DE1964619A1 - Adiabatic process for the preparation of 2,4-dichloro-6-amino-s-triazines - Google Patents

Description

P at «» ι «» ** "■ · - _λΙΜ 7X-297O / GC 352

8 Mönchen 2, Bräuhauisfraße 4 / HI

Adiabatic process for the production of ZjA-dichloro-e-aminO-

s-triazines

The present invention relates to a hitherto uncommon and extremely fast process for the preparation of 2,4-dichloro-6-monosubstituted-amino-s-triazines from very high purity and in high yields according to a method which.Cyanuric chloride with a sterically unhindered primary Amine is implemented, this reaction under adiabatic loading _ .. conditions and for a relatively short period of time in one ™ two-phase organic-aqueous medium going on.

The products produced by this process, ie the "2,4-dichloro-6-moiio-.subst. -Amino-s-triazines, represent intermediates which are used for the production of diamino-chloro-s-triazines, which in turn serve to prevent unwanted plant growth and unwanted vegetation and are therefore of extremely great value and of great economic importance as herbicides. isopropylamino-s-triazine), PrOpazine (2-chloro-4,6-bis-isopropylamino ⁱ -s-triazine) etc. These diamino compounds can be used both as selective herbicides for weed control in cultivated plants and as soil sterilizers for the total suppression of unwanted plants will.

The conversion of the 2,4-dichloro-6-mono-subst-amino-s-triazines obtained according to the invention to the aforementioned economically important diamino compounds takes place by conversion with an equivalent amount of the same or a different primary or a secondary amine. So one sets the according to the invention obtained products, i.e. the 2,4-dichloro-6-mono-substituted-amino-s-triazines with amines, such as ethylamine, isopropylamine and the like, in order to achieve the above-mentioned economically valuable

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to obtain full diamino compounds.

A typical embodiment of the present invention: - consists in the reaction of cyanuric chloride under adiabatic conditions in a biphasic organic-aqueous medium, with a sterically unhindered primary amine, for example isopropylamine, for example, 2,4-dichloro-6-isopropylamino-s-triazine to obtain.

The 2,4-dichloro-mono-subst, -amino-s-triazines are well-known Compounds are and are usually made by reacting cyanuric chloride with primary amines at low temperatures and in the presence of a solvent. When using this procedure, it is necessary according to the literature that the Reaction to neutralize hydrochloric acid (HCl) formed, namely either (1) with an excess of the converted amine or (2) with an acid-binding agent such as sodium hydroxide, sodium carbonate and the same. The neutralization of the HCl is made more difficult by using excess amine or an acid-binding agent the separation of the desired amino-s-triazine, of course, and is also undesirable from an economic point of view. If you have the If hydrochloric acid is not neutralized, the yields are significantly lower on the desired amino-s-triazine. Another alternative to nitrating or removing hydrochloric acid is to use it a distillation process using high temperatures. This approach is also not recommended because it relies on this Way another stage in the manufacturing process of the desired Amino-s-triazine is introduced. =

The US patent 3,328,399 describes a process for the preparation of amino-s-triazines without neutralizing the in the Reaction formed HCl. However, this patent only relates to the implementation of cyanuric chloride with secondary amines in one anhydrous system where the hydrochloric acid formed is distilled off from the reaction mixture. ■

Furthermore, earlier experimental work has shown that when methyl or ethylamine hydrochlorides are reacted with Cyanuric chloride in an anhydrous system, the reaction only with extremely high temperatures of 200 ° C and higher. In addition to the desired 2,4-dichloro-6-mono- <subst. -

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amino-s-triazine has a large amount of unknown and undesirable by-products. "~ '- * "-''* · · ' - ■■■■ '■■■ "■.

: _{ί ;;} According to the invention, 2, ^ - dichloro-ö-mono-subst. -amlrio-striazine ... in high yield and of extremely high purity and _k in, sejar a short time obtained by reacting cyanuric chloride under adiabatic conditions in a two-phase organic aqueous "tledium" with a sterically unhindered primary amine. In this way simultaneous formation of reduced minimum of unerwüfischteri by-products a to-and most practically completely ^prevented;; which is the desired resulting monoamino-dichloro ^r ti: iazin can "are then further reacted to the commercially important * Diamitto-chlör-s-triazineTi, which products are characterized by their herbicidal effect. ·

. The recation between cyanuric chloride and the aforementioned sterically unhindered amine is carried out in a two-phase organic-aqueous medium under adiabatic conditions.

The present inventive method brings some important advantages. -amino-s-triazines once the process is extremely quick and the desired 2,4-dichloro-6-mono-substituted-amino-s-triazine is obtained within a few minutes, sometimes even within a period of 1 -2 minutes. In addition, the products obtained are of extraordinary purity, ie a purity of about 99 % and this with yields of up to 99.67 ». When using the | Process, by-products are only obtained in very small quantities, so that it is no longer necessary to separate these by-products using expensive and complicated processes.

..--. _; . According to a preferred embodiment of the present invention is reacted with a sterically ungehincferten primary amine under adiabatic conditions in a biphasic organic-aqueous medium cyanuric chloride to _2,4-t bichlor-6-amino-s-triazine of ausserördentlich high purity and in very good To obtain yields. The reaction proceeds at an extraordinarily high rate and is complete within a few minutes , usually within 1-2 minutes.

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products are characterized by a purity of around 99% and the The yields obtained are up to 99.6%.

The 2,4-DiChIOr-O-IHOnO-SUbSt. -amino-s-triazine, which nac the process according to the invention can be produced by the following formula can be represented: =

Cl / N ~ ^C1

N
N

NHR

In this formula means

.R is a lower alkyl, lower alkenyl or a cycloalkyl radical of up to 6 carbon atoms.

Typical examples of alkyl groups are as follows: Propyl, isopropyl, butyl, isobutyl, amyl, hexyl, and the like; as alkenyl groups, mentionable are: propenyl, butenyl, etc .; as representatives of cycloalkyl groups are cyclopropyl, Cyclobutyl, called cyclohexyl.

The sterically unhindered primary amine corresponds to the formula RNH «, in which R has the meanings given above.

A particularly important embodiment of the process according to the invention is the preparation of Zj ^ -Dichlor-o-isopropylamino-s-triazine by reacting cyanuric chloride with isopropylamine under adiabatic conditions in a two-phase organic aqueous medium. Preferably, the cyanuric chloride of the mixture is in an inert organic solvent added. But also do not obstruct the course of the reaction or adversely affect the choice of solvent is not only inert, ie non-reactive _s. Furthermore, the requirement is that the solvent can be dried easily. Suitable solvents for this purpose are: toluene, benzene, xylene acetone _{9 s} Methyläthy ketone, etc.

As acid-binding agents, which in the present process can be used are to be mentioned: the converted amine

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e? - · - IQC / CIQ

.self, alkali metal hydroxides, alkali metal carbonates and the like. As alkali metal acid binders, for example, sodium · hydroxide, sodium carbonate, potassium! ./oxide, potassium carbonate, etc.

thinks. As a rule, aqueous solutions of such alkali metal acid binders are used used, usually a 50% sodium hydroxide solution, although of course solutions which are more or less than Contains 50% of the selected alkali metal acid binder, can be used

are. "-.- ■ - ■■

As a rule, stoichiometric amounts of the reactants are used, i.e. about 1 mole of amine, about 1 mole Cyanuric chloride, and about 1 mole of alkali metal acid binders. But when ' the amine itself is used as an acid-binding agent of course about 2 moles of this amine per mole of cyanuric chloride are used to be brought.

In one embodiment of the invention, cyanuric chloride and isopropylamine become continuous under adiabatic conditions in one working reactor brought to implementation. So can e.g. water, a 50% sodium hydroxide solution and isopropylamine mixed in a mixing tank and the mixture on top of that continuously working reactor. Simultaneously with the addition of this mixture to the reactor, a solution of cyanuric chloride in toluene is supplied to the reactor and the reaction takes place the desired in a relatively short period of time of 1 - 2 minutes 2,4-dichloro-6-mono-subst-amiho-s-triazine. The implementation runs continuously, i.e. the reactants become practical continuously fed to the reactor and the desired 2,4-dichloro-6-mono-substituted-amino-s-triazine is withdrawn practically continuously from the reactor.

As already mentioned above, the reaction gives the desired 2,4-dichloro-6-mono-substituted-amino-s-triazine in an extraordinary way a short time of a few minutes, i.e. within 1 - 2 minutes. Of the The reactor used in this process is a continuous ar-. widening of small volume, · into one;

the reactants are let in fairly quickly in such a reactor * the implementation takes place in a very short time and the tfünschteri Products are then withdrawn from the reactor. That's why Is it possible when using such a reactor that

Α AAA Λ I ¹ * I Λ Λ Λ Λ -._ '': "..-.-"

■ Continuous settlement under adiabatic conditions ten and obtain the desired product in a very short time; With this procedure, the reaction is so powerful ™ - ·. capable of producing large volumes of the desired product «,

A continuous reactor can be used for the production of a 2 _> 4-dichloro-6-mono-subs. ~ Amino-s-triazine by reacting cyanuric chloride with isopropylamine, which is also the acid-binding agent, under adiabatic conditions. Water, isopropylamine and toluene, which contains the cyanuric chloride to be converted in dissolved form, are introduced into the continuous reactor, which has a volume of 7.5 liters. The flow rates from the various lines are regulated so that practically stoichiometric amounts of the various reaction components are reacted. Monitoring the mutual amounts of cyanuric chloride and isopropylamine is particularly important in order to ensure the formation of the desired 2,4-dichloro-6-isopropylamino-s-triazine. The reaction is complete after about 1-2 minutes. The 2,4-dichloro-6-monosubst.-amino-s-triazine is brought through a decanter and then further into the atrazine reactor, where it is converted into the end product 2-chloro-4-ethylamino-6-isopropylamino-s -triazine to be transferred. The by-products of the reaction pass from the decanter into a separator. -.

In modification of the method, a water stream, a sodium hydroxide stream and a stream of isopropylamine is introduced into a mix tank. The aforementioned materials are in this mixing tank premixed and this mixture then together with a toluene stream, which contains the cyanuric chloride dissolved, introduced into the continuous reactor. The formed desired product 2,4-dichloro-6-isopropylamino-s-triazine passes from the reactor to the decanter and then on to the atrazine reactor. the Quantities of the various material inflows are set in such a way that that practically stoichiometric amounts of the various components for

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Implementation succeed. The review of the mutual quantitative proportions cyanuric chloride, isopropylamine and sodium hydroxide (or any other alkali metal hydroxide or alkali metal carbonate than Acid binder) is important to the formation of the desired 2,4-dichloro intermediate and finally the desired diamino product to ensure high yield and purity.

The following examples serve to illustrate the method according to the invention.

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example 1

A solution of 29.6 g is added to a solution of 92.2 g (0.5 mol) of cyanuric chloride in 500 toluene at 24 ° C., which is located in a four-necked round bottom flask equipped with a dropping funnel, stirrer, condenser and thermometer (0.5 mol) isopropylamine and 20.0 (0.5 mol) sodium hydroxide and 500 g of water at 24 ° C. were added over a period of 10 seconds with stirring. The temperature of the reaction mixture increases in less than 30 seconds at 80 ⁰ C. After exactly one minute the gc, analysis showed the final product 99.8% 2,4-dichloro-6-isopropylamino-s-triazine, 0.2% 2 , 4-ice-isoprOpylamino-6-chloro-s-triazine and traces of cyanuric chloride.

Example 2

26.8 kg per hour (1 mole) of isopropylamine, 37.2 kg per hour (1.02 mole) of 50% sodium hydroxide solution and 163 kg per hour of water were poured into a mixed tariff from different lines and the resulting mixture was simultaneously with 558 kg per hour of 15% strength cyanuric chloride solution in toluene in a continuously operating reactor with a volume of 4.15 liters and allowed to flow through. The reaction was started at a temperature of 31 ° C under adiabatic conditions, the effluent temperature was 80 ⁰ C. After analysis it was established that the frame conversion to 99.5% passed, and a yield of 98.5%, to 99.0% pure 2 , ^ - dichloro-o-isopropylamino-s-triazine was achieved.

Example 3 _ '* _

The reactants were charged into a 7.5 liter continuous reactor at a rate of 53 "6 kg per hour of isopropylamine (2.0 moles), 174 kg per hour of water, and 558 kg per hour of 15 percent cyanuric chloride solution in toluene - and let it run through. The temperature at the inlet was 30 ⁰ C and at the outlet 80 ° C. The conversion was 99.5%; the yield of 99.0% pure 2,4-dichloro-6-isopropylamino-s-triazine was 99.5%.

Of course, various changes can be made to the procedures described above can be carried out.

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Claims (10)

Claims Iy process for the preparation of ^, ^ - Dichlbr-ö-mono-subst. amino-s-triazines of the formula wor in R is a lower alkyl or alkenyl group or a cyclo, alkyl radical means characterized in that a sterically unhindered primary Am in the formula RNH ^, wherein R has the meanings given above, with cyanuric chloride under adiabatic conditions during
a relatively short period of time in a two-phase organic-aqueous medium. 2. The method according to claim 1, characterized in that the reaction is carried out in the presence of a basic alkali metal compound as an acid-binding agent. 3. A process according to claim 1, characterized in that one carries out the reaction at a temperature between 0 ° and 1OQ ⁰ C, preferably between 30 ° C and 86 ^P. 4. The method according to claim 1, characterized in that one practically stoichiometric amounts of the reactants for Implementation used. ..— »". 5. The method according to claim 1, characterized in that the cyanuric chloride, dissolved in an inert organic solvent, adding to the reaction mixture. 6. The method according to claim 5, characterized in that the solvent used is toluene _? Benzene, xylene, acetone or Methyläthylketoii used, nnqη% γ- ' 7. The method according to claim 2, characterized in that - the amine is first mixed with the acid-binding agent and -, then reacts with the cyanuric chloride. 8. Procedure according to. Claim 2, characterized in that an alkali metal hydroxide or an alkali metal carbonate is used as the acid-binding agent. 9. The method according to claim 1 for the preparation of 2,4-dichloro 6-isopropylamino-s-triazine, characterized in that a solution of cyanuric chloride in toluene with isopropylamine in a two-phase organic-aqueous medium, which is an alkali metal hydroxide or contains an alkali metal carbonate as an acid-binding agent, to "implement. 10. '■ = Method according to claim 9, characterized in that sodium hydroxide is used as the alkali metal hydroxide. Ho method according to claims 9 and 10, characterized in that that isopropylamine, sodium hydroxide and water are first mixed together and this mixture is then mixed with cyanuric chloride implements. 12 "The method according to claim 9, characterized in that one uses stoichiometric amounts of the reactants. Jk / aw / 2.12.69i 009827/20 ^ 2