 50% or more, and the present invention has been completed. Means for Solving the Problems The present invention provides a method for producing tert-butylhydrazine by reacting hydrazine monohydrohalide and tert-butyl alcohol in the presence of phosphoric acid. The present invention relates to a method for producing tert-butylhydrazine, characterized in that it is present in an amount of 0.2 to 1.5 moles per mole of hydrazine monohydrohalide. The present invention will be explained in detail below. Examples of H/HX, which is a starting material of the present invention, include hydrazine monohydrochloride (hereinafter sometimes abbreviated as H.HCl), monohydrobromide (hereinafter abbreviated as H.HBr) ), monohydriodide, monohydrofluoride, etc., H.HCl and H.H.
Preference is given to using Br. [0009] The above H/HX may be directly subjected to the reaction in the form of a salt, but is not limited to this. For example, it may be provided in the form of an aqueous hydrazine solution and an aqueous solution of hydrohalic acid, and then added to the reaction system. After neutralization and formation, it may be used after being concentrated to a predetermined concentration, if necessary. t-BuOH used in the method of the present invention
Any commercially available t- may be used, and there is no particular limitation, but any t- Even BuOH can be used. Usually 9
A product with a purity of 5% by weight is recommended. [0011] The amount of t-BuOH used is H.HX1
Generally 1 to 2 mol, preferably 1.0 to 2 mol
The amount is preferably about 1.2 mol. If the usage amount is above the lower limit value, unreacted H・HX is generated t-BuH・HX
The resulting t-B
This is preferable because it is possible to prevent a decrease in the purity of uH・HX and maintain a good reaction rate.On the other hand, if it is below the upper limit, excess t-BuOH
This is preferable because it can suppress the mixing of t-BuH.HX with t-BuH.HX. [0012] t-BuOH is preferably added sequentially to the reaction system maintained at 90 to 130°C. According to this addition method, the reaction can proceed under normal pressure, and there is no need to use a special reaction device such as an autoclave, which is practical. Further, it is possible to easily remove water generated during the reaction, control the reaction temperature, manage the liquid composition, etc. [0013] When adding t-BuOH sequentially, analyze the reaction solution, and add sequentially until the composition molar ratio of H.HX and t-BuH.HX in the reaction solution becomes 0.3 or less, and allow the reaction to occur. It is preferable. By setting the molar ratio below the above, it is possible to suppress the starting material H.HX from being mixed into the product t-BuH.HX crystals, and to prevent a decrease in purity, which is preferable. The phosphoric acid used is preferably added to the reaction system as an aqueous solution. The concentration of phosphoric acid is not particularly limited, but any concentration within the range of 10 to 100% by weight can be recommended. If the concentration is lower than this, water can be removed from the reaction system by distillation or the like prior to or during the reaction to achieve a concentration that produces the same effect. The amount of phosphoric acid used is 0.2 to 1.5 mol, preferably 0.4 mol to 1 mol of H.HX as the starting material.
~0.6 mol. If the amount used is too small (less than the lower limit), the catalytic effect will be weak and the reaction will take a long time.
This is not preferable because the purity of the crystals produced will be poor. On the other hand, if the amount exceeds the upper limit, the produced t-BuH.
This is not preferable because the amount of HX dissolved increases and the yield decreases. The reaction in the method of the present invention can be carried out under atmospheric pressure conditions, and although it is not necessary to particularly adopt pressurized conditions, pressurized conditions can be adopted if desired, for example, at atmospheric pressure to An example of the pressure condition is about 15 kg/cm2. The reaction temperature in the method of the present invention is 90
~130°C can be suitably used, preferably 100~11
0℃ is recommended. If the reaction temperature is above the lower limit,
It is preferable that it has an appropriate reaction rate and that it is below the upper limit because it can suppress the side reaction of t-BuOH to isobutylene. The reaction time is usually about 5 hours. Depending on the capacity of the reactor, it is possible to complete the reaction in a shorter time, but the reaction time is
It is practical to determine it by the compositional molar ratio of and t-BuH.HX. Furthermore, by managing the reaction solution during the reaction, the filtrate can be recycled and reused to further improve productivity. The t-BuH.HX thus obtained is neutralized, for example, by adding an appropriate alkaline compound, and if desired, the alkali salt formed is filtered off and distilled to collect free t-BuH. can do. Usable alkali compounds include, for example, alkali metal or alkaline earth metal hydroxides such as sodium hydroxide, potassium hydroxide, calcium hydroxide, barium hydroxide;
Examples include alkali metal carbonates such as sodium carbonate and potassium carbonate. [0021] The reaction format is, for example, batch type, semi-batch type,
It may be carried out in any continuous mode. [Examples] Hereinafter, the state of implementation of the present invention will be explained in more detail with reference to Examples and Comparative Examples. Example 1 H.HCl was added to a 300 ml separable flask.
5 g (1.00 mol) and 32% by weight aqueous phosphoric acid solution 61.
3g (0.20 mol) of t-Bu was charged and heated while stirring.
74.1g (1.00mol) of OH at 100-105℃
It was dripped for 5 hours. After the addition was completed, the solution was stirred at the same temperature for another 30 minutes and analyzed by liquid chromatography, and the yield of t-BuH.HCl was 76.
It was 9%. This solution was cooled to 20°C, and the precipitated crystals were separated and dehydrated using a centrifuge. Further, 10 g of water was sprayed and washed to obtain wet crystals of t-BuH.HCl. When this was dried in a vacuum dryer kept at 50°C (2 Torr or less), the purity was 99.1% by weight (H・HCl
Crystals containing 0.6% by weight) were obtained with an isolated yield of 42.6% (based on the charged H.HCl). Examples 2 to 3 and Comparative Examples 1 to 2 The reaction was carried out in almost the same manner as in Example 1 except that the amount of the phosphoric acid aqueous solution used was changed, and t-BuH.HCl crystals were isolated by the same treatment. I got it. The amount of phosphoric acid aqueous solution used and t-
Table 1 shows the production yield of BuH.HCl and the isolation yield of t-BuH.HCl crystals. Comparative Example 3 Into the same apparatus as in Example 1, 68.5 g of H.HCl (1
．． 00 mol) and 150.9 g of 29% by weight aqueous hydrochloric acid solution (
1.20 mol) and t-BuOH under heating and stirring.
74.1g (1.00mol) at 100-105℃
It dripped over time. After the addition was completed, the solution was stirred at the same temperature for another 30 minutes and analyzed by liquid chromatography, and the yield of t-BuH HCl was 72.2%.
Met. This solution was treated in the same manner as in Example 1 to obtain t-BuH.
- HCl crystals were isolated and obtained. The amount of hydrochloric acid aqueous solution used, the production yield of t-BuH・HCl, and the t-BuH・
The isolated yield of HCl crystals is shown in Table 1. Example 4 Into the same apparatus as in Example 1, 113.0 g of H.HBr (
1.00 mol) and 57.6 g of 85% by weight phosphoric acid aqueous solution (0
．． 50 mol) and heated with stirring to make a homogeneous solution.
BuOH 74.1g (1.00 mol) from 100 to 10
The mixture was added dropwise at 5°C over 3.5 hours. After dropping, add 3 more
After stirring at the same temperature for 0 minutes, the resulting solution was analyzed by liquid chromatography, and the yield of t-BuH•HBr was 85.8%. Add 50g of water to this solution 2
Cooled to 0°C and treated in the same manner as in Example 1 to obtain t-
Wet crystals of BuH/HBr were obtained and dried in the same manner,
Crystals of t-BuH•HBr with a purity of 98.3% by weight were obtained at an isolated yield of 61.0% (based on the charged H•HBr). [Table 1] Example 5 Using the same apparatus as in Example 1, the mother liquor and washing liquid obtained in Example 1 were combined (138.0 g in total), and the reaction liquid was concentrated by heating and washed. After distilling off water and the amount of water produced in the reaction, equimolar H.HCl to the isolated and obtained t-BuH.HCl.
29.2 g (0.426 mol) was added, and the total number of moles of t-BuH・HCl and H・HCl (hereinafter sometimes referred to as hydrazine component) in the charged reaction solution was 1
．． 00 mol] was adjusted. Under heating and stirring, 100~
31.6 g of t-BuOH (0
．． 426 mol) was added dropwise. After the addition was completed, the mixture was stirred at the same temperature for another 30 minutes, and the resulting solution was analyzed by liquid chromatography, and it was found that 0.758 mol of t-BuH.HCl was present in the reaction solution. This solution was cooled to 20°C, the precipitated crystals were fed to a centrifuge, separated and dehydrated, and further 1
Washing treatment was performed by spraying 0 g of water to obtain wet crystals of t-BuH.HCl. This was kept in a vacuum dryer (2T) kept at 50℃.
46.8 g of crystals with a purity of 98.7% by weight were obtained. The isolation yield was 37.6% based on the hydrazine component in the charged reaction solution and 88.3% based on the added H.HCl. [0030] The same process was repeated three times in total. The results are shown in Table 2. [Table 2] [Effect of the invention] As is clear from the results of the above examples and comparative examples, when the amount of phosphoric acid used is too small, less than 0.2 mol per 1 mol of H. , reaction rate, t-
Both BuH and HX production yields are insufficient, so t
The isolation yield of -BuH·HX crystals was also at a low level. (Comparative Example 1) In addition, if the amount of phosphoric acid used is too large, exceeding 1.5 mol per 1 mol of H.HX, t-Bu
Although the H.HX production yield was sufficiently high, the t-BuH.H
Since X dissolves in phosphoric acid in the reaction system, the t-BuH・H
The isolated yield of X crystals was low. (Comparative Example 2) Furthermore, when only hydrohalic acid was used without using phosphoric acid, the purity of isolated t-BuH/HX crystals decreased due to precipitation of hydrazine hydrohalide, etc. Therefore, the concentration of the hydrohalic acid cannot be made very high, and therefore the reaction rate is not very fast. Above all, due to the high water solubility of the produced t-BuH. The isolation yield of BuH·HX crystals was extremely low. (Comparative Example 3) On the other hand, by adjusting the amount of phosphoric acid used in the range of 0.2 to 1.5 mol per 1 mol of H.HX according to the method of the present invention, high reaction rate, It was possible to obtain t-BuH.HX with a high production yield, and moreover, it was possible to obtain highly purified t-BuH.HX crystals with an excellent isolation yield. (Examples 1 to 4)

Claims (1)

[Claims] Claim 1: A method for producing tert-butylhydrazine by reacting hydrazine monohydrohalide and tert-butyl alcohol in the presence of phosphoric acid, in which phosphoric acid is added to 1 mole of hydrazine monohydrohalide. A method for producing tert-butylhydrazine, characterized in that the amount of tert-butylhydrazine is present in an amount of 0.2 to 1.5 mol.