JPH06316404A - Preparation of chloramine - Google Patents

Abstract

PURPOSE: To safely obtain a hydrocarbyl substituted chloramine without producing any amine hydrochloride (e.g. NH₄Cl) by reacting an alkali (alkaline earth) metal amide, NH₃ or prim. (sec.) amine with a chlorinating agent selected from Cl₂, hypochlorite and chlorine monoxide.

CONSTITUTION: This reaction is a preparing method of a chloramide which is necessary for a preparation of an anhydrous hydrazine and a hydrocarbyl substd. hydrazine. In the reaction formula, X is H or alkali (alkaline earth) metal; Y is a chlorinating agent residue; R₁, R₂, R₆ and R₇ are each H or hydrocarbyl; R₃, R₄, R₅ are hydrocarbyl. In the chloramine producing reaction A, formula (I) is an alkali metal amide or the like, formula (II) is a chlorinating agent and formula (III) is a chloramine. tert. Amine of formula (IV) is reacted with a chloramine and a tert. hydrazinium chloride of formula (V) is obtained (reaction B). With this an alkali metal amide is reacted and a hydrocarbyl substd. hydrazine (VII) is obtained (reaction C).

COPYRIGHT: (C)1994,JPO

Description

Detailed Description of the Invention

The present invention relates to a method for producing chloramine.

Hydrazines, alkyl-substituted hydrazines, in particular asymmetric dimethylhydrazine (VDMH), and phenyl-substituted hydrazines have a wide range of applications, for example important intermediates for the preparation of pharmaceuticals, fuels, agricultural products, blowing agents and the like. It is a commercial compound.

A number of methods have traditionally been used to produce hydrazine and its derivatives. For example, the Rasching method is a commercial synthesis of hydrazine from chloramine and ammonia in aqueous solution. Initially, sodium hypochlorite is reacted with an excess amount of ammonia to produce chloramine, and sodium hydroxide is produced as a by-product. Chloramine is then reacted with ammonia to produce hydrazine. In the first step of this method, chloramine forms rapidly. However, the second
At the stage, the reaction of chloramine with ammonia is slow and requires heat to complete. The rate of formation of the hydrazine product increases with temperature. As a side reaction, hydrazine reacts with the starting chloramine to form ammonium chloride and nitrogen. In order to avoid the undesirably high rate of decomposition of hydrazine due to this undesired side reaction, the process uses high temperature (about 130 ° C.) and a large excess (20: 1 to 30: 1) of ammonia. It should be carried out to minimize the reaction of the hydrazine product with the chloramine reaction component. The desired hydrazine product is present in the final reaction mixture at a relatively low concentration (generally 1% to 3%).
%), And the reaction mixture contains considerable water, so the recovery of anhydrous hydrazine from this mixture has considerable cost.

The Olin method (Kobe et al., Advanced i
n Petroleum Chemistry and Refining, Vol. 2. Inters
ience Pub. Inc. New York, NY, 1959, Chapter 9)
Is a modification of the Raschig process using anhydrous ammonia, which is injected under pressure into an aqueous chloramine solution. Due to the dilution, the temperature of the reaction mixture is about 130 ° C.
, Which is the optimum temperature for the reaction of ammonia with chloramine. However, additional heat must be supplied from an external fuel source to complete the reaction and separate a relatively small concentration of hydrazine from a fairly large volume of ammonia in a subsequent distillation step. More energy is required to remove sodium chloride and sodium hydroxide byproducts and recover hydrazine. As in the Raschig method, hydrazine is recovered as a monohydrate. Substantial additional energy is required to drive out chemically bound water to obtain a pure anhydrous product.

The Schestakoff method is based on the decomposition of urea with sodium hypochlorite to form hydrazine. This reaction is similar to the Hoffman method of making primary amines from amides. In this method, a cold aqueous solution of urea and sodium hydroxide is added to a cold aqueous solution of sodium hypochlorite. The heat of reaction raises the temperature to 100 ° C., at which temperature the reaction takes place at a relatively high rate. A large amount of steam must be used to prepare the urea solution (43% solution) to compensate for the large endotherm of the solution. The product is a much lower concentration (about 3%) of hydrazine monohydrate in the commercial process described above. Additional energy is required for concentration, hydrate conversion and fractionation of the final hydrazine product. Excessive amounts of alkali and alkali salts are formed as by-products (by-product to N ₂ H ₄ thus produced weight ratio of about 12: 1),
These are not reusable in this way.

Bergbau or Beye
The method of r) is still another commercial method for producing hydrazine. The energy requirements of the Bergbau process are not as great as in the commercial processes mentioned above. In this method, ammonia is reacted in the presence of chlorine and a ketone to produce the intermediate diazocyclopropane or ketazine. This intermediate is then hydrolyzed to form hydrazine hydrate, the latter being converted to the desired anhydrous product. The energy requirements for recovery of hydrazine are similar to the commercial methods described above, including recovery from anhydrous reaction mixtures.

Thus, most well-known and widely practiced processes for the preparation of hydrazine produce hydrazine hydrates and require substantial energy to recover the anhydrous product.

Given the ever-increasing cost of energy, minimizing energy over-use in the thermodynamic requirements required to complete a given reaction is crucial. When considering the total energy requirements of any chemical method, the energy required to produce the raw materials and auxiliary chemicals must also be considered. Thus, in the case of hydrazine, N
The energy requirement to provide H ₃ , Cl ₂ , NaOCl, urea, NaOH, etc. is an important factor in determining the degree of energy loss or gain required to make the final product. Similarly, the weight ratio of by-product to desired end product must be evaluated as another important factor in the overall efficiency of a given process. In light of this, the above-mentioned prior art processes for producing hydrazine are decisive for non-critical, especially considering that 58 kcal / mol of product hydrazine is lost from the system during the formation of hydrazine hydrate. It is efficient.

The process currently used in the commercial production of UDHM consists of nitrosating the dimethylamine sulfate with sodium nitrite to form dimethylnitrosamine, which is reduced to the desired product. In addition to suffering from many of the drawbacks mentioned above with respect to the hydrazine method, dimethylnitrosamine, which is produced as an intermediate in this method, is a known carcinogen, and is not only limited to personnel performing the method, The environment is similarly exposed to potential dangers. Because of this potential danger, Occupational Saftey and Health Admi
nistration) (OSHA) has enforced strict rules governing manufacturing using or manufacturing nitrosamines.

Many of the deficiencies and risks inherent in the prior art have been overcome by the method described in my US Pat. No. 4,286,108. This method comprises adding a tertiary hydrazinium halide to a compound selected from the group consisting of alkali metal amides, alkaline earth metal amides, hydrocarbyl substituted alkali metal amides or hydrocarbyl substituted alkaline earth metal amides, and a non-aqueous inert carrier. To produce a hydrazine and a hydrocarbyl-substituted hydrazine.

One of the reaction components used in the production of the tertiary hydrazinium halide by the method of US Pat. No. 4,286,108 is chloramine produced by reacting ammonia gas with chlorine. The by-product of this reaction is ammonium chloride, which tends to clog the feed lines for the reaction components and generally interferes with the operation of the process.

According to the present invention, an alkali metal amide, an alkaline earth metal amide, a hydrocarbyl-substituted alkali metal amide, a hydrocarbyl-substituted alkaline earth metal amide, ammonia, or a primary or secondary amine is reacted with a chlorinating agent. To form chloramine or hydrocarbyl-substituted chloramine without simultaneously producing ammonium chloride, and reacting the chloramine thus produced with a tertiary amine to produce a tertiary hydrazinium chloride, and a tertiary hydrazinium Reacting a chloride with an alkali metal amide, an alkaline earth metal amide, a hydrocarbyl-substituted alkali metal amide or a hydrocarbyl-substituted alkaline earth metal amide to produce the desired product under substantially anhydrous conditions. , Anhydrous hydrazine and Improved method for producing the Hidorakarubiru substituted derivative.

The term "hydrocarbyl" as used herein is obtained by removing a hydrogen atom from a parent hydrocarbon.
Means a valent residue. A typical example of a hydrocarbyl group is 1
Alkyl having ~ 25 carbon atoms, such as methyl, ethyl, propyl, butyl, pentyl, hexyl,
Heptyl, octyl, nonyl, undecyl, decyl, dodecyl octadecyl nonadecyl, eicosyl, heneicosyl, docosyl, tricosyl, tetracosyl, pentacosyl and their isomers; aryl of 6 to 25 carbon atoms, for example phenyl, tolyl, xylyl, Naphthyl, biphenyl, tetraphenyl and the like; aralkyl of 7 to 25 carbon atoms, such as benzyl, phenethyl, phenpropyl, phenbutyl, phenhexyl, naphthooctyl and the like; cycloalkyl of 3 to 8 carbon atoms, such as cyclopropyl, Cyclobutyl,
Examples include cyclohexyl, cycloheptyl, cyclooctyl and the like.

The term "alkali metal" as used herein is intended to include lithium, sodium, potassium, rubidium and cesium.

As used herein, the term "alkaline earth metal" is intended to include magnesium, calcium, barium and strontium.

As used herein, the term "non-aqueous reaction medium" means a liquid solvent or liquid for the reaction components used herein that does not adversely affect the desired course of the reaction and is substantially free of water. It is intended to mean a solid carrier. "Substantially free of water" means 1% by weight
It is meant to contain less, preferably less than 0.1% water. Examples of such carriers are dried kerosene (preferably low sulfur content and freshly distilled), trialkylamines such as tripropylamine and tributylamine, carbon tetrachloride, alkyl ethers, and mixtures thereof. Is. It has been found that the use of kerosene as the reaction medium in each step of this method significantly increases the yield of hydrazine or hydrocarbyl substituted hydrazine.

In a preferred embodiment of the invention there is provided a process for the preparation of anhydrous hydrazine, which has very favorable thermodynamics. In this preferred method, chlorine is reacted with an alkali metal amide such as soda amide or lithium amide to produce chloramine and the corresponding alkali metal salt. The chloramine thus produced reacts with a tertiary amine to form a tertiary hydrazinium chloride, which in turn reacts with an alkali metal amide to produce anhydrous hydrazine.

All of the by-products of this preferred embodiment can be conveniently recovered. It is a commercially useful substance. Most of these materials can be recycled and used as starting materials in certain steps of the process or serve as starting materials for said starting materials.

As will be apparent from the detailed description which follows, it has all of the advantages of the inventor's original invention which is included in US Pat. No. 4,286,108. That is, the process does not require specialized equipment, the cost of the reaction components is minimized, and the desired product is easily obtained using standard recovery techniques. Furthermore, anhydrous hydrazine and hydrocarbyl-substituted hydrazine can be obtained in the reaction mixture at relatively high concentrations (on the order of 25-50%). Another distinct advantage of the process of the present invention is that it does not simultaneously produce ammonium chloride which may interfere with the efficient operation of the process.

Another significant advantage of the present invention is that it provides a relatively safe procedure for the preparation of hydrocarbyl substituted hydrazines, especially UDMH. Unlike the methods currently used for the production of such products, the method of the present invention is carried out under conditions that cause little or no harm to workers or the environment.

The process according to the invention is then carried out according to the general reaction scheme: Wherein X represents hydrogen, an alkali metal or an alkaline earth metal, R ₁ and R ₂ are the same or different,
And represents hydrogen or a hydrocarbyl group, Y represents a residue of a chlorinating agent, R ₃ , R ₄ and R ₅ are the same or different and represent a hydrocarbyl group, and A is an alkali metal or an alkaline earth metal. And R ₆ and R ₇ are the same or different and represent hydrogen or a hydrocarbyl group.

When carrying out the reaction to form chloramine (Reaction A), a compound of formula I, such as an alkali metal amide, an alkaline earth metal amide, ammonia, or a primary or secondary amine, is added to the chlorinating agent of formula II. React with.
The reaction components of formula I are well known and their methods of preparation are also well known. The chlorinating agent used in this reaction is selected from chlorine, hypochlorous acid and chlorine monoxide. The latter two chlorinating agents are conveniently prepared from alkali metal or alkaline earth metal hypochlorites. Details of this manufacture are given in the examples below. The use of these two chlorinating agents in the production of hydrocarbyl substituted chloroamines without the simultaneous production of amine hydrochloride is considered to be a particularly significant and innovative aspect of the present invention.

It is a brief explanation of the process of the present invention that reactions involving the formation of chloramines, such as reactions of chlorine with ammonia, which simultaneously produce amine hydrochlorides such as ammonium chloride, are not within the scope of the present invention. You can understand from Generally, when chlorine is used as the chlorinating agent in this process, it is desirable to use an alkali metal amide or an alkaline earth metal amide as the compound of formula I to prevent the simultaneous formation of ammonium chloride.

Hypochlorous acid or chlorine and mono- and di-
Reaction with hydrocarbyl-substituted amines yields the corresponding mono-
And di-hydrocarbyl substituted chloramines are produced in excellent yields. Reaction of these same chlorinating agents with hydrocarbyl-substituted alkali metal amides or hydrocarbyl-substituted alkaline earth metal amides, in contrast, is not an effective way to prepare hydrocarbyl-substituted chloramines. The reason for this is mainly that it is difficult to obtain hydrocarbyl-substituted alkali metal amides and hydrocarbyl-substituted alkaline earth metal amides. Therefore. It is desirable to react hypochlorous acid or chlorine monoxide with a hydrocarbyl-substituted amine when a hydrocarbyl-substituted chloramine is desired.

Formulas I and I used in the chloramine reaction
The ratio of reaction components of I is not critical and varies within wide limits. The stoichiometric amount of reaction is 1 mole of compound of formula I and 1 mole of compound of formula II. The presence of a slight molar excess of the chlorinating agent of formula II in the reaction mixture may be advantageous.

The chloramine reaction is preferably carried out in an inert, non-aqueous reaction medium. The relative ratio of reaction medium to reaction components is not critical. Generally, the proportion of reaction medium is from about 25 to about 500% by weight of the reaction components of formulas I and II.
Is. Preferably, the reaction medium is miscible with the product chloramine and the tertiary amine to be reacted with chloramine in the subsequent step, but immiscible with water,
This allows the product chloramine to be easily separated from the reaction by-products and water that may form and to the next step,
That is, it can be used without further treatment in the production of the third hydrazinium chloride.

The reaction to produce chloramine can be carried out over a wide temperature range, for example -10 ° C to 150 ° C and at atmospheric pressure, reduced pressure or superatmospheric pressure. The reaction is most conveniently carried out at room temperature and atmospheric pressure. When the reaction is complete, the pressure is reduced to remove unreacted volatiles from the reactor.

The order of addition of the reactants is not critical. Satisfactory results have been obtained by placing the compound of formula I in a reactor containing a non-aqueous inert reaction medium, followed by the addition of the chlorinating agent.

Generally, the reaction is complete within 30-60 minutes. Of course, the amount of reaction components used affects the reaction time. The progress of the reaction can be performed by using an ordinary analytical instrument.
It can be monitored by quantifying the disappearance of reaction components and the appearance of chloramine (formula III). When the reaction is complete,
Chloramine is a common technique from water or water-miscible by-products,
It can be separated for example by distillation, decantation, freezing or by the use of precipitants.

The chloramine produced in this manner is represented by the formula
IV tertiary amines and Sisler et al, Inorganic Synthese
s, Vol. V. Follow the procedure on page 91-95 to react the compound with Formula
To produce the third hydrazinium chloride (reaction B). In this reaction, chloramine is added to a slight excess of a tertiary amine, such as trimethylamine, triethylamine or tripropylamine, at about -20 ° C.
Introduction at a temperature of -40 ° C. The tertiary hydrazinium chloride begins to crystallize as the reactants are mixed together. The reaction is complete within about 30-60 minutes. The reaction mixture is then warmed to room temperature, washed with a suitable solvent (eg kerosene) to remove residual tertiary amine, filtered and dried. The yield of the tertiary hydrazinium salt is quantitative, and the overall yield of the first two steps of this scheme is about 65% or higher based on the amount of compound of formula I.

Tertiary hydrazinium chloride, for example, trimethylhydrazinium chloride, tripropylhydrazinium chloride, tri-n-heptylhydrazinium chloride, dimethylphenylhydrazinium chloride, dimethyl-p-tolylhydrazide. Nitron chloride, cyclohexyldiethylhydrazinium chloride, tripropylmonomethylhydrazinium chloride, and tripropyldimethylhydrazinium chloride are readily prepared using the procedure of Sisler et al.

The reactions to form the chloramine and tertiary hydrazinium salt can be carried out stepwise or simultaneously in a common reactor.

The tertiary hydrazinium chloride thus prepared is treated with an alkali metal amide, an alkaline earth metal amide, a hydrocarbyl-substituted alkali metal amide or a hydrocarbyl-substituted alkaline earth metal amide in the presence of a non-aqueous reaction medium. The reaction for producing anhydrous hydrazine or hydrocarbyl-substituted hydrazine (Reaction C) is carried out according to the method described in US Pat.
No. 6,108.

If desired, a mixture of hydrocarbyl-substituted hydrazines, such as a mixture of monomethylhydrazine and dimethylhydrazine, can be prepared in a conventional reaction and separated by well known techniques such as fractional distillation. This can be achieved as follows. That is, a mixture of mono- and di-methylamines is chlorinated to form a mixture of mono- and di-methylchloramines, which mixture is then treated with a tertiary amine and an alkali metal amide, alkaline earth metal amide, hydrocarbyl substituted alkali. Subsequent reaction with a metal amide or a hydrocarbyl substituted alkaline earth metal amide produces a mixture of the desired products.

The process of the invention can be carried out batchwise or
It can be preferably carried out continuously.

The present invention will now be described with reference to examples.

A. Preparation of Chloramine Example 1 A 1000 ml water jacketed round bottom reactor was equipped with an addition funnel and an efficiency condenser set down for distillation by a connecting tube. The condenser was attached to a 500 ml round bottom receiver cooled to -78 ° C in a dry ice-acetone bath (as convenient for carrying out the method on a laboratory scale). The receiver was connected via a trap and manometer to a water aspirator capable of maintaining a pressure of approximately 25 torr in the reactor. Water at approximately 4 ° C. was circulated from the constant temperature unit through the cooler.

200 ml of ethyl ether was placed in a receiver,
Cooled to -78 ° C. Approximately 325 g of ice, 0.48 mol of monomethylamine (37.2 g of a 40% aqueous solution of monomethylamine, obtained from Aldrich Chemical Co.),
And 0.49 mol sodium hypochlorite (375 ml
Of 1.325 mol of sodium hypochlorite solution, Kuemical
(Obtained from Co.) into a jacketed reactor,
Equimolar amounts of reaction components were prepared. The reactor was closed and the pressure immediately dropped to 25 torr. As soon as the initial gas evolution ceased, the temperature of the water circulating in the reactor jacket was raised to 4
Increased to 0-45 ° C. Methylchloramine was collected in the distillation receiver for approximately 1 hour. The receiver was then separated and the ether solution was decanted into another flask containing anhydrous sodium sulfate as a desiccant.

In the distillation of the product methylchloramine, a significant amount of water is simultaneously distilled and appears as ice in the receiver. Approximately 70 ml of ether was added to the ice remaining in the receiver and warmed until it had completely melted.
After all the ice had melted, the ether layers were combined and dried over anhydrous sodium sulfate. The yield of methylchloramine is
It was 68.7%.

The yield of this reaction, as well as the following Examples 2-8
The yield of the reaction was determined by considering the amount of the tertiary hydrazinium salt produced in the subsequent reaction step (reaction B). Yield determination assumes that chloramines are quantitatively converted to tertiary hydrazinium salts, as reported in the literature. Once the amount of chloramine was determined in this way, the yield was based on the amount of amine reactant used to form chloramine.

Example 2 The procedure of Example 1 is repeated, but instead of monomethylamine, 0.48 mol of dimethylamine (54.0 g of a 40% aqueous solution of dimethylamine, Aldrich Chemical Co.
Dimethylchloramine was prepared using

Example 3 A 100 ml three-necked reactor was equipped with an efficient mechanical stirrer, a subsurface gas inlet tube, a distillation vapor thermometer, and a 20 cm glass condenser set down for distillation. The condenser was connected to a vacuum adapter, and the adapter was connected in series with an oil-filled whisk, a liquid trap containing sulfuric acid, a second oil-filled whisk, and finally with dry ice-acetone oil at -78. Connected to a gas trap cooled to ° C. The adapter was attached to a receiver flask cooled in a dry ice-acetone bath.

A slurry composed of 10 g of calcium hypochlorite in 50 ml of kerosene was placed in a reaction flask. Monomethylamine (0.1 mol) entrained in a stream of nitrogen gas was passed into a wash bottle containing methanol via a gas distribution tube at the bottom of this wash bottle, and via a gas inlet tube, It was fed into the stirred reactor.

The reaction mixture was heated to about 135 ° C. and the product methylchloramine was distilled into a receiver.

Three more runs of this reaction were carried out and the following yields were obtained at the reaction temperatures stated: 27.1%
(50 ° C); 49.2% (72 ° C); 78.2% (11
7 ° C). Absolute temperature is plotted as a function of yield (%), and a linear least squares analysis of the data is performed,
A correction factor of 0.991 was obtained [equation: yield% = (0.
674) (Temperature ° K) -188.7] It is shown that this function is very linear. Thus, increasing the reaction temperature above 135 ° C would further increase the yield.

Example 4 The procedure of Example 3 was repeated, but using dimethylamine (0.1 mol) instead of monomethylamine to prepare dimethylchloramine.

Three more runs of this reaction were carried out and the following yields were obtained at the temperatures indicated: 28.3% (52
C); 49.8% (72C); 79% (117C). The absolute temperature is plotted as a function of yield (%) and a linear least squares analysis is performed to obtain the correction factor [equation:% yield = (0.674) (temperature ° K) -188. .7
From], this function is again very linear.

Therefore, increasing the temperature of this reaction,
It is expected that the yield will increase.

The chlorinating agent of Examples 3 and 4 was not the calcium hypochlorate itself, but the hypochlorous acid formed by the reaction of calcium hypochlorite with methanol, which, upon passage through the wash bottle, the amine. Absorbed by. In a sense, calcium hypochlorite is "activated" by methanol, releasing the chlorinating agent needed for this reaction. The by-product of this reaction is calcium methylate. Hypochlorous acid chlorinates monomethylamine or dimethylamine, optionally forming the corresponding chloramines and water. The water thus formed, from the reaction mixture,
It is effectively removed by momentarily reacting with calcium hypochlorite to form calcium hydroxide, which is easily removed from the reaction mixture. In this way, substantially anhydrous substituted chloramines are obtained for further reaction according to the invention. Other lower alcohols or water can be used instead of methanol in the wash bottle with similar results.

Example 5 An attempt was made to produce methylchloramine by the direct reaction of calcium hypochlorite with monomethylamine, ie without pretreatment of calcium hypochlorite with lower alcohol or water. 0 ° C, 25 ° C or 5
Methylchloramine was not detected at the reaction temperature of 0 ° C.

Considering Examples 3, 4 and 5 together,
The utility of pretreatment of calcium hypochlorite to form hypochlorous acid as a chlorinating agent is demonstrated.

Example 6 A round bottom reactor equipped with a reflux condenser and a pair of gas inlet tubes was charged with 100 ml of a 15% aqueous solution of sodium hypochlorite. The condenser was connected to a T-tube containing carbon tetrachloride. This T-shaped tube has an efficiency gas dispersion tube at the bottom 1
m glass tower. A 10% mixture of monomethylamine in kerosene was charged to the glass column and the glass column was connected to a receiver for collecting the product chloramine.

Carbon dioxide and nitrogen were introduced separately into the round bottom reactor through gas inlet tubes. Carbon dioxide reacts with sodium hypochlorite to form Cl ₂ O as a chlorinating agent. Cl ₂ O was captured by carbon tetrachloride in a T-tube, then passed through a gas dispersion tube and placed in a solution of monomethylamine in kerosene in a glass column. The entire column was covered with a heating tube to raise the temperature of the solution slightly. Warm methylchloramine evolved through the top of the tower and was collected in the receiver.
Methylchloramine was 37.2%.

Example 7 Dimethylchloramine was prepared by repeating the procedure of Example 6 but substituting dimethylamine for monomethylamine. The yield of dimethylchloramine was 36.
It was 6%.

Chlorination of the primary and secondary amines in Examples 6 and 7 co-produces the corresponding chloramines with water, but the water was removed from the reaction mixture by maintaining the receiver at a sufficiently low temperature that the water As it is collected, it is easily removed by freezing it, then separating the desired product.
Alternatively, the desired product is miscible with it, but in a solvent that is immiscible with water, as in Example 1 above,
You can collect. In each case, a substantially anhydrous substituted chloramine is obtained for the subsequent reaction according to the invention.

Example 8 Chloramine: ClNH ₂ was prepared by reacting ammonia (0.1 mol) with chlorine monoxide according to the procedure of Example 6 above. The reaction temperature was 53 ° C.
The yield of chloramine was 27.2%.

B. Production of tertiary hydrazinium chloride 1. Stepwise Preparation Example 9 57 ml of a cold solution of tripropylamine in 100 ml of dry ethyl ether and a solution of methylchloramine in the ethyl ether prepared in Example 1 were added.

The mixture was maintained at about -20 ° C until the crystallization of the tertiary hydrazinium salt appeared complete. The volume of ether was then substantially reduced to promote further crystallization. After filtration and vacuum drying, the yield of dry tripropylmonomethylhydrazinium chloride was approximately 68.7% (determined as the average of 15 experiments) based on the amount of monomethylamine used to make methylchloramine. It was).

Example 10 The procedure of Example 9 was repeated, except that the dimethylchloramine prepared in Example 2 was used instead of chloromethylamine to prepare 1,1,1-tripropyldimethylhydrazinium chloride. The yield of 1,1,1-tripropyldimethylhydrazinium chloride was 65.8% (determined as the average of 16 experiments) based on the amount of dimethylamine used to make dimethylchloramine. .

2. Co-Production with Chloramine Example 11 A gas scrubbing bottle with a gas dispersion tube at the bottom is charged with 100 ml kerosene, 0.1 mol soda amide (4.0 g) and 0.1 mol tripropylamine (14.4 g). did. Chlorine gas (7.1 g) in an amount of 0.1 mol diluted with nitrogen was introduced into the reaction mixture through a dispersion tube.
The reaction was carried out at 0 ° C. for 30-40 minutes. afterwards,
The temperature of the reaction mixture was brought to room temperature and the pressure in the reactor was reduced to remove volatiles. The yield of tripropylhydrazinium chloride containing some sodium chloride is
Similarly, it was 14.8 g.

C. Preparation of anhydrous hydrazine Example 12 The tripropylhydrazinium chloride prepared in Example 11 was reacted with sodaamide to prepare anhydrous hydrazine.

In a 100 ml three-necked reactor, an efficient mechanical stirrer, dropping funnel, subsurface gas inlet tube, distillation vapor thermometer,
And equipped with a 20 cm glass condenser set down for distillation. The condenser was connected in series to an oil bubbler, a liquid trap containing sulfuric acid, a second oil filled bubbler, and finally a gas trap cooled to -78 ° C with a dry ice-acetone bath.

50 ml kerosene (Fisher Scientific Co.), dried by refluxing with sodium metal, and 0.1 mol soda amide (Fisher Scientific C
o.) was heated in a three-necked reactor to 150 ° C. under a gentle stream of nitrogen gas. Heating was continued until no more ammonia was evolved. Approximately 0.1 mole of dry 1,1,1-tripropylhydrazinium chloride was slurried in 20 ml of dry kerosene and placed in the dropping funnel.

The salt slurry was added to the three neck reactor over 10 minutes. White vapor was observed and the vapor temperature increased to approximately 100 ° C. during the salt addition. After about 7 minutes, the formation of white vapor ceased. Reactor temperature is about 16
The temperature was raised to 5 ° C. and the distillation was allowed to proceed for about 30 minutes.

After the distillation, the collected fraction was distilled by a fractionating column to obtain pure anhydrous hydrazine. The yield of anhydrous hydrazine was 39.6% (determined as the average of 3 experiments) based on the initial amount of sodamide used to form chloramine.

Example 13 The procedure of Example 12 is repeated except that 1,1,1-tripropylmethylhydrazinium chloride (prepared as in Example 8) is used instead of 1,1,1-tripropylhydrazinium chloride. Was used to prepare monomethylhydrazine. The yield of monomethylhydrazine was 53.2 based on the amount of amine used to form chloramine.
% (Determined as the average yield of 15 experiments).

Example 14 The procedure of Example 12 is followed, but 1,1,1-tripropyldimethylhydrazinium chloride instead of 1,1,1-tripropylhydrazinium chloride (prepared as in Example 10). Was used to produce UDMH. The yield of UDMH was 56.9% (determined as the average of 16 experiments) based on the amount of amine used to form chloramine.

The hydrazine and hydrocarbyl substituted hydrazines prepared in Examples 12-14 were readily recovered as the anhydrous product and distillation was much less than required in the prior art processes.

The products prepared in Examples 11, 12 and 13 were identified by measuring their boiling points and densities, the measured values being anhydrous hydrazine (bp 113.8 ° C .; d.1.
004), methylhydrazine (bp 87.5 ° C .;
d. 0.874), and UDMH (bp 63.9).
C .; d. 0.791).

The procedure for preparing anhydrous hydrazine described in Examples 11 and 12 produces sodium chloride and tripropylamine as by-products. Tripropylamine is recovered almost quantitatively and can be conveniently recycled to the reaction of the tertiary hydrazinium chloride to produce the starting material. Sodium chloride can be electrolyzed to react with sodium, which reacts with ammonia to form sodamide (which produces 0.5 moles of hydrogen as a byproduct, which can be recovered), and chlorine, which And can be used in a reaction to form chloramine. By proceeding in this way, the operating costs of this method can be significantly reduced. In fact, the alkali metal amides are somewhat regenerated in this way and can therefore be seen somewhat as a capital expense. As mentioned above, this method can be conveniently carried out with soda amide or lithium amide.

Furthermore, the overall process for the preparation of anhydrous hydrazine according to the invention has the most favorable heat balance, approximately 5.
0 × 10 ⁶ kcal / day (values are based on an assumed production of 1000 kg / day of anhydrous hydrazine) (as shown in the heat of reaction table below), which can be used for the generation of process steam.

Reaction heat 2Na + 2NH ₃ → 2NaNH ₂ + H ₂ 1,187,500 KCal / day Cl ₂ + NaNH ₂ → NaCl + ClNH ₂ 1,317,188 〃ClNH ₂ + R ₃ N → R ₃ NCClNH ₂ 531,250 〃 R _{3 NClNH 2 + NH 2 + NaNH 2} → R 3 N + NaCl + N 2 H 4 2,045,312 〃 heat of solution of anhydrous hydrazine in water is a result of the exothermic reaction of _{N 2 H 4 · H 2 O} . Of course, the electrical energy required to produce sodium and chlorine must be considered in determining the overall efficiency of the process, but this requirement depends on the energy available from the combustion of hydrogen generated during the formation of the alkali metal amide. Can be compensated.

Although the above examples for the preparation of hydrocarbyl substituted hydrazines are directed to the preparation of alkyl substituted hydrazines, aryl-, aralkyl- and cycloalkyl-substituted hydrazines can be prepared according to the same general method. For example, aniline, benzylamine or cyclohexylamine can be substituted into the inventor's US Pat.
It can be prepared and reacted with an appropriate tertiary hydrazinium salt as described in 108 to produce the corresponding hydrocarbyl substitution product, ie, phenylhydrazine and the like.

Claims (1)

[Claims] 1. A method for producing chloramine: NH ₂ Cl, which comprises reacting chlorine with soda amide.