DE2429958A1 - PROCESS FOR THE PREPARATION OF DINITROANILINE HERBICIDES - Google Patents

Description

The invention relates to a method of manufacture
certain 2,6-dinitroaniline herbicides. It also relates to certain N-alkylated aniline intermediates which are useful in the process and which are novel compounds and to a process for the preparation of such N-alkylated aniline intermediates. Finally, the invention relates to a process for N-alkylating
aromatic amines with the formation of compounds which are suitable for the nitration processes mentioned.

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As already mentioned, the invention relates primarily to a process for the preparation of N-alkylated and N, N-dialkylated ones 2,6-Dinitroanilines, which are suitable as herbicidal agents.

The N-alkylated and N _f N-dialkylated 2,6-dinitroaniline compounds which are obtained by the process according to the invention correspond to the following general formula I

O ₈ H

I li "■

(I)

in the -

Y is an alkyl group with 1-4 carbon atoms, a halogen atom or a trifluoromethyl group,

Z represents a hydrogen atom, a halogen atom, an alkyl group with 1-4 carbon atoms, an alkoxy group with 1-4 carbon atoms or a monosubstituted alkyl group substituted by a halogen atom or an alkoxy group has 1-4 carbon atoms,

R _{1 is} a straight-chain or preferably branched alkyl group with 1-6 carbon atoms, a cycloalkyl group with 4-6 carbon atoms, a monohaloalkyl group with 1-4 carbon atoms or an alkoxyalkyl group, the alkyl part of which has 1-4 carbon atoms and the alkoxy part of which has 1 to 4 carbon atoms and

R- denotes a hydrogen atom or one of the groups R ₁ .

Examples of straight-chain and branched alkyl substituents are methyl, ethyl, N-propyl, isopropyl, N-butyl, tert-butyl, n-pentyl, n-hexyl, 2-pentyl, 3-pentyl, sec-butyl, 1-ethylpropyl groups and the like.

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Examples of cycloalkyl groups are cyclobutyl, cyclopentyl and cyclohexyl groups.

Examples of halogen substituents are fluorine, chlorine, bromine and iodine atoms.

The preparation of the compounds of general formula I has traditionally been accomplished by nucleophilic displacement reaction between the appropriately substituted 2 _r 6-dinitro-1-halobenzene and the appropriately substituted amine. The displacement reaction was brought about by heating the reactants to a temperature between 50 and 150 ^° C., which was preferably carried out in an aromatic solvent.

The preparation of N-alkylated 2,6-dinitroanilines of the general Formula I with high yield by nitrating N-alkylated anilines is not described in the prior art been. The known process for the preparation of tertiary 2,6-dinitroanilines, in which two substituents of the nitrogen atom represent haloalkyl groups, include nitriding with at least one five-fold excess of nitric acid, which at the beginning of the reaction in a concentration of 50% to 90% and in is present in such an amount that the acid concentration by the end of the reaction is 50%, the reaction carried out in the presence of a catalytic amount of nitrous acid or a nitrite ion-forming material will.

The nitration of the N-alkylated secondary anilines in the 2- and 6-positions in high yield without the prior hydrogen atom present on nitrogen ζ. B. by acetylation is blocked, is due to this prior art

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not to be expected.

The invention now provides a safe and effective method for converting the corresponding N-alkylated ones Anilines, especially the compounds of the general formula II

R ₂

in which R ₁ , R _2, Y and Z have the meanings given above with regard to general formula I and W and V denote hydrogen atoms or nitro groups, with the proviso that W and V do not simultaneously represent nitro groups, into the N-alkylated 2,6 -D.initroanilineverbindungen of the general formula I. In the process according to the invention, a compound of the general formula I is nitrated using the nitriding composition defined below and having three components and thereby in high yield to a mixture of a compound of the general formula I and, if the Group R, which means a hydrogen atom, is converted to the N-nitroso-N-alkylated 2,6-dinitroaniline. According to the most preferred embodiment of this process, the nitration mixture, in those cases in which it is necessary, is reacted further with a denitrosating agent in order to convert the N-nitrosone by-product into the corresponding compound of the general formula I.

The nitrating agents used in the process according to the invention can be represented graphically by a trapezoid, whose area is defined by lines that define the points

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connect which have the following meanings: 60% HNO ₃ , 8% H ₂ SO ₄ , 32% H ₂ O; 50% HNO ₃ , 35 t H ₃ SO ₄ , 15% H ₃ O; 2% HNO ₃ , 68% H ₃ SO ₄ ; 30% H ₂ O and 2% HNO ₃ , 20% H ₃ SO ₄ , 78% H ₃ O. Each of these values represents a real weight percentage.

The preferred three-component nitriding compositions fall into a trapezoid, the area of which is formed by lines connecting points corresponding to the following meanings: 45% HNO ₃ , 19% H ₃ SO ₄ , 36% H ₃ O; 45% HNO ₃ , 36% H ₃ SO ₄ , 19% H ₃ O; 20% HNO ₃ , 52% H ₃ SO ₄ , 28% H ₂ O and 20% HNO ₃ , 27% H ₃ SO ₄ , 53% H ₃ O. Each of these values represents a real weight percentage.

The optimal number of moles of nitric acid per mole the compound of the general formula II is used depends on the compound to be nitrated and the composition of the nitrating agent used. In general, the compounds of general formula II in the W and V represent hydrogen atoms, preferably in the Way nitrated that one uses 2.2 to 5.0 moles of nitric acid per mole of N-alkylated aniline. Within this mash- = th range is the range that extends from 2.5 to 3.5 moles of nitric acid per mole of N * -alkylated aniline, generally more preferred. When W or V represents a nitro group, it is preferred to be 1.2 to 4.0 moles of nitric acid to use per mole of N-alkylated aniline. The narrower range of 1.5-2.5 moles of nitric acid is within this range generally more preferred.

The molar ratio of sulfuric acid to N-alkylated aniline, which is used in the nitriding process according to the invention extends advantageously from 1.5: 1 to 15.0: 1, more preferably from 2.0: 1 to 10.0: 1. On a weight percent basis These ranges correspond to about 30 to 70% for sulfuric acid, preferably about 35% to

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It has been shown that the amount of water present in the nitriding mixture is an essential factor according to the invention and is related to the optimum temperature. In general, reaction mixtures containing a higher percentage of haters require higher reaction temperatures. The amount of water in the nitriding mixture used as the starting material should make up about 15% to about 78% of the weight of the nitriding mixture. A sufficiently high temperature should be used to convert any N-alkylated mononitroanilines to the N-alkylated 2,6-dinitroanilines. It has been shown that the compounds of the general formula II ^{can be nitrated at temperatures from 0 to 70 °} C., but temperatures below about 15 ^° C. prevent the complete course of the dinitration and are therefore not particularly preferred. Temperatures above 70 ^° C. are not desired, since the reaction becomes too difficult to control. The reaction is exothermic and cooling is generally required to keep the temperature below the upper limit and desirably within the optimum range. The optimum temperature depends on the N-alkylated aniline used as the starting material and the composition of the nitrating agent. The generally preferred range for the reaction temperature extends from. about 35 ⁰ C to about 60 ⁰ C.

When the process is in a range of 0 ⁰ C to 70 ⁰ C. (Preferably 35 ° C to 60 ⁰ C) is carried out, the nitriding with the mixed acid can be controlled easily. It has been found that the nitration with concentrated nitric acid must be carried out below 10 ° C., otherwise an uncontrolled reaction occurs. Because of the relatively simple control required for the mixed acids, this Syetera requires one

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much lower cooling capacity. If there are power failures or restrictions, the mixed Acid nitration used can be easily handled while using concentrated nitric acid would likely set an explosion.

Another feature of mixed acid nitration is the small excess (0.50 to 1.50 mol) of nitric acid that is used for Termination of the reaction is required. When using concentrated nitric acid, at least 5 to 10 moles are required necessary. The costs and potential hazards associated with concentrated nitric acid are significant greater than in the case of the mixed acid in which the recovery the nitric acid is not essential for the economics of the process.

According to the invention, the N-alkylated aniline can be in the form of a Liquid, a solid or in the form of a solution in an inert solvent such as ethylene dichloride, Chloroform, carbon tetrachloride or nitromethane can be reacted with the nitrating solution. For the practical Implementation of the method according to the invention is a must proved to be preferred, a solution of the N-alkylated aniline to use in ethylene dichloride, the ratio of ethylene dichloride in ml to the compound of the general Formula II in g ranges from about 3.0: 1 to about 0.5: 1, preferably 0.75: 1.

The addition is not a critical factor. Dependent on Depending on the particular situation, one can either add the nitrating agent to the compound used as the starting material of the general formula I or add the compound of the general formula II to the nitrating agent.

The product of the general formula I can be isolated after the nitration reaction has ended. The termination of the

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The reaction is followed using conventional methods such as thin layer chromatography or NMR spectroscopy. It has been found, however, that in the case of the compounds of the general formula II in which R _{2 is} a hydrogen atom, it is advantageous to add a denitrosating agent, preferably a combination of concentrated hydrochloric acid and sulfamic acid, to the reaction mixture obtained in the nitration stage treat. This last-mentioned step is particularly important, since this treatment leads to an increase in the product yields by approximately the amount of the N-nitroso by-product of the general formula III present

(III)

in which R ₁ , V, W, Y, Z have the meanings given above, leads. it has been found that the molar ratios of hydrochloric acid and sulphamic acid to the moles of the N-nitroso compound present should in each case be at least 1: 1. Preferably the molar ratio of hydrochloric acid to N-nitroso compound should be about 5: 1 to 1.5: 1. A molar ratio of sulfamic acid to N-nitroso compound of 2: 1 is preferably used. The temperature of the Denitrosierungsstufe may extend from 20 * C to 100 ⁰ C and should preferably be between 80 and 100 ⁰ C. Although the denitrosation step can be carried out at atmospheric pressure, it is preferred to carry out this step under pressure in order to retain the hydrochloric acid.

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Other denitrosants such as hydrochloric acid and ferrous chloride, can be used, although the use of hydrochloric acid and sulfamic acid is preferred.

While the process according to the invention is usually carried out batchwise, it is also carried out continuously Method within the scope of the invention.

Examples of compounds that can be readily prepared by the process of the present invention include z. B. a: N- (isopropyl) -3,4-dimethyl-2,6-dinitroaniline, N-n-propyl-3,4-dimethyl-2,6-dinitroaniline, N-cyclohexyl-3,4-dimethyl-2,6-dinitroaniline, N- (2-butyl) -3,4-dimethyl-2,6-dinitroaniline, N-Cyclopentyl-3,4-dimethy1-2,6-dinitroaniline, N-cyclobutyl-3,4-dimethyl-2,6-dinitroaniline, N- (2-butyl) -3-isopropyl-4-methyl-2,6-dinitroaniline, N- (2-butyl) -4-t-butyl-2,6-dinitroaniline, N- (2-amyl) -3-sec-butyl-4-methyl-2,6-dinitroaniline, N-isopropyl-3,4-d, iethyl-2,6-dinitroaniline, N-3-pentyl-3,4-diethyl-2,6-dinitroaniline, N- (2-butyl) -3-chloro-4-methyl-2,6-dinitroaniline, N- (2-butyl) -3- methoxy-4-methyl-2,6-dinitroaniline, N- (1-ethylpropyl) -3,4-dimethyl-2,6-dinitroaniline.

The 3,4-diethyl, 3-methyl-4-ethyl, 3-ethyl-4-methyl, 3-ethyl-4-propyl-, 3,4-diisopropyl-, 3,4-di-n-propyl-, 3,4-di-n-butyl, 3,4-diisobutyl, 3-propyl-4-butyl and 3-methyl-4-isopropyl derivatives of the above-mentioned 2,6-dinitroanilines obtained in a similar manner by the above process using the corresponding 3,4-disubstituted N-substituted anilines.

Examples of compounds in which the group Y is a trifluoromethyl group represents are: N-n-Propy.l-3-methyl-2/6-dinitro-4- (trifluoromethyl) -aniline, N-sec-butyl-3-methyl-2,6-dinitro-4- (trifluoromethyl) aniline, 3-methyl-2,6-dinitro-N-3-pentyl-4- (trifluoromethyl) aniline and 3-ethyl-2,6-dinitro-N-isopropyl-4- (trifluoromethyl) aniline.

4 0988371416

Representative representatives of tertiary 2,6-dinitroanilines which can be prepared by the process of the invention include, for example: N-methyl-N- (2-chloroethyI) -3,4-dimethyl-2,6-dinitroaniline, N, N -Di- (n-propyl) - oi _t oc _r oc, -trifluoro-2,6-dinitro-p-toluidine, N-ethyl-N-butyl- CC, oC, oC -trifluoro-2,6-dinitro- p-toluidine, N, N-di (n-propyl) -3,4-dimethyl-2,6-dinitroaniline, N, N-dimethyl-3,4-dimethyl-2,6-dinitroaniline _f N, N-diethyl -3,4-dimethyl-2,6-dinitroaniline, N-ethyl-N-butyl-3,4-dimethyl-2,6-dinitroaniline ,. N-methyl-N-cyclhexyl-3,4-dimethyl-2,6-dinitroaniline, N, N-diethyl-4-chloro-3-methyl-2,6-dinitroaniline , N, N-dibutyl-3,4- dimethy1-2 _# 6-dinitroaniline, N, N-di (n-propyl) -4-cKbr-3-methyl-2,6-dinitroaniline, N, N-di (n-propyl) -3-chloro-4- methy1-2,6-dinitroaniline, N, N-dimethyl-3-methyl-4-chloro-2,6-dinitroaniline, N-methyl-N-ethyl-3,4-dimethyl-2,6-dinitroaniline, N, N-dimethyl-3,4-dimethyl- ^ ⁴ , <X ⁴ , oc ⁴ -trifluoro-2,6-dinitroaniline, N, N-diethyl-3-chloro-4-methyl-2,6-

trifluoro-2,6-dinitroaniline, N, N-di (n-propyl) -3-methoxy-4-methy 1-2,6-dinitroaniline, », N-diethyl-S ^ -dimethyl-C * ⁴ - _f

oC ⁴ , 06 ⁴ -trifluoro-2,6-dinitroaniline, N, N-diethyl-3-methoxy-4-methyl-2,6-dinitroaniline, N, N-di (n-propyl) -3-ethoxy-4 -methyl-2,6-dinitroaniline, N, N-di (n-propyl) -3-butoxy-4-methyl-2,6-dinitroaniline, N, N-bis (2-chloroethyl) -3,4-dimethyl -2,6-dinitroaniline and N, N-bis (2-chloroethyl) -4-methyl-2,6-dinitroaniline.

Some preferred methods have been used to make the preferred Dinitroanilines are given below.

In a preferred process for nitrating N- (1-ethylpropyl) -3,4-dimethylaniline, the nitrating agent used has a water content of about 35 to 53 percent by weight, the aniline compound being reacted in an amount such that a molar ratio of nitric acid to it the aniline of about 3.25-1 and a mol ratio of sulfuric acid to the aniline compound of about 2.25-1 result. The reaction is carried out in the Heise,

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that one keeps the temperature of the reaction mixture at about 35 ⁰ C to 70 ° C. The reactants are mixed for about 2 hours, the temperature of the reaction mixture being maintained at about 35 ^° C. to about 70 ^° C. for about 1 hour after the mixing is complete. Subsequently, the denitrosation is effected by addition of hydrochloric acid and sulfamic acid to the mixture being maintained for about 1 to 6 hours a temperature of 70 ⁰ C to 100 ⁰ C and then the formed N- (1-ethylpropyl) -2,6-dinitro -3,4-dimethylaniline product isolated.

The method is preferably carried out in ethylene dichloride as the solvent and is further characterized by that the solvent ratio, expressed in ml of ethylene dichloride per g of N- (1-ethylpropyl) -3,4-dimethylaniline ranges from about 3.0: 1.0 to 0.5: 1.0, more preferably 0.75: 1.0.

A preferred embodiment, de s ^a method for nitration of N- (2-butyl) -3,4-dimethylaniline according to the nitrating agent has a water content of about 40 to 53 wt .-%, and the aniline compound is reacted in an amount such that give a molar ratio of nitric acid to the aniline compound of about 3.25: 1 and a molar ratio of sulfuric acid to the aniline compound of about 2.25: 1 and wherein the temperature of the reaction mixture during which the reactants are mixed over the course of about 2 hours at about 50 ^° C. to 70 ^° C., after which the temperature of the reaction mixture is maintained at about 50 ^° C. to about 70 ^° C. for about 1 hour after the mixing is complete. The denitrosation of the mixture is effected by addition of hydrochloric acid and sulfamic acid, maintaining a temperature of 70 ⁰ C to 100 ⁰ C for a period of 1 to 6 hours and recovering the N- thus formed (2-butyl) -2, 6-dinitro- 3,4-dimethylaniline product

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tes.

The process is preferably carried out in ethylene dichloride as the solvent, and is further characterized in that the solvent ratio is expressed in ml of ethylene dichloride per g of N- (2-butyl) -3,4-dimethylaniline, ranges from about 3.0: 1 to about 0.5: 1, more preferably from 0.75: 1.

Let the method of the present invention be carried out by the following Examples 1 to 38 further explained. In any case, the parts and percentages are, unless otherwise stated, based on weight. In all cases, the end product is isolated by thin layer chromatography and thoroughly tested Identified ultraviolet absorption spectroscopy.

Mononitro-N-alkyl-3,4-xylidines

The invention also relates to certain new N-alkyl-3,4-xylidines and their direct or post-nitration use as herbicides. It also concerns a process for their preparation and their nitration. The new compounds correspond to the following general formula IV

(IV)

CH ₃

in the

R _{1 is} a branched-chain alkyl group with 4 or 5 carbon atoms selected from / sec. -Bu ty! Group, the 1-ethylbutyl group uni · 1-ethylpropyl group

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Group and

Rj and R ₃ denote hydrogen atoms and nitro groups, with the proviso that the groups R ~ and R * do not represent nitro groups on the same side. ..,.

As mentioned above, the invention also relates to the use of certain compounds of the general formula IV, namely the mononitro compounds, to control undesirable Plant species. They can be used to treat a wide variety of undesirable monocotyledons and dicotyledons Combat plants. The compounds show both pre-emergence and post-emergence herbicidal activity and can affect the foliage of the unwanted plant or applied to the soil containing the seeds of the plant preferably, solid or liquid formulations used conventional horticultural adjuvants or formulation auxiliaries, such as dispersants or contain surfactants.

Accordingly, there is the weed control method of the present invention therein, a herbicidally effective amount of a compound of the general formula I, in which the groups R- or R, Nitro groups represent, on the foliage of the undesirable To apply plant species or the soil containing the seeds of undesirable plant species. The control or Control is usually achieved by having a or applies multiple active ingredients in an amount of about 1.12 to 28.0 kg / ha (1-25 pounds per acre).

The solid formulations to be used include dusts. Dust concentrates and granulate products. For application in liquid form, the product is usually first to Processed a wettable powder that contains about 25 to 95% by weight of the active ingredient, about 4 to 70% by weight of a fine distributed diluents, such as kaolin, attapulgite clay, Silicon dioxide, pumice stone, talc or diatomaceous earth, and

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about 1 to 5% by weight of a dispersant such as an alkali metal salt of a naphthalenesulfonic acid, an alkali metal lignosulfonate or the like. The wording can also contain about 1 to 5% by weight of a surface-active agent, such as sodium N-methyl-N-oleoyl taurate, alkylphenoxypolyoxyethylene ethanol, sorbitan fatty acid ester or the like. The wettable powder is usually before his Application as a liquid spray dispersed in water.

In addition to and more importantly than their direct use as herbicides, the new compounds of the general formula IV have unexpectedly advantageous suitability as Intermediates for the preparation of dinitroanilines of the general formula I, such as N-sec-butyl-2,6-dinitro-3,4-xylidine, N- (1-ethylpropyl> -2,6-dinitro-3,4-xylidine and N- (1- »ethylbutyl) -2,6-dinitro-3,4-xylidine.

It is already known to use these dinitro compounds to produce nucleophilic displacement reaction at the 1-position of a 2,6-dinitro-3,4-xylene substituted in the 1-position, for example an arain being used to to replace a 1-Chloratora.

In the method according to the invention are in the ortho position introduced nitro groups to an N-alkyl group, a 3,4-xylidine. This heg leads to various unexpected Benefits.

The first advantage is the easy accessibility of the starting materials. In any case, one uses as Starting material o-xylene, which is either nitrated or chlorinated. In one case you get a mixture of 3-nitro-o-xylene and 4-nitro-o-xylene, while in the other Case a mixture of 3-chloro-o-xylene and 4-chloro-o-xylene is formed. In the case of the nitro compounds, the

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Ring isomers are easily separated using conventional distillation equipment, whereas the separation of the 4-chloro-o-xylene of the ring isomer of this compound can only be achieved by distillation with great difficulty because the boiling points of the isomers are very close to one another. The second advantage of the method according to the invention consists in that the N-alkylamino substituent present in the 4-position of the o-xylene ring system with respect to the The nitration reaction is strongly ortho-directing, which is in contrast to the corresponding 4-chloro compound, which causes an equal substitution in the meta position. This disadvantage is compounded by the fact that part of the 3,4-dimethyl-2, β-dinitrochlorobenzene formed forms a eutectic mixture with the ring isomers of this compound, so that the yield of the desired compound obtained by fractional crystallization continues is decreased.

Accordingly, the invention & ß another method for Preparation of compounds of the general formula V.

(V)

in the

Typically a branched-chain alkyl group with 4 or 5 carbon atoms, selected from those comprising the sec-butyl group, the 1-methylbutyl group and the 1-ethylpropyl group Group,

R ₄ and R ₅ denote hydrogen atoms or nitro groups, with the proviso that the groups R and R _{5 are} not simultaneously

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Represent hydrogen atoms, provided that is characterized in that one is a compound of the general Formula IV is reacted with concentrated nitric acid.

If it is desired to prepare N-alkyl-2,6-dinitro-3,4-xylidine from the non-nitrated xylidines, nitration can be accomplished in a single step by reacting the xylidine with 5 to 20 moles of HNO ₃ . Alternatively, the nitration can be carried out in two stages by first forming an o-nitroxylidine and then nitrating this to give the 2,6-dinitro compound.

The nitrations can be carried out using conventional equipment take place, the new compounds with conventional nitrating agents, such as concentrated nitric acid, implemented.

In the case of the single-stage dinitration of the non-nitrated N-alkyl-3,4-xylidine or the mononitration of the N-alkylo-nitro-3,4-xylidine, the nitration is preferably carried out in concentrated nitric acid and optionally in the form of a solution in a solvent such as dichloroethane. The reaction is preferably accomplished nitric acid at a low temperature, which usually extend between about -10 ⁰ C and +10 ⁰ C using a large excess. It is advantageous to use a molar ratio of acid to xylidine of about 15: 1 in this reaction.

If it is desired to prepare the N- (alkyl) -mononitro-3,4-xylidine, the corresponding N- (alkyl) -3,4-xylidine is treated with a stoichiometric amount or a slight excess of nitric acid, preferably in the presence of concentrated sulfuric acid works. This reaction is advantageously carried out in the presence of a solvent such as dichloroethane, and at a temperature between about 5 ⁰ C

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and 35 ⁰ C carried out. The reaction gives a mixture of the desired N- (alkyl) -2-nitro-3,4-xylidine and N- (alkyl) -6-nitro-3,4-xylidine. The mixture can be separated into the individual components by column chromatography over silica gel using hexane as the eluent. This separation is not necessary if these compounds are used as intermediates for the preparation of the 2,6-dinitroxylidines, in which the isomer mixtures can be used in combination.

The N-alkyl-3,4-xylidines can be obtained by reacting 4-nitrooxylene or 3,4-xylidine (Formula VI) with a suitable ketone in a hydrogen atmosphere and in the presence of one conventional hydrogenation catalyst, such as palladium, produce. This reaction can be represented by the following scheme:

.CVD ". (VII)

in which X is an amino or nitro group, as a ketone Methyl ethyl ketone, methyl propyl ketone or ethyl propyl ketone is used and the group R ^ the above with respect to the general Formula IV has given meanings.

An alternative way to prepare the N- (alkyl) -3,4-xylidines of the general formula VII includes the reaction of 3,4-xylidine of the general formula VI, in which X is an amino group, with one of the above-mentioned ketones in the presence of an alkali metal cyanoborohydride, like NaBH ^ CN. It is also preferred to use a molecular sieve to remove the water formed during the reaction intercept. This reaction can be spread over a relatively wide range

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Be carried out temperature range extending from about 10 ⁰ C to 70 ⁰ C and is preferably carried out in the presence of a solvent, such as a Niedrigalkylalkohols having 1 to 4 carbon atoms.

According to a further process for the preparation of the compounds of the general formula VII, 3,4-xylidine is treated with a of the above-mentioned ketones in the presence of a molecular sieve and a solvent such as dry benzene. This reaction leads to the corresponding N- (alkylidene) -3,4-xylidine, the with an alkali metal borohydride or hydrogen and a hydrogenation catalyst to give the corresponding N- (alkyl) -3,4-xylidine can be reduced.

Because the N-alkyl group of some xylidines is asymmetric Contains carbon atom, the compounds can exist in the form of the optical isomers. In this case, include those mentioned N-alkylxylidines also include the individual optical isomers as well as their mixtures.

Since the separation into the optical isomers is costly and time consuming, it is generally preferred to use the racemic Mixtures instead of the separate optical. To use isomers. If this split is desired, the N-alkyl compounds with an optically active carboxylic acid such as L-tartaric acid be implemented, after which the diastereoisomers are separated in the usual way by fractional crystallization.

The compounds according to the invention and their preparation and Uses are further illustrated by the following Examples 39 to 63. All parts and percentages specified therein are based on weight unless otherwise specified.

Manufacture of N-alkylated anilines

The invention also extends to a new reductive

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Alkylation reaction optionally used to produce certain N-alkylated anilines described in the above Way to be described.

There are already processes for direct reductive alkylation of aromatic amines or via oxidized precursors using ketones, hydrogen gas, a noble metal catalyst and an acidic promoter; so is z. B. the reductive alkylation of aniline and Nitrobenzene in the presence of platinum and a monocarboxylic acid or a halogen acid is known. The reductive alkylation aromatic amines and nitro compounds in the presence of hydrogen, acetone, methanol, platinum and phosphoric acid also known.

In general, prior art methods employing weak acids such as acetic acid or strong acids such as Using hydrochloric acid has certain disadvantages. These disadvantages include low yields, long reaction times, low conversions and undesirable by-products arise due to competing side reactions, such as the reduction of the aromatic ring and / or the reduction of the ketone to the carbinol.

Accordingly, one or more of the above-mentioned disadvantages in manufacturing certain ones is an essential objective Overcome N-alkylated aromatic amines.

The N-alkylated ones formed by the process according to the invention aromatic amines correspond to the following general formula XX

(XX)!

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in the

R _{1 is} a cycloalkyl group with 3 to 6 carbon atoms or a secondary alkyl group with 3 to 8 carbon atoms, which is optionally simply substituted by a halogen atom or an alkoxy group with 1 to 4 carbon atoms,

Rj represents a hydrogen atom, a halogen atom, an alkoxy group having 1 to 4 carbon atoms, an alkyl group having 1 to 4 carbon atoms or a monosubstituted alkyl group having 1 to 4 carbon atoms substituted by a halogen atom or an alkoxy group having 1 to 4 carbon atoms contains, and

R _{3 represents} a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a trifluoromethyl group, a methylsulfonyl group or a halogen atom.

Examples of halogen substituents are fluorine, chlorine, bromine and iodine atoms. Representative representatives for alkyl substituents with 1 to 4 carbon atoms are methyl, ethyl, N-propyl, Isopropyl, N-butyl, tert-butyl, sec-butyl groups and The like. The cycloalkyl groups include cyclopropyl, cyclobutyl, cyclohexyl groups, etc.

Examples of secondary alkyl substituents having 3 to 8 carbon atoms are 2-propyl-, 2-butyl-3-pentyl-, 3-methyl-2-butyl-, 2-heptyl, 2-octyl groups and the like.

Examples of monosubstituted alkyl substituents, including of the secondary monosubstituted alkyl substituents are 3-chloro-2-propyl, 4-methoxy-2-butyl, 3-bromo-2-butyl, 2-chloropropyl, 2-ethoxybutyl groups and the like.

Preferred representatives of the compounds of the general formula XX which are prepared by the process according to the invention can include, for example: N-2-butyl-3,4-dimethyl-

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aniline, NS-Pentyl-S ^ -dimethylaniline, N-2-propyl-3,4-dimethylaniline, N-2-butyl-3-methyl ~ 4-t-butylaniline _/ N-3-pentyl- -3-methyl- 4-chloroaniline, N-3-pentyl-3-methyl-4-trifluoromethylaniline, N-2-hexyl-3,4-rdimethylaniline, N-3-pentyl-3-methoxymethyl-4-methylaniline, NS-pentyl-S- methoxymethyl ^ -trifluoromethylaniline, N ^ -butyl ^ -bromo-S-methylaniline, N-2-pentyl-4-bromo-3-methylaniline, N ^ -hexyl ^ -chloro-S-methylaniline, N-2-pentyl-3 -athoxy-4-methylaniline and N-2-butyl-3- (2-chloroethyl) -4-butylaniline.

The N-alkylated aromatic amines are obtained by reacting of the corresponding aromatic amine with the appropriate ketone, a noble metal catalyst and an acid with a pKa value from 0.3 to 2.0, preferably 0.5 to 1.0. The pKa value is defined as the negative decadic logarithm of the first ionization constant of the acid in water.

The aromatic used in the process according to the invention Amines correspond to the following general formula XXI

HH ₂

(XXI)

in which R ₂ and R _{3 have} the meanings given with regard to the general formula | t.

Examples of amines include: 3,4-xylidine, 3,4-diethylaniline, 3,4-di-: n-butylaniline, 3-methyl-4- * thylaniline, 3-methyl-4-trifluoromethylaniline, .S-methyl-i-chloroaniline, 3-Xthyl-4-bromaniliii, S-chloromethyl-4-methylaniline, 3-methoxymethyl-4-methylaniline and the like

409883/1418

The amines can be reacted directly with the ketone, or their oxidized precursors can be used, indirectly to form the N-alkylated aromatic amine. examples for oxidized precursors for the aromatic amines of the general Formula XXI are the corresponding nitro, nitroso, hydrazo, azo, azoxy, hydroxylamine compounds and diazonium salts or ship see bases.

Acids that can be used are, for example, 2-naphthalenesulfonic acid, p-toluenesulfonic acid, ethylbenzenesulfonic acid, trichloroacetic acid and the like. The ketone used is a compound which corresponds to the desired N-alkyl group. If a 2-propyl substituent is desired as the group R _{1, dimethyl ketone is used.}

More precisely, the ketones used according to the invention can through the following general formulas XXIII and XXV are circumscribed.

For the N-alkylated aromatic amines of the general formula XXII

HR ₁

(XXII)

in which R ₁ denotes a secondary alkyl group with 3 to 7 carbon atoms and the groups R ₂ and R _{3 have} the meanings given above with regard to the general formula XX, a ketone of the following general terms is used

Formula XXIII

R ₄ -CR ₅ (XXIII)

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in which R ₄ and R ₅ denote low molecular weight alkyl groups having 1 to 5 carbon atoms, with the proviso that the total number of carbon atoms in the group R ₄ and the group R ₅ does not exceed the number 6, whereby a number of 3 _{for the group R 1} up to 7 carbon atoms is ensured.

If desired, an N-alkylated aromatic amine is the general formula

(XXIV)

produce, in which R- is a secondary monosubstituted alkyl group having 3 or 4 carbon atoms, in which a halogen atom or an alkoxy group having 1 to 4 carbon atoms is contained as a substituent, and R ₂ and R _{3 are} the same as above with regard to the general Formula XX have the meanings given, a ketone of the general formula is used

0
R ₆ -CR ₇ (XXV)

one in which R _g and R _{7 are} low molecular weight alkyl groups with 1 or 2 carbon atoms, with the proviso that the total _{carbon content of the groups Rg plus R 7} does not exceed 3 carbon atoms and the group R _g or R ₇ simply with a halogen atom or an alkoxy group is substituted by 1 to 4 carbon atoms.

Examples of ketones that can be used in the process of the invention include, for example, acetone, 2-butanone, 2-pentanone, 3-pentanone, 2-hexanone, 3-hexanone, 2-heptanone, 3-haptanone, 4-heptanone, T-chloro-3-pentanone, 1-methoxy-3-pentanone, Ethoxy-2-propanone, methyl isobutyl ketone and the like.

409883 / UI 6

The noble metal catalysts used are those commonly used in hydrogenation reactions; H. Representative of Group VIII of the Periodic Table of the Platinum and Palladium Families. They are preferably in finely divided form absorbed or carried on a suitable substrate. Platinum and palladium are the preferred catalysts Carbon supported platinum is most preferred due to the fact that it is readily available commercially and the conversion of the ketone into the corresponding carbinol is avoided through its use occurs when using palladium. This achieves yields of 95% or more.

A typical method for carrying out the reductive alkylation of the invention is as follows. A pressure reactor is charged with the aromatic amine or an oxidized precursor thereof, the appropriate ketone, the acid promoter and the noble metal catalyst. The reactor is then deoxygenated by evacuation followed by purging with purified nitrogen. The reactor is then pressurized with hydrogen gas to a pressure of 0.70 to 5.62 kg / cm ² (10-80 pounds per square inch) (although higher pressures, limited by the equipment used, can be used if desired), after which the reaction mixture is heated to carry out the reaction. In general, temperatures in the range from 40 ^° C. to 150 ^° C. are suitable, temperatures from 60 ^° C. to 125 ^° C. being particularly preferred. In order to ensure a complete reaction, reaction times of 10 minutes to several hours are generally sufficient, during which time the pressure in the reactor is either maintained with the aid of hydrogen gas or is allowed to decrease, if desired. The reaction mixture is then allowed to cool, the reactor is vented, opened and the contents removed. The desired product is then

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worked up in the usual way.

Satisfactory results can be obtained when the amount of acid used in the "promoter system" is so small Value such as 0.1 mole per 100 moles of the amine or its oxidized Precursor amounts. The upper limit for the amount of acid is only limited by practical considerations. The most preferred Amount for the acid used ranges from 1 to 3 moles of acid per 100 moles of amine or its oxidized precursor.

The noble metal catalyst is preferably used in an amount used, which is no less than about 0.3 g of precious metal (preferably platinum) per mole of the amine to be alkylated or Amine precursor. When the catalyst absorbs onto a substrate the amounts of material should be adjusted so that at least an amount of about 0.3 g of the metal per mole of the amine or its precursor is present, disregarded the nature of the substrate on which the material is adsorbed.

The amount of metal typically used in commercially available Catalysts present ranges from 1 to 50!, Based on the weight of the carrier material. A preferred commercial one Catalyst contains 5% platinum on carbon and will in an amount of about 5% based on that either present in the reaction mixture or formed from the oxidized precursor Amiri, used.

The catalyst used in the process of the invention can be recycled in the usual way, with however, it is preferred to use the spent catalyst with a sufficient moderate fresh catalyst to reinforce thereby maintaining its activity. The amount of added fresh catalyst is usually lower than 10% of the catalyst originally used and extends preferably from 2 to 5% of this amount.

409 8 8 37U 16

ORIGINAL INSPECTED

The catalyst can be pre-reduced or the noble metal oxide can be used use and reduce it to the metal in the reaction mixture.

The ketone and the aromatic amine react more equimolar Base. When converting the amine to the corresponding N-alkylated Compound is consumed 1 mole of hydrogen. If an oxidized precursor is used instead of the amine, is additional hydrogen required for the reduction of the precursor. The preferred molar ratio of ketone to amine is about 1.1: 1 to about 1.5: 1.

The hydrogen is usually used in an amount which is significantly in excess of the amount required for the conversion. Preferably, it is used in an amount such that a pressure of about 0.70 kg / cm ^a (10 psi) is maintained, with pressures of about 2.91 to 5.62 kg / cm ^a (40-80 psi) particularly are preferred.

The N-alkylated aromatic formed by this process Amines are used as intermediates for the preparation of the corresponding 2,6-dinitroaniline herbicides and germ growth regulators suitable. .

In examples 9 * to * + 4> is the reductive alkylation with respect to the 4-nitro-o-xylene and 3,4-xylidine compounds described, it being understood, however, that any amines or their oxidized precursors can be used in place of these compounds. In either case, the parts are and percentages are by weight unless otherwise specified.

example 1 Nitration of N- (1-ethylpropyl) -3,4-dimethvlaniline

To a nitrating acid solution, which can be obtained by adding 145.2 g 70.5% by weight nitric acid (1.625 mol) and 116.6 g of 94.5% by weight sulfuric acid (1.125 mol) to 58.8 g of water,

409883 / U1S

-IL INSPECTED

are added in the course of 2 hours at 35 ^C C a solution of 101.0 g of 94.6 wt .-% sodium N- (1-ethylpropyl) -3,4-dimethylaniline (0.5 mol) in 143.5 ml Ethylene dichloride. The reaction is carried out for 1 hour at 35 ^° C. and the aqueous phase is then separated off. The organic phase is washed successively with 300 ml of a 5% sodium hydroxide solution and 300 ml of water. The organic solution is dried over anhydrous magnesium sulfate, filtered and ^{concentrated in vacuo at 70 °} C., giving 141.5 g of a crude product which contains 17 g (82.6% by weight) of N- (1-ethylpropyl-3 , 4-dimethyl-2,6-dinitroaniline and 14.2 g (10.0% by weight) of N-nitroso-N- (1-ethylpropyl) -3,4-dimethyl-2,6-dinitroaniline The overall yield of the desired 2,6-dinitroaniline is 72.6%.

Examples 2 to 10

These examples show the results obtained "obtained when (1-ethylpropyl) -3,4-dimethylaniline N- nitrided at 35 ⁰ C in reaction mixtures having the same molar ratios of nitric acid and sulfuric acid to the starting material but different water contents. In all cases the general reaction conditions are the same as those used in Example 1. In some cases the starting material is added without a solvent and the reaction mixtures are then extracted with toluene or xylene and worked up in the usual manner .

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Table I. H ₂ BO ₄ (M) Wt% H ₀ C Product stiiiiiei tee tzxxng Weight% % (a) yield _% co
I. AT THE) ⁾ % By weight, » B to N-nitroso _% total example 2.0 27.0 N-Nitroeo ^[a) 43.1 41.2 B ^ 81.5 No. Nitration of N- (1-ethylpropyl) -3,4-dimethylaniline (A) 2.0 31.1 48.6 61.0 29.5 40.3 77.5 Re * ction mix 2.0 35.6 31.9 81.0 12.2 48.0 90.7 2 mn 2.0 40.4 13.6 81.0 16.0 78.5 90.6 3 AT THE) 2.5 23.6 19.1 20.3 62.3 74.6 81.1 4th 3.0 2.5 31.7 74.8 81.4 13.6) 18.8 93.9 5 3.0 1.5 21.8 15.2 30.5 40.8 80.3 68.9 6th 3.0 1.5 30.0 48.9 56.0 27.5 28.1 78.8 1 3.0 1.5 34.8 33.1 81.0 12.4 51.3 88.9 8th 3.5 14.5 76.5 9 3.5 10
/ * \ KU.Ml 4 ~ m 2.5 2.5 2.5

(b) B-II- (1-Xtlylpropyl) -3,4-diiethyl-2,6-i ± Ltiitroeuilin

K) CD CO

Examples 11-13

Nitration of N- (1-ethylpropyl) -3,4-dimethylaniline

The following examples show that the nitration of N- (1-ethylpropyl) -3,4-dimethylaniline at 20-25 ° C in mixtures that contain 16.7 percent by weight, 21.7 percent by weight or 48.7 percent by weight of water contain, too low yields of both N- (1-Äthylpropy1) -3,4-dimethyl-2,6-dinitroaniline as well as N-nitroso-N- {1-ethylpropyl) -3,4-dimethyl-2,6-dinitroaniline to lead. This example shows the influence of the molar ratios and the water content on the yields and the product compositions.

The general procedure used is the same as that in. Example 1 described, where, in the following Table II indicated amounts are used and of 4.86 g of N- (1-ethylpropyl) -3,4-dimethylaniline in 15 ml of ethylene dichloride is assumed. In all cases, the addition time is 2 hours and the Treatment time ί hour. .

40 9883/1416

Table II Nitration of N- (1-ethylpropyl) -3,4-dimethylaniline (A) at 20 to 25 ° C

Example no.

Reaction mixture

HNO ₃ (M) H ₂ SO ₄ (M)% by weight

(M)

(M)

Product composition
Wt%

% By weight (a)

N-nitroso

(b)

yield

N-nitroso

(a)

% B

(b)

% Total

CO OO OD CO

11 12 13

1.5 2 _f 2 5.0

2.0 2.0 3.5

48.4 16.7 21.7

29.4 74.2

42.7 0

21, Ί 61.7

33.8 0

(a) N-nitroso-N- (1-ethylpropyl) -3,4-dimethyl-2,6-dinitroaniline

(b) B ■ N- (1-ethylpropyl) -3,4-dimethyl-2,6-dinitroaniline

Examples 14-15

Examples 14 and 15 given in Table III below illustrate the influence of the higher temperatures and water contents on the product composition and the total yield. The general conditions applied are the same like that of Example 1, the differences being indicated. The compositions are given in moles (M) and grams (g) .

A09883 / U1S

Table III

Nitration of N- (1-ethylpropyl) -3,4-diinethylaniline (A)

Reaction control yield

Example ENT, (M) H ₀ SO. (M) wt .-% EDC '''(M) Temperature% _rM ■ %

No ££ * N- ^{Nitroso lDJ} B

A (M) A (M) H ₂ OA (g)

14th 3, 25th 2, 25th 43, 3 O, 75 15th 3, 25th 2, 25th 49, 1 O, 75

N-nitroso ^IDJ B ^lc; total

60 23.5 64.5 88.0

70 23.5 73.5 87.0

(a) EDC = ethylene dichloride

(b) N-nitroso-N- (1-ethylpropyl) -3,4-dimethyl-2,6-dinitroaniline

(c) B = N- (I-ethylpropyl) -3,4-dimethyl-2,6-dinitroaniline

Example 16 Denitrosation of the crude nitration product of N- (1-Xthyl-

propyl) -3,4-dimethyl aniline

To a crude nitration solution containing 1550 g of 2,6-dinitro-N- (1-ethylpropyl) -3,4-dimethylaniline and 340 g of 2,6-dinitro-N-nitroso-N- (1-ethylpropyl) -3, Contains 4-dimethylaniline in 3700 ml of ethylene dichloride, 212 g of sulfamic acid and 2850 ml of 37.7% strength by weight hydrochloric acid are added. And keeping the mixture for 6 hours at 80 ⁰ C to reflux, then 2 1 to hater, and the aqueous phase is separated. The aqueous phase is extracted with 500 ml of ethylene dichloride, after which the organic phases are combined. The combined organic phases are washed with 3 1 of water, then separating the aqueous phase and Xthylendichlorid draws in vacuo at 68 ^e C to obtain 1915 g of a product is obtained, which in 1820 g of 2,6-dinitro-N- (1-ethylpropyl ) -3,4-dimethylaniline and less than 0.1% by weight of 2,6-dinitro-N-nitroso-N- (1-ethylpropyl) -3,4-dimethylaniline.

Examples 17-24

The examples for denitrosation of the crude nitration products obtained during the nitration of N- (1-xthylpropyl) · 3,4-dimethylaniline using the general guidelines given in Example 16 Conditions carried out. The molar ratios given in Table IV express the number of moles of reagent per Moles of N-nitroso by-product. In most cases the reactions are carried out in an autoclave.

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Table IV Denitrification of the raw nitration products from N-d-JfchylpropyD-S!

CO OO OO CO

P -

on

p No.

HCL (M)

H ₉ SOJB (Md

N-Hitroeo ^ΚΛΙ (M)

17th 17.2 18th 5.1 19th 5.1 20th 5.1 21 3.1 22nd 3.1 23 2.5 24 2.5

2.0 1.5 1.5 1.5 1.5 2.4 2.1 2.3

: - Tenp.
Cc) (e) (Hours.) yield
t tel W.) 80 (e) 5 · 90.0 10 ^ib) 100 (e) 2 97.0 60 ^ic) 80 (e) 6th 94.3 60 ^(b) 80 (e) 6th 97.0 60 ^(c) 80 (e) 6th 97.2 60 ^(b) 70 (β) 6th 95.5 50 ^ib) 80 1 96.4 50 ^(d) 80 6th 96.5 15th

(f)

(al N

(b) ethylene dichloride

(c) toluene

(d). n-propaneö.1

(e) Reaction carried out in an autoclave

(In all cases the percentage of N-nitroso-KMI-ethylpropyl is) - 3,4-dimethyl 2,6-dinitroaniline in the final product below 0.1% by weight.

Example 25 Nitration of H- (2-butyl) -3,4-dimethylaniline

To a nitrating acid solution, which is obtained by adding 134.1 g of 7Q, 5% strength by weight nitric acid (1.50 mol) and 101.1 g of 96% strength by weight sulfuric acid (1.00 mol) to form 87 , 2 g of water is added in the course of 2 hours at 50 to 55 ⁰ C a solution of 92.3 g of 95.9 wt .-% N- (2-butyl) .- 3,4-dimethylaniline in 66.5 ml of ethylene dichloride. The reaction is continued for a further hour at 55 ^° C., after which the aqueous phase is separated off.

The organic phase is washed successively with 500 ml of a 5% strength aqueous sodium hydroxide solution and 500 ml of water. The organic phase is then dried over anhydrous magnesium sulfate, filtered and concentrated at 70 ⁰ C in vacuum to yield 130.0 g of a crude product is obtained, which 10Oi, g (yield 75.5%) of 2,6-dinitro-N- (2-butyl-3,4-dimethylaniline and 22.0 g (yield 14.9 % l 2,6-dinitrone-nitroso-N- (2-butyli-3,4-dimethylaniline). The total yield based on the desired 2nd , 6 ~ dinitroaniline product is 90.4%.

Examples 26-28

The examples given in Table V below for explain the nitration of N- (2-butyl-3,4-dimethylaniline) the influence of the water content of the nitriding mixture on the product composition. It should be noted that the Use of a nitrating acid that has a higher water content and a lower nitric acid molar ratio, leads to a lower percentage of the by-product N-nitroso compound.

In all cases the general procedure des.Beispiels is applied by adding a solution of 4.53 g is at 35 ⁰ C N- (2-butyl-3,4-dimethylaniline as a starting material is added in the course of 2 hours in 15 ml Xthylendichlorid and the reaction continues ^{at 35 °} C. for a further hour.

A09883 / U16

Table V Nitration of N- (2-butyl) »3,4-dimethylaniline (C)

CD CD CO

Reaction mixture

Product composition

yield

example
ΧΓτ- ENT ₃ (M) H ₂ SO ₄ (M) H ₂ O Wt .-% ..
N-nitroso ^v ' % By weight ...
N-Dinitro ^K ' % ^(a) Dinitrö ^(t _% «R C (M) C (M) Wt% 70.8
19.8
10.5 21.4
70.6
76.3 N-nitroso 18.2
66.6
72.0 ^D 'total 26th
27
28 4.0
3.5
3.5 2.0
2.5
2.5 20.6
27.6
3D, 7 54.3
16.7
8.9 72.5
83.3
80.9

(a) N-nitroso-N- (2-butyl) -2,6-dinitro-3,4-dimethylaniline

(b) N- (2-butyl) -2,6-dinitro-3,4-dimethyl aniline

CD CD On 00

Examples 29-31

The examples given in Table VI below
illustrate the change in the overall yield and the product composition as a result of a change in the water content and the temperature of the reaction mixture during the nitration of N- (2-butyl) .- 3,4-dimethylaniline. These results indicate that for the nitration of N- (2-butyl) -3,4-dimethylaniline at the specified stoichiometric. Conditions a temperature of
about 50 ⁰ C and a water content of about 40 wt .-% are preferred.

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Table VI

Example no.

Reaction mixture

HNO ₃ (M) H ₂ SO ₄ (M) wt% EDC

C ^(a) (M)

/ M)

^H 2 °

(G)

Tatp. ( ⁰ C) yield

N-nitroso

(C)

(d)

%
total

CO GO OO CO

29 30th 31

3.25 3.25 3.25

2.25 2.25. 2.25

38.8 43.8 49.1

0.75 0.75 0.75

(a) C-N- (2- butyl) -3,4-dimethylaniline

(b) EDC «ethylene dichloride

(σ) N-Nitroso-N- (2-butyl) -2,6 -dinitro-3,4-dimethylaniline

(d) D »N- (2-butyl) -2,6-dinitro-3,4-dimethylaniline

15, 3 73 , 3 88 6th I. 18 1 68 , 9 87 0 ω
00 20, 7th 65 , 0 85 7th

CD CO Cn OO

Example 32 Denitrosation of the raw nitration product of N- (2- Butyl) -3,4-dimethylaniline

To a solution of 30 g of the crude nitration product containing 20.2 g of 2,6-dinitro-N- (2-butyl) -3,4-dimethyianiline and 6.84 g of 2,6-dinitro-N-nitroso-N- (2-butyl) -3,4-dimethylaniline in 15 ml of ethylene dichloride, 3.94 g of sulfamic acid and 9.84 g of 37.6% strength by weight hydrochloric acid are added. The mixture is stirred under pressure for 6 hours and heated to 80 ^° C., after this time 20 ml of water are added and the pH of the mixture is adjusted to a value of by carefully adding a 50% strength by weight aqueous sodium hydroxide solution 9 'to 11 a. The phases are allowed to separate and the aqueous layer is drawn off. The organic layer is washed with 20 ml of water, dried over anhydrous magnesium sulfate, filtered and concentrated in vacuo at 70 ^° C., giving 28.2 g of a product which contains 24.6 g (yield 93%) 2 , 6-dinitro-N- (2-butyl) -3,4-dimethylaniline and less than 0.1% by weight 2,6-dinitro-N- (2-butyl) -3> 4-dimethylaniline.

Example 33

A mixture of 1.83 g of water, 6.83 g of 96.9% strength by weight sulfuric acid (0.0675 Moll and 8.71 g of 70.5% strength by weight nitric acid (0.0975 mol) is prepared This solution is added in the course of 75 minutes at 35 ^° C. to 40 ^° C. to a solution of 5.93 g (0.03 mol) of N-2-butyl-3-chloro-4-methylaniline in 4 g of ethylene dichloride. The mixture is then heated to 40 to 45 ° C. for 2.25 hours and to 55 ° C. for a further 45 minutes. The mixture is then diluted with ethylene dichloride and treated with a dilute aqueous sodium hydroxide solution (to a pH of 10 to 11). washed, washed with fresh water, over magnesium

A09883 / U16

dried sulfate and filtered. When narrowing down you get 7/8 g of oil. This oil contains, like the thin-layer chromatographic Investigation shows a major ingredient and three minor ingredients.

The oil is' dissolved in 20 ml of ethylene dichloride, whereupon one 13 ml of concentrated hydrochloric acid and 1 g of sulfamic acid are added to the solution. The mixture is 7 hours heated to reflux, after which the thin-layer chromatographic analysis of an aliquot shows that one of the three minor components of the original oil has disappeared. The mixture is cooled, and the aqueous layer discarded. The organic layer will washed with water, dried over magnesium sulfate, filtered and concentrated to 5.7 g of an oil. The main ingredient this oil is isolated in the pure state by liquid chromatography and exists like that nuclear magnetic resonance spectrum shows from the desired N-ί2-butyl) -2, ö-dinitro ^ -chloro-p-toluidine.

Example 34

An acid solution is prepared by mixing 2.55 g of water, 6.91 g of 95.7% by weight sulfuric acid and 8.71 g of 70.5% by weight nitric acid. To this solution are added over a period of about 2 hours at 33 to 37 ⁰ C a solution of 6.3 g N-2-butyl-4-tert-butylaniline in 19 ml of ethylene dichloride. The reaction mixture is stirred ^{at 40 to 45 °} C. for 1.5 hours and then at 50 ^{° C. for one hour.} A further 1.93% strength by weight of 95.3% strength sulfuric acid is then added and the mixture is stirred at 50 ° C. for a further half hour. The investigations show that no unreacted N-

2-butyl-4-tert.-butylaniline or its mononitro derivative are included. The mixture is cooled, the organic Phase separated and washed with dilute aqueous sodium hydroxide solution and then with water. To the organic 13 ml of concentrated hydrochloric acid and 1.0 g of sulfamic acid are then added to the phase. This mixture is heated

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Reflux for 4 hours, then cool and discard the aqueous layer. The organic phase will washed with water and concentrated to 14.4 g of an oil. This oil is applied to a column filled with silica gel and eluted with toluene. The fastest The moving component is extracted from the silica using methylene chloride. The extract is concentrated, with 3.4 g (yield more than 38% of theory) of a yellow solid which is obtained as N-2-butyl-2, e-dinitro ^ -tert .. -butylaniline is identified.

Example 35 Preparation of N-sec-butyl-2-nitro-3,4-dimethylaniline and N-sec-butyl-6-nitro-3,4-dimethylaniline

Dissolve 5.3 g (0.03 mol) of N-sec-butyl * -3,4-rdimethylanilin in 10 ml of dichloroethane and the solution was carefully treated at 15 to 25 ⁰ G with nitrating acid (6 ml of concentrated sulfuric acid and 2, 7 g concentrated nitric acid). When the addition is complete, the mixture is poured into water. The organic layer is separated and purified by column chromatography on silica gel using hexane as the eluent. The compound eluted first is N-sec-butyl-2-nitro-3,4-dimethylaniline and is identified via the NMR and IR spectra. The second eluted compound is N-sec, -butyl-6-nitro-3,4-dimethylaniline, which is also characterized by the NMR spectrum. -

Example 36 Preparation of N- (1-ethylpropyl) -2,6-dinitro-3,4-dimethyl-

aniline

N- (1-Ethylpropyl) -2-nitro-3,4-dimethylaniline is prepared by following the procedure of Example 35 "by using N- (1 -Ethylpropyl) -3 _/ 4-dimethylaniline is used

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2,6-dinitro compound is obtained in good yield and with good purity by nitrating the 2-nitro compound using the procedure of Example 1.

Example 37

Similar to that described in Example 36, N- {1-ethylpropyl-6-nitro-3,4-dimethylaniline is prepared by the method of Example 35 by using the N-sec used there. -Butyl-3 _r 4 ~ dimethylaniline replaced by N- ί 1 -jithylpropyll 3,4-dimethylaniline. The 6-nitro compound is converted to the NnA "thylpropyl-2,6-dinitro-3,4-dimethylaniline according to the procedure of Example 1.

Example 38

A nitrating acid solution is prepared by adding 5.79 g {0.056 Moll 95.3% by weight sulfuric acid and 7 _f 27 g (0.083 Moll 70.5% by weight nitric acid to 1.27 g water) a solution of 6.15 g (0.025 Moll N, N-bis (2-chloroethyl-3,4-dimethylaniline in 15 ml of ethylene dichloride) is added with stirring. The addition takes place over 90 minutes at a temperature of 35 to 45 ° C, After completion of the addition, the mixture is stirred for further 2 hours at 30 to 40 ⁰ C, followed by discarding the lower layer abtrennt.und. the upper layer is washed with 10 ml portions of dilute sodium hydroxide solution and water in this order, The organic solution is dried over anhydrous magnesium sulfate and then chromatographed using a column filled with silica gel. Elution with benzene gives 3.73 g (44.5% 1 of a yellow solid which is N, N-bis- (2-chloroethyl-2,6-dinitro-3,4-dimethylaniline is, as shown in the NMR spectrum igt.

409883/1416

Example 39 Preparation of N- (1-ethylpropyl) -3,4-xylidine

10.0 grams are shaken in a Parr hydrogenator (0.066 mol) 4-nitro-o-xylene with 20 ml (0.019 mol) diethyl ketone, 0.5 g of 5% palladium-on-carbon as a catalyst and 0.5 g of benzoic acid at a hydrogen pressure of about 3 atmospheres. After the uptake of hydrogen has ended, the suspension is filtered and analyzed by gas-liquid chromatography, it is found that N- (1-ethylpropyl) -3,4-xylidine was formed in a yield of 83% has been.

Example 40 Preparation of N- (1-ethylpropyl) -3,4-xylidine

A solution of 3.2 g (0.01 mol) of 3,4-xylidine and 5 ml of diethyl ketone in 20 ml of methanol is stirred in the presence of 1.1 g of sodium cyanoborohydride and 3.0 g of a 3A molecular sieve at room temperature. The pH is measured every half hour and, if necessary, kept at a value of 6 by adding 5 drops of acetic acid each time. After seven hours, the molecular sieve is filtered off, the filtrate is diluted with 100 ml of water and acidified with hydrochloric acid. The solution is then made basic with solid potassium carbonate and extracted with ethyl ether. The ether solution is dried and then evaporated, the desired product being obtained with a yield of 97.5% and a purity of 93%, determined by gas-liquid chromatography. The compound has, at a pressure of 0.1 mm Hg a boiling point of 8O ⁰ C,

Analysis: ^ Ϊ3 ^Η 21 ^Ν

calc .: C 81.6 H 11.1 N 7.3% found: C 81.4 H 11.2 N 7.5%

409883 / U16

Example 41 Preparation of N-sec-Butyl-3,4-xylidine

Uo

Following the procedure of Example I, using an equivalent amount of methyl ethyl ketone instead of the diethyl ketone used there, N-sec-butyl-3,4-xylidine is prepared. The desired product is obtained in quantitative yield with a purity of 96%. At a pressure of 0.4 mm Hg, it has a boiling point of 75 to 77 ^° C. and the following analysis values:

Analysis: ^c i2 ^H 3 9 ^N

calc .: C 81.3 H 10.8 N 7.9% found: C 81.4 H 10.8 N 7.9%

Example 42 Preparation of N-sec-Butyl-3,4-xylidine

To 79.2 g '(1.0 mol) of methyl ethyl ketone and 121.0 g' (3.0 mol) 3,4-dimethylaniline in 1 liter of dry benzene as a solvent 300 g of molecular sieve (type 5A) are added. The reaction mixture is stirred for 16 hours at room temperature. The mixture is then used to separate the molecular sieve filtered, which is washed with dry benzene. The benzene solutions are combined and evaporated in vacuo, whereby 198 g (100% i of the desired product are obtained. The product is sensitive to hydrolysis and is therefore immediately reduced in a hydrogenation device using 5% palladium on carbon as a catalyst to form N-sec-butyl 3,4-xylidin'reduced.

409883/1416

Examples 43-44

Preparation of N-sec.-Butyl ^ -nitro-S, 4-xylidine and N-sec-butyl-6-nitro-3,4-xylidine

Dissolve 5.3 g (0.03 mol) of N-sec-butyl-3,4-xylidine in 5 0 ml of dichloroethane and the solution was carefully treated with 15 - 25 ^e C and nitrating acid (6 ml of concentrated sulfuric acid and 2, 7 g concentrated nitric acid). When the addition is complete, the mixture is poured into water. The organic layer is separated and purified by column chromatography over silica gel and using hexane as the eluent. The first compound eluted is N-sec, -butyl-2-nitro-3,4-xylidine. It is characterized by the NMR spectrum and the IR spectrum. The second eluted compound is N-sec-butyl-6-nitro-3,4-xylidine. It is characterized by the NMR and ΙΕ spectra. The analysis sample of the 6-nitro compound has a melting point of 73 to 75 ° C and the following analysis values:

Analysis t j «J ΰ M ₂ O ₂ N 12 ^ 6% . ber.s C 64, N 12, 6% gef '. s C 64, Examples 45 - 46 N -C 3 -sthylpropyl) -2-nitro-3 , 4-xylidine and Production of N- (1-Sthylpropyl) -6-nitrö-3, rß K βρ. r 4-xylidine , 6 H 8.2

The above compounds are prepared and isolated after Procedure of Examples 43 and 44 by replacing there used an equivalent amount of N-sec-butyl-3,4-xylidins N- (1-ethylpropyl) -3,4-xylidine was used.

After recrystallization from methanol, the 6-nitro compound has a melting point of 58 to 60 ^° C. and the following analytical values:

«09883 / Ί41Β

Analysis: ^c -j3 ^H 20 ^N 2 ° 2

calc .: C 66.1 H 8.5 N 11.9% found: C 66.1 H 8.6 N 11.7%

After chromatographic purification, the 2-nitro compound is in the form of an oil that has the following analytical values owns

Analy s e

^C 13 ^H 2 ( C. 2 ° 2 1 H 8th , 5 N 1 1, 9 % ber .: C. 66 7th H 8th / 9 N 1 2, O % found: 67,

The 6-nitro compound can alternatively be prepared by adding 3.8 g (0.02 mol) of N-1- (ethylpropyl) -3,4-xylidine with 5.0 ml (0.08 mol) of 70% strength by weight concentrated nitric acid according to Example 50 below. The wished Product is usually isolated by silica gel chromatography.

Examples 47-49

The selective pre-emergence herbicidal activity of the compounds of the invention is illustrated by the following studies, in which seeds from various monocotyledonous and dicotyledonous plants are mixed separately with potting soil, after which a 1.27 cm (1/2 ") thick layer is about 3.8 cm (1 1/2 ") thick layer of potting soil is applied, which is present in separate plastic pots measuring 6.35 χ 6.35 cm (2 1/1 c 2 1/1 "). After planting, the pots are selected with the sprayed aqueous acetone solution containing compound to be examined in an amount such that an amount is present per pot of the test compound, the 0.0672 to 11.20 kg / ha (0.06 to 10 pounds per acre) is equivalent. The treated pots are then placed on greenhouse shelves, watered,

409883 / H16

and maintained using standard greenhouse practices. Three or four weeks after treatment, the examination is suspended and each pot is examined and evaluated according to the rating system given below. The results obtained are in the Table VII below.

Evaluation system of percentage growth difference compared to the 'control plants *

0 - no effect Γ- possible effect

2 - minor effect

3 - moderate effect

5 - significant damage

6 - herbicidal effect

7 - good herbicidal effect

8 - almost complete destruction

9 - complete kill

4 - abnormal growth, i.e. H. a clearly physiological one

Deformity, which, however, is present with an overall effect that receives a rating number lower than 5.

* - Based on a visual evaluation of the stand, the size, thriving, chlorosis, growth deformity and overall appearance of the plant.

Plant abbreviation

CR - Fingergrass (Digitaria sanguinalis) PI - Foxtailgrass (Amaranthus retroflexus) LA - White goosefoot (Chenopodium album)

COR - Maize (Zea mays) WO - Wild oat (Avenia fatua) MU - Mustard (Brassica kaber)

RAG - Ambrosia (Ambrosia artemisiifolia)

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0 10 1 - 25th 11 - 40 26 - 60 41 - 75 61 - 90 76 - 99 91 - 100

BA - Chicken millet (Echxnochloa crusgalli) GRF - Green foxtail grass (Setaria viridis) MG - annual bindweed (Itomoea purturea and

Itomoea hederacea)

COT - cotton (Gossypium hirsutum) SB - sugar beet (Beta bulugaris) SOY - soybean (Glyzine max)

409883 / U16

Table VIl

CO OO OO CO

Example no.

Active ingredient

47

48

49

Herbiside pre-emergence effect

plants

annual weeds

Useful plants

hnch;

.CH ₃

2.24

2.24 1.12

• 4.48 2.24 1.12 (1)

(D

5
3

ΒΆ CR GRF WD COR COT SOY SB 2 9 9 9 2 0 2 0 0 O 8th 9 9 O 0 0 0 0 O 7th 9 • 9 O 0 0 0 0

O O

9 9 9 2 0 ( ε * 9 9 5 0 0 ( VO 9 8th 3 "F. 3 2 3 0

0 3 9 7th 0 0 0 0 0 0 3 8th 5 0 0 0 0 0

on

Examples 50-63

The method of converting the compounds of the invention in 2, 6-dinitroaniline is illustrated by the examples 50 to 54. The usefulness of the products formed in this way is illustrated by Comparative Examples 55-63.

Example 50 Preparation of N-sec-butyl-2,6-dinitro-3,4-xylidine

One gives 1.2 g (6.7 10 ^-3 χ minor N-sec-butyl-3,4-xylidine at 15 ⁰ C to 13 ml of 70 wt .-% nitric acid. After 1 hour, pour the reaction mixture to Ice water and extracted with ethyl ether. The extract is dried over magnesium sulfate and evaporated in vacuo to give 1.55 g of the desired product in the form of a solid residue. The product is purified by chromatography over silica gel using hexane as the eluent total weight of the obtained purified, a melting point from 41 to 45 ⁰ C-containing product is 1.1 g (60%). recrystallization from hexane gives an analytical sample with a melting point of 43-44 ° C and the following analytical values%

Analysis: ^c i2 ^H 17 ^N 3 ° 4

calc .: C 59.3 H 6.4 N 15.7 % found : C 54.0 H 6.2 N 15.7 ^

Example 51 Preparation of N- (1-ethylpropyl) -2,6-dinitro-3,4-xvlidine

The title compound is obtained by following the procedure of Example 50 by replacing the N-sec.-Buty1-3,4-xylidine used there with an equivalent amount of N -. (1-A * thylpropyl) -3,4-xylidine. The desired product is obtained with a yield of 80%. The purification occurs by ümkristallisation from methanol to form a crystalline product having a melting point of 56-57 ⁰ C and the following analytical values:

A09883 / U16

Analysis: ^c i3 ^H ig ^N 3 ^ 4

calc .: C 55.5 H 6.8 N 14.9% found: C 55.4 H 6.8 N 15.0%

Example 52 Preparation of N- (1-ethylpropyl) -2,6-dinjtro-3,4-xylidine

1.0 g (4 × 1 θ " ³ mol) of N- (1-ethylpropyl) -2-nitro-3,4-xylidine are added to 10 ml of nitric acid (concentration 70% by weight). After 90 minutes the reaction mixture is worked up as described in Example 50, the desired crude dinitro product being obtained in a yield of 100%. Gas-liquid chromatography shows that this product has a purity of 97%.

Example 53 Preparation of N- (1-ethylpropyl) -2,6-dinitro-3,4-xylidine

The title compound is obtained in a 90% yield of the crude material following the procedure of Example 52, by replacing the 2-nitro compound used there with a equivalent amount of N- (I-ethylpropyli-6-nitro-3,4-xylidine is used. The product obtained has a purity of 90%.

Example 54

A flask is charged with 41.0 g (0.214 mol) of N-3-pentyl-3,4-dimethylaniline and 128 ml of 1,2-dichloroethane. Then the solution is stirred and cooled on Q to 5 ° C and are in the course .of 135 .min at 0 to 5 ⁰ C, 254 g (3.22 Moll 80 wt .-% nitric acid to. After the addition is maintained the reaction mixture for 240 minutes at 0 to 5 ⁰ C. After this time, pouring the cold reaction mixture to 254 g of ice and sets 128 ml of dichloroethane to. After removal of the aqueous phase, the product solution with a 5% aqueous bicarbonate solution and water The crude product is obtained through

A09883 / U16

Dry the organic layer over magnesium sulfate, filter and evaporating the solvent from the filtrate under reduced pressure. 52.3 g (yield 89.7%) of the crude are obtained Product. The real yield is 79.3%. The product crystallizes when stored under ambient conditions.

Examples 55-63

The selective pre-emergence herbicidal action of the invention Connections are illustrated by the following studies, in which the seeds of various monocot and Dicotyledonous plants are separately mixed with potting soil, followed by a 3.27 cm {3/2 ") layer of this seed-soil mixture is applied to a 3.8 cm (3 3/2 ") thick layer of potting soil, which is in separate plastic pots with The dimensions are 6.35 χ 6.35 cm (2 3/2 χ 2 3/2 "} After planting, the pots are filled with a solution of the selected compound to be investigated in a water-acetone mixture sprayed in such an amount that an application rate of the compound to be investigated of 0.0672 to 31.20 kg / ha (0.06 - 30 pounds per acre) is equivalent. The treated pots are then placed on greenhouse shelves and placed in customary Watered and cared for wisely. Three to four weeks after the treatment, the examinations are ended and each pot examined and rated using the above rating system. The results of these studies are in the Table VIII below and show the herbicidal effectiveness of the formed by the process according to the invention Products and illustrate the extraordinary effect of N-sec-butyl-2,6-dinitro-3,4-xylidine, N- (3-ethylpropyl) -2,6-dinitro-3,4-xylidine and N- (3-methylbutyl) -2,6-dinitro-3,4-xylidine and the practical ineffectiveness of the closely related homologues of these compounds, which are applied in equivalent amounts and can be used in double the order quantity.

409883 / U16

Active ingredient structure

Table VIII

Herbicides pre-emergence effect Application amount

kg / ha (Ib / acre) ——

plants

annual weeds

Crops

I.
ί 57 OgH HH-C
0 H (CaHs) s
CH ₃ (0.5) 0.56
(0.25) 0.28
(0.13) 0.15
(0.06) 0.067 T.A MIi PI RAG 6th
4th
2
2 RA OR 9
9 WHERE COR ■ * COT SOi! SB CH ₃ XI 7th
6th
6th
"5 8th·
7th
3
3 9
9
7th
6th 9
9 7 -
3
3 mo ο ο oooo oooo Λ
3-
3
0
Ό (1) 1.12
(0.5) 0.56
(0.25) 0.28 ooo ■ 8th ^ ¹ CH ₃ 8th
I. moo 8th
8th vovovo 1.
O
O ooo ooo ooo *
0
C.
0. CH ₃ VT T ** '
<■ »ju JL ■ SS C. (1) 1.12
(0.5) 0.56
(0.25) 0.28 *
• 0
0
0 9
I. - ^ OH ₃
^Ε * XIII 7th
7th
■ 5 7th
5
O 9
8th
7th 9
9
7th HOO O
O ooo HOO 5
0
0 SS

(Jl Ui.

At- O ₂ Kw Active ingredient I. ¹ • η XIV XVI Herbicides Table VIII 2nd right ) Q annual • 0 Weeds ÜA i 0 Uk RElances WHERE · Crops COT isoY SB • to game
Kh " structure iso Pre-act 0 MU Pl RAG 0 MG 0 COR ro Order quantity • 0 0 7th GRF 0 I. 0 0 0 CD
CD 58 NH-C4H9- ^ »Y ^ CH ₃ kcr / ha Hb / a < 1, 12th 0 0 0 7th 0 0 0 0 0 cn CH ₃ O, 56 0 0 0 0 2 0 0 0 0 0 CX) HN-C ₄ H ₉ - XV 0, 28 0 0 1 0 CH (CH ₃ 0 O ₂ N, 0 • 0 C- O CH _{3 3} ρ 7th 0. .0 0 0 CD HNCH ₂ CH ₂ 1, 12th 0 0 1 0 0 0 0 0 I.
Ui OO
CO 59 O ₂ N s> ^ vs ^ NO O, 56 0 0 0 0 5 0 0 0 0 0 I. N. τ χ O, 28 0 0 0 2 0 * "» 0 0 _ » CH ₅ 7th 0 0 0 0 CT) 1, 12th 0 2 Ό ■ 0 0 0 0 60 O, 56 0 0 0 0 (D (0.5) . (0.25) ß! » (0.25) (1) (0.5)

Table VIII

Example no.

Active ingredient

Herbicidal pre-emergence effect

Structure plants

kg / ha (lb / acre) - -r ~ weeds

LA IiU PI RAG MG BA CR GRP WO

Useful plants

COR COT SOY SB

O CO OO OO CO

61

(1) 1.12

O O

0 0
OO O

O O O 0 "

O O

H ₃

CH ₃

XVII O O

O O

62

HN-CH ₂ C (CHa) ₃ .NO ₂

(2) 4.48 (1) 1/12 0005 OO 0000 OO

O O

CH ₃

XVIII O O

O O

63

CH ₃ HN-CC-CH ₂ CH ₃

I CH ₃ N0

(J) 1/12 (5) 5.60

O
O

O 7
O 2

O O O O

O O

O O

example

An autoclave is charged with 24.2 g (0.20 mol) of 3,4-xylidine, 38.4 g (0.44 mol) of diethyl ketone, 1.2 g of 5% palladium on carbon and 0.90 g (2 mol -%) 2-naphthalenesulfonic acid; the autoclave is then closed, evacuated, flushed with nitrogen and pressurized with hydrogen gas to 3.30 kg / cm ^a (47 psi). The temperature of the autoclave is increased to 6O ⁰ C, during about 45 minutes and held at 60 to 65 ⁰ C then lowered to about 25 ⁰ C. The autoclave is then vented, opened and the contents removed and filtered to separate off the catalyst. The lower layer of the filtrate is separated in a separatory funnel, whereupon the catalyst cake, the filter flask and the

Rinse the separating funnel with 10 ml of diethyl ketone and the rinsing liquid combined with the organic phase, which is then evaporated to a constant weight of 38.2 g. The received Product is 97.2% pure, which equates to: 97.2% conversion and 97.2% yield of N- (3-pentyl) -3,4-xylidine is equivalent to.

Comparative example fc 5 »- Ψ6

The following examples illustrate the influence of different promoter acids on the conversion of a passage and on the Yield of the N-alkylated product obtained. The applied general procedure is the same as that of Example ** JiM. where the amount of acid used in mol%, based on 100 moles of 3,4-xylidine, and the relative amounts of ketone and catalyst in Table IX below along with the reaction conditions, the percentages of unreacted 3,4-xylidine, the percentage of 3,4-xylidine converted into the desired product, the percentage The amount of product formed and the percentage of the yield based on the theoretical yield are given. In all Cases are diethyl ketone and 3,4-xylidine as starting materials used. In general, a fresh, 5% platinum-based

409883/1416

Comprehensive carbon catalyst is used, being in some Cases the catalyst is reused and in other cases 10% platinum-on-carbon can be used as a catalyst. These results show that acids? the essentially pKa values of 0 and acids with pKa values above 2.0 ^ such as phosphoric acid , Acetic acid and benzoic acids, lower yields and conversions give as acids with a pKa value of corresponds roughly to that of the arylsulfonic acids.

■ 409883/1418

Wk

Table IX Reductive alkylation of 3,4-xylidine

Bei- ketone (M)

game Xyüdin ((M)
No.

acid

pKa mol% catalyst (g) temp. pressure hours to

Acid xylidine (M) ⁰ C 'kg / cn ?. to terminate

2.2
2.2
2.2
2.2

2.2
2.2
2.2

H ₂ SO ₄

HCl

CH ₃ - ^ - SO ₃ H

CH ₃ - ^ - SO ₃ H

(d

0.0 0.0 0.70 0.70

0.90 2.0

0.90 2.0

o.9O 2.0 6.0 6.0 6.0 6.0

6 _r 0 6.0 6.0

59-69 3.52-2.25 1.0 (50-32) 60-69 3.52-2.25 0.3 (50-32) 66-70 3.52-2.39 0.3 (50-34) 58-65 3.23-1.97 0.5 (46-28) 59-70 3.52-2.25 0.3 (50-32)

61-70 0.3

60-67 3.52-2.25 0.4 (50-32)

2.2 H ₃ PO ₄ 2.12

2.2 ClCH ₂ CO ₂ H 2.85 * a) The catalyst was recycled once b) The catalyst was recycled twice

55-63 3.52-2.25 1.25

(50-32) 66-76 3.52-2.39 0.2

(50-34) c) As a catalyst was

% Platinum-on-carbon used.

6.0 6.0

d) Water was added to the reaction mixture.

70.1 13.6 77.4 13.6 90.1 0.2 95.9 - 0.7

(Continuation of Table IX)

Wt% wt%%%

Product unreacted material Aging Yield

70.5 88.0

89.0 89.3

94.7 95.8

S3- 88.8 4.1 85.7 91.3

CD CO OO ■

»! Θ 64- 75.7 10.7 73.3 87.5

• «5- 88.8 0.0 96.8 96.8

85.5 5.2 81.5 88.4

83.2 3.5 80.9 85.5

Bei- ketone (M)
game xylidine (M)
No.

(Adjustment to Table IX) Reductive alkylation of 3,4-xylidine

acid

pKa

Mbl-% catalyst (g) acid xylidine (M)

Tenp.
⁰ C

Pressure kg / cm ^a hours to (psi) termination

2.2

4.19 1.0

6.0

58-60

3.52-2.39 (50-34)

1.33

2.2

"^ -CO ₂ H ^(a 4.19 1.0

6.0

60-65 3.52-2.39 0.97

(50-34)

.το
<o

CO OO CO

2.2

2.2

2.2

(b

4.19 1.0

CO ₂ H 4.19 1.0

4.19 1.0

6.0

6.0

6.0

60-83 3.52-2.67 (50-38)

55-56

55-59

3.52-2.39 (50-34)

3.52-2.39 (50-34)

2.0

2.0

2.0

2.2

2.2
2.2

CH ₃ CO ₂ H

CH ₃ CO ₃ H

4.19 1.0

4.75 1.7

4.75 1.7

4.75 2.0

3.0 3.0 3.0 6.0

(c (c

(c

56-61
58-62
61-64
60-68

3,52-J, 97

(50-28)

3.52-2.25

(50-32)

3.52-2.25

(50-32)

3.52-2.39

(50-34)

18.8 1.8

2.3

0.9

NJ CO CD Ol OO

(Continuation of Table IX)

= »% GeWe ~% not-%%

No product set material conversion yield

85.5 β, 2,81.3 89.7

30 ^ 3 4.9 83.1 90.2

° & $ S0 _ff 8 4.9 '83.1 90.0

90.6 0 89.5 89.5

89.3 3.6

71.7 16.9

• 78.8 11.5

85.3 90.3 61.5 82.9 72.3 86.5

CD cn 00

Examples

The following examples illustrate the fact that 10% platinum-on-carbon is used as a catalyst in the presence of p-Toluenesulfonic acid repeatedly recycled as promoter acid and can be reused with excellent conversions and product yields. The applied general procedural measures are those used in example 5 €, where diethyl ketone and 3,4-xylidine are used as the starting point and the reaction conditions given in Table X below is being worked on.

409883 / U1S

Table X Reductive alkylation of 3,4-xylidine using recycled catalyst

⁵ ^ " ketone (M) mol-% cataly- number of tenp. Pressure hours to wt-% wt-%%%

game Xylidine (M) Acid sator (g) Recyclisie- o _c kg / cm ² for loading Pro- not- üfnwand- Ausbeu-

No. Xylidine stanchions (psi) end product conversion te

(M) tes mate

ral

ΎΓ 2.2 2.0 3.0 (a) O 63-71 3.52-2.25 0.3 87.6 3.6

(50-32)

7β "2.2 2.0 3.0 (a) 1

2 «5 79-2.2 2.0 3.0 (a) 2

oo _Λ

⁰⁰ <&> βϋ 2.2 2.0 3.0 (a) 3

61-69 3.52-2.25
(50-32) 0.3 92.6 1.3 60-68 3.52-2.25
(50-32) 0.4 93.4 0.3 61-66 3.52-2.25
(50-32) 0.5 94.4 0.0 59-62 (3.52-2.39
(50-34) 2.5 98.0 0.1 59-62 3.52-2.32 0.9 96.0 0.0

2.2 2.0 3.0 (a) 4

cn 2 ^ 83-2.2 2.0 3.0 (b) 5

(50-33). (a) The catalyst used is 10% platinum-on-carbon.

(b) The catalyst is replenished with 0.12 g of fresh 10% platinum on carbon.

88.8 94.3 I. 91.8 94.0 en
ω 93.4 93.9 94.3 94.3 99.9 100 98.7 98.7

■ P »K) CD

Example ■■

The following examples illustrate the reductive alkylation of 4-nitro-o-xylene with diethyl ketone, initially 1.2 g fresh catalyst (5% platinum-on-carbon) and ß-naphthalenesulfonic acid and the used catalyst is then returned with a small amount of fresh catalyst and reused. In this way, after repeated recycling of the catalyst achieved excellent conversions and yields. The results obtained are as follows Table XI summarized.

409883 / H16

Table XI

Reductive alkylation of 4-nitro-o-xylene using recycled catalyst (platinum-on-carbon) , ■ "

At- remarks
game

Additional Ternp. StrL up to wt .-% catalyst ⁰ C termination of alcohol (g) in the DEK

Distillate analysis

Product xylidine

Convert—
lung

yield

¥ fresh kata none 29-70 1,2.3 lyser • OiA CLJP .1. Recycling none 28-67 0.90 *> ·
O ⁰ Il <8 * 2. recycling none 26-70 0.97 CO
OO 3. Recycling 0.24 g 28r-69 0.82 OO % st tion CO 4. Recycling 0.12 g 27-68 0.86 * "■ ·» tion __ » 5. Recycling 0.12 g 29-67 0.98 C ^ * 9- tion 6. Recycling 0.12 g 28-60 0.85 tion
7. Recycling 0.12 g 30-69 0.97 tion 8. Recycling 0.12 g 29-63 - tion 9. Recycling 0.12 g 30-57 - tion

87.5

2.0

t, Ö

94.0

<2 85.5 '. 7 _r 4:. · ■ .. '84.3 98.2 ι 5 96.9 - 0.14. 98.8 98.9 I.
U)
r 5 86.7: 0.0 96.9 96-, 9 5
<2 88.5
86.5 0.0
0.39 97.0
98.1 97.0
99.0 £ 2 85.8 0.38 96.8 97.3 7th 95.2 0.0 96.4 96.4 O 95.1 0, 0 96.4 96.4 3 95.5 0.0 97.7 97.7

ro

NJ CD CO Cn OO

Examples »-

The following examples, relating to the reductive alkylation of 4-nitro-o-xylene with diethyl ketone in the presence of 2-naphthalenesulfuric acid and 5% platinum-on-carbon, are carried out at 70 - 80 ^a C and a pressure of 2.8-1 - 3.52 kg / cm ² (40-50 psi) using the general procedure of Example 5 * - The results obtained are shown in Table XII below.

409883/1416

Table XII Reductive alkylation of 4-nitro-o-xylene

^ ___ reaction conditions product composition

At- ketone (M) Kbl-% fresh ca- consumption- time wt. ~% Wt.%%%

play 4-nitro-o-xylene acid catalyst (g) ter Kata- (hrs.) product 3,4-xyli- unwall-

lyser din lung loot

AoO ^ 1.2 2.0 1.2 0.0 1.50 88.2 4.2

1 , 6 2.0 1.2 0.0 - 88.8 1 , 2 2.0 ¹ ' ² , 0.0 1.50 88.2 1 , 2 3.0 1.2 0.0 3.00 90.0 3 , 0 2.0 0.1 2.5 0.63 96.5 1 , 2 3.0 0.0 2.8 3.00 69.7

O CO

oo Atfi ⁹ ^ ¹ '2 3.0 0.0 2.8 3.00 69.7 19.5

co cn

90.0 92.7 I. 89.0 95.9 98.1 99.8 96.3 96.3 65.5 94.5

ro

ro

CD CD

cn

OP

Examples 8 - -1

The following examples given in Table XIII for the reductive alkylation of 4-nitro-o-xylene with Diethyl ketone in the presence of 0.78 g of spent catalyst (5% platinum-on-carbon) and 2-naphthalenesulfonic acid illustrate the effect of the temperature, the pressure and the concentration of the promoter acid the percentage conversion.

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at Reductive Ketone (M) Md1-% Tabel XIII . pressure Time Wt% Wt% % % 1 game Nitro-o-xylene acid kg / an? (psi) (Hours.) product 3,4-xyli-
din umwand
lung " • The end
prey Ch 1.60 1 Alkylation of 4-nitro-o-xylene 1.41 (20) 24 2.7 24.1 2.3 36.6 ¹ 1.60 1 Tanp. 1.41 (20) 24 1.6 23.9 15.8 53.0 / fcip> θβ ~ 1.60 1 ⁰ C 4.22 (60) 12.5 93.1 0 94.6 94.6 AÖY ¹ ^ ⁺ * 1.60 3 40 1.41 (20) 4.4 5.3 36.7 4.2 50.0 1.60 3 80 1.41 (20) 9.5 85.5 0 94.0 94.0 1.60 3 80 4.22 (60) .3.3 95.1 0 92.0 92.0 AAo MA 2.20 2 40 2.81 (40) 5.5 67.1 0 97.0 97.0 2.80 •1 80 4.22 (60) 12.5 8.7 37.8 " 7.0 66.6 AA'h Mfi 2.80 1 80 4.22 (60) 4.0 88.0 8.8 83.5. 95.5 ♦ ^
O ΑΜΪ> ^ * 2.80 3 60 4.22 (60) 7.0 92.2 0 98.5 98.5 OCJ Λ / lVL ΓνΓβ 2.80 3 40 4.22 (60) 3.0 92.3 0.1 96.9 97.0 OO AAS> 0 * 2.80 3 80 1.41 (20) 8.5 83.5 0 97.0 97.0 2.80 3 40 4.22 (60) 3.0 92.3 0.1 96.9 97.0 λλχήμ 2.80 3 80 4.22 (60) 3.0 90.1 0 92.0 92.0 80 80 80

Example <344l Production of N-3-pentyl &, QC, OC-trifluoro-p-toluidine

A pressure vessel is charged with 8.05 g (0.05 mol) of oC, oil, oC-trifluor-p-toluidine, 6.9 g (0.08 mol) of diethyl ketone, 0.3 g of 5% platinum-based Carbon and 0.23 g of 2-naphthalenesulfonic acid. Then, the vessel is sealed and heated on the Reaktxonsmischung 55 to 60 ⁰ C. Then, bringing the pressure of the vessel with hydrogen gas to 3.16 to 3.52 kg / cm ² (45 - 50 psi). The mixture is allowed to react until the hydrogen stops. Then the material is cooled to room temperature, the vessel is ventilated, the mixture is removed from the vessel, filtered and the lower water layer is separated from the filtrate. The filtrate is evaporated in vacuo, 11.2 g of the desired product being obtained in the form of an oil (yield 97% of theory). The identity of the product is confirmed by nuclear magnetic resonance spectroscopy and by elemental analysis, which gives a nitrogen content of 5.92%, which corresponds to the theoretical value of 6.06%.

Example 14-9-

Production of N- (2-butyl) -4-tert-butylaniline

A 500 ml pressure reaction vessel is charged with 18.0 g (0.1 mol) of p-tert-butyl-nitrobenzene, 13.6 g (0.22 mol) of methyl ethyl ketone, 0.6 g of platinum-on-carbon and 0, 46 g of 2-naphthalenesulfonic acid monohydrate and seal the reaction vessel. The reaction vessel is then pressurized with hydrogen gas, after which the material is ^{hydrogenated at 60 to 75 °} C. until about 6% more hydrogen than the theoretical amount has been consumed. The system is then cooled to room temperature, ventilated and the contents removed from the reaction vessel and filtered. The lower layer of the filtrate is discarded while the upper layer is evaporated in vacuo to give 20.7 g of the true crude product (which corresponds to a yield of about 100% of theory.

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speaks). The product is through the infrared absorption spectrum identified that is identical to an analytically pure Sample of N- (2-butyl) -4-tert-butylaniline.

AIo

Example 444 Preparation of N- (2-Butvl) ~ 3-chloro-p-toluidine

A 500 ml pressure reaction vessel is charged with 28.3 g (0.2 mol) of 3-chloro-p-toluidine, 23.0 g (0.32 mol) of methyl ethyl ketone, 1.2 g of 5% platinum-on-carbon and 0 , 9 g of 2-naphthalene sulfonic acid and seal the reaction vessel, which is then pressurized to about 3.59 kg / cm ² (51 psi) with hydrogen gas, after which the temperature is increased to 65 ° C. And this pressure is maintained, until a drop in pressure indicates that the theoretical amount of hydrogen has been used. The system is then cooled to room temperature, vented and the contents removed. The underwater layer is discarded and the upper layer is evaporated in vacuo to give the crude desired product with a yield of 100%. The comparison of the crude material via the infrared spectrum and the nuclear magnetic resonance spectrum with pure N- (2-butyl) -3-chloro-p-toluidine confirms its structure and shows. : that the product is contaminated with less than 5% methyl ethyl ketone and a small amount of 2-naphthalenesulfonic acid.

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Claims (1)

Claims Y is an alkyl group with 1-4 carbon atoms, a halogen atom or a trifluoromethyl group, Z represents a hydrogen atom, a halogen atom, an alkyl group with 1-4 carbon atoms, an alkoxy group with 1-4 carbon atoms or a monosubstituted alkyl group, those as substituents are a halogen atom or an alkoxy group has 1-4 carbon atoms, R _{1 is} a straight-chain or preferably branched alkyl group with 1-6 carbon atoms, a cycloalkyl group with 4-6 carbon atoms, a haloalkyl group with 1-4 carbon atoms or an alkoxyalkyl group, the alkyl part of which has 1-4 carbon atoms and the alkoxy part of 1-4 carbon atoms and R ₂ denotes a hydrogen atom or one of the groups R-, by nitrating the corresponding N-alkylated aniline, characterized in that jaan uses a nitrating agent containing three components which contains H ₂ O, H ₂ SOj and HNO ^ as components and one within has the following composition: 60% HNO ₃ , .8 IH ₂ SO ₄ , 409883/1416 ** ORIGINAL INSPECTEQ 32% H ₂ Oj 50% HNO ₃ , 35% H ₃ SO ₄ , 15% H ₃ O; 2% HNO3, ^68% H ₃ SO ₄ , 30% H ₂ O; 2% HNO ₃ , 20% H ₃ SO ₄ , 78% H ₃ O; and operates at a temperature in the range from 0 ^° C to 70 ^{° C.} 2. The method according to claim 1, characterized in that the composition of the nitrating agent is within the limits given by the following values: 45% HNO ₃ , 19% H ₃ SO ₄ , 36% H ₃ O; 45% HNO ₃ , 36% H ₃ SO ₄ , 19% H ₃ O; 20% HNO ₃ , 52% H ₃ SO ₄ , 28% H ₃ O; 20% HNO ₃ , 27% H ₃ SO ₄ , 53% H ₃ O. ' 3. The method according to claim 2, characterized in that it is carried out at a temperature in the range from 35 ⁰ C to 60 ⁰ C. 4. The method according to claim 1, characterized in that one the reaction mixture formed by treatment with 1 mole of concentrated hydrochloric acid and 1 mole of sulfamic acid denitrosed per mole of N-nitroso compound present. 5. For the process of claim 1 suitable N-alkylated Aniline of the general formula CH ₃ in the R _{1 is} a branched-chain alkyl group with 4 or 5 carbon atoms, selected from the group comprising the sec-butyigruppe, the! »- methylbu ^ yigruppe and the j -ethylpropyl group and; R, and B ₁ , hydrogen atoms, or .nitro groups mean, with the measure 'that R ₃ and R ₃ do not represent nitro groups at the same time. 409883 / U16 qWGUW- JNSPECTEO 6. Process for the preparation of compounds of the general formula HNR _x CH 3 i in the R _{1 is} a branched-chain alkyl group having 4 or 5 carbon atoms selected from the group comprising the sec-butyl group, the 1-methylbutyl group and the 1-ethylpropyl group, and R and Rc denote hydrogen atoms or nitro groups, with the proviso that the groups R. and R ₅ do not simultaneously denote hydrogen atoms, these compounds being suitable for the process of claim 1, characterized in that an N-alkylated aniline according to claim 5 reacted with concentrated nitric acid. 7. Process for the preparation of an N-alkylated aromatic amine of the general formula H ^ ^ R ₁ in the Typically a cycloalkyl group with 3-6 carbon atoms, a secondary alkyl group with 3-8 carbon atoms, optionally can be simply substituted with a halogen atom or an alkoxy group with 1 to 4 carbon atoms, R _{2 represents} a hydrogen atom, a halogen atom, an alkoxy group having 1 to 4 carbon atoms, an alkyl group having 1 to 4 carbon atoms or a monosubstituted alkyl group 409883/141 6 OBlSINAL WSPECTED 1 to 4 carbon atoms with a halogen atom as a substituent or an alkoxy group having J to 4 carbon atoms contains, and R _{3 represents} a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having Λ to 4 carbon atoms, a trifluoromethyl group, a methylsulfonyl group or a halogen atom which is suitable for the nitration process of claims 1 and 6, by reacting an aromatic amine of the general formula in which R ₂ ^{un (} ^ ^R 3 have the meanings given above, with hate substance in the presence of a noble metal catalyst and a ketone, characterized in that a promoter acid with a pKa value between 0.3 and 2.0 is used in the reaction . 409883 / U16 ORIGINAL INSPECTED