DE4127562A1 - N-mono or N,N-di:substd. urea cpds. prodn. in high yield - comprises reacting ammonium isocyanate with prim. or sec. amine in diluent, without needing to isolate free isocyanic acid - Google Patents

Abstract

Prodn. of N-mono- or N,N-di-substd. urea (I) is carried out by reacting NH4NCO with a prim. or sec. amine (I) in a diluent (III). (III) is inert under the reaction conditions and pref. is an aliphatic or aromatic (chloro)hydrocarbon, ether, alcohol or water. Alternatively, (II) also acts as (III). NH4NCO and (II) are used in equiv. amts., unless (II) also acts as (III). Either (a) (II) is added to a stirred mixt. of NH4NCO and (III) or (b) NH4NCO is stirred into (II) and opt. (III) at temps. from -20 deg. C and room temp. and reaction is completed by (a) heating to the reflux temp. of (III) or (b) increasing the reaction temp. (I) is isolated from the reaction mixt. in the usual way. ADVANTAGE - NH4NCO can be used directly, without isolating the free acid. The process is simple and gives good yields. In an example, a soln of 28.1g (0.15 mole) dodecylamine in CHCl3 was added to a suspension of 10.8g NH4NCO (83%; 0.15 mole) in 90 ml CHCl3 at room temp. The mixt. was stirred for 1 hr, then heated 2 hr. under reflux. After cooling, the ppte. was filtered and dried, giving 33.5g dodecylurea (98% of the theory), m.pt. 102-105 deg. Cs ad

Description

The present invention relates to a method of manufacture treatment of N-mono- or N, N-disubstituted ureas by conversion of ammonium isocyanate with primary or secondary amines.

The production of N-mono- or N, N-disubstituted urea fen by reacting isocyanic acid z. B. using acid addition from potassium or sodium isocyanate is released with primary or secondary amines are known and for example in Houben-Weyl, Methods of Organic Chemistry, Extension and follow-up volumes to the fourth edition, volume E4, pages 362 to 364 described. A detailed example of such an order setting is in Organic Synthesis, Vol 31 (1951), pages 9 to 11 where the reaction of p-bromoaniline with Na trium isocyanate in glacial acetic acid / water to p-bromophenylurea is written. In EP-A-03 33 350 the preparation is aromatic shear bis-dialkylureas by reaction of an aromatic Diamines with isocyanic acid, which are acidified by potassium, Na trium or silver isocyanate is described.

It has now been found that primary or secondary amines are not only with isocyanic acid, but also with a salt of isocyanate acid, namely with ammonium isocyanate to N-mono- or N, N-disub substituted ureas can be implemented. Unexpected wise, the isocyanic acid from the ammonium isocyanate not be released by adding acid.

The invention therefore relates to a method for the production lung N-mono- or N, N-disubstituted ureas, which thereby is characterized in that ammonium isocyanate in a dilution is reacted with a primary or secondary amine.  

Ammonium isocyanate is produced, for example, by rapid gasification sen of urea and quenching the reaction gases, for example after US-A-27 12 491 or when spraying molten urea in gaseous ammonia at high temperatures and quenching the reaction mixture, for example according to US-A-27 12 492 and can be made this way.

Such compounds are among primary and secondary amines to understand that have one or more amino groups. they can optionally by further, under the reaction conditions Inert groups may be substituted. examples for this are aliphatic, cycloaliphatic or cyclic amines, such as Me thylamine, ethylamine, hexylamine, hexadecylamine, isopropylamine, Isobutylamine, isooctylamine, methylethylamine, cyclohexylamine, Pyrrolidine, pyrrole, piperidine, morpholine or dimethylamine, Diethylamine, diisopropylamine, ethylenediamine, hexamethylenedi amine, 4,4′-diaminodicyclohexylmethane or aromatic amines, such as aniline, nitroaniline, chloraniline, tolylamine, benzylamine, Naphthylamines, phenylenediamines, toluenediamines, 4,4'-di aminodiphenylmethane.

To carry out the method according to the invention, either Ammonium isocyanate in one under the reaction conditions submitted thinner, stirred and with a primary or secondary amine or the primary or secondary Amine is in a Ver under the reaction conditions inert diluent, or, if the amine is liquid, without additional Liches submitted further diluent, the amine can also serve as a diluent, stirred and mixed with ammonium isocyanate.

Examples of inert diluents are aliphatic Hydrocarbons such as pentane, hexane, heptane, aromatic Hydrocarbons such as benzene, toluene, xylene, halogenated aliphatic hydrocarbons, such as methylene chloride, chloro form, carbon tetrachloride, ethyl chloride, ethylene chloride, ha logenated aromatic hydrocarbons, such as chlorobenzene, Trichlorobenzenes, ethers, such as diethyl ether, diisopropyl ether,  Dibutyl ether, ethyl methyl ether, dioxane, tetrahydrofuran, Dimethoxyethane, carboxamides, such as dimethylformamide, N- Methyl pyrrolidone, alcohols such as methanol, ethanol, diisopropyl alcohol, as well as water or mixtures of such diluents in question. Aliphatic and aromatic carbons are preferred hydrogen, halogenated, aliphatic or aromatic Hydrocarbons, ethers, alcohols and water, especially be n-hexane, chloroform, chlorobenzene, dioxane and Water.

Ammonium isocyanate can be used as such, or together with an un ter inert to the reaction conditions as described above liquid diluent, the primary or secondary amine as such, gaseous or liquid, or together with one inert under the reaction conditions as described above gaseous or liquid diluents can be added.

The addition takes place at temperatures of about -20 ° C to Boiling point of the diluent used, preferably at Temperatures from about -10 ° C to room temperature, especially be preferably at room temperature.

The amine is used in an equivalent amount or in an excess shot added to the ammonium isocyanate. But it can also be useful be moderate to add ammonium isocyanate in excess to the To improve the course of the reaction. Except where that Amine is used simultaneously as a diluent Ammonium isocyanate and the amine preferably used in an equivalent manner.

After the addition of the amine or the ammonium isocyanate has ended is used to complete the reaction at temperatures up to to the reflux temperature of the diluent used, be preferably only at room temperature and then at temperatu ren up to the reflux temperature of the diluent used stirring. The reaction may also take place un ter pressure, whereby pressures up to 20 bar can be applied.  After cooling, the compound formed crystallizes out the diluent and is filtered off, or the Ver fertilizer and, if applicable, volatile components of the The reaction mixture is evaporated. If necessary, can on Liche way such. B. by recrystallization, distillation, Chromatography, further purification can be done. Should have formed urea as a by-product of what occurs can, depending on the nature of the used urea Diluent precipitate out as a solid and, if necessary by filtering, recrystallization or chromatographic Methods are removed in the usual way.

In a preferred embodiment, ammonium isocyanate is in a diluent which is inert under the reaction conditions dissolved or suspended and at room temperature with stirring the equivalent amount of primary or secondary amine with the same inert diluent. To The addition is completed to complete the reaction Stirred room temperature and to the reflux temperature of used diluent heated. After cooling down the precipitate is filtered off and, if necessary, um crystallized. When using water as a diluent the reaction product can also be obtained directly from the reaction solution can be recrystallized after dilution with water. Falls after no reaction from the reaction, the solvent is removed evaporated and the residue is crystallized and given if recrystallized or purified by chromatography.

In another preferred embodiment, a liquid primary or secondary amine at room temperature simultaneously submitted as a reactant and as a diluent and with Ammo nium isocyanate added with stirring. After the addition is complete the reaction mixture to complete the reaction stirred at room temperature and then at elevated temperature. When the reaction has ended, the amine is distilled off or chro matographically removed and the residue if necessary Crystallize and recrystallize or chromatographically cleaned.  

The process enables simple production of N-mono- or N, N-disubstituted ureas from ammonium isocyanate in good yields and therefore represents an enrichment of technology represents.

Example 1

10.8 g of ammonium isocyanate (83%) (0.15 mol) were dissolved in 90 ml Chloroform suspended, with 28.1 g (0.15 mol) of dodecylamine, ge dissolves in chloroform at room temperature, ge 1 hour stirred and then heated to reflux for 2 hours. After cooling, the precipitate was filtered off and dried.

33.5 g of dodecylurea were obtained, which is 98% of theory obtained with a melting point of 102 to 105 ° C.

Example 2

In the manner described in Example 1, but under Use 14.9 g of cyclohexylamine (0.15 mol) instead of Do. decylamine, were 20.1 g of cyclohexylurea, which is 94% of the Get theory.

Example 3

In the manner described in Example 1, but under Use 8.9 g of isopropylamine (0.15 mol) instead of Do. decylamine, were 13.7 g of isopropyl urea, which is 89% of the Get theory.

Example 4

In the manner described in Example 1, but under Use 4.5 g of ethylenediamine (0.075 mol) instead of Do. decylamine, were 6.1 g of ethylene diurea, which is 55% of the Get theory.

Example 5

In the manner described in Example 1, but under Use 14.0 g of aniline (0.15 mol) instead of dodecylamine and Water instead of chloroform, the reaction product after completed reaction directly in the reaction mixture after addition was recrystallized from water, 4.9 g of phenyl urine substance, that is 24% of theory with a melting point of Get 145-148 ° C.

Example 6

In the manner described in Example 1, but under Using 14.0 g of aniline (0.15 mol) instead of dodecylamine, were 7.6 g of phenylurea, which is 37% of theory obtained a melting point of 145-148 ° C.

Example 7

18.6 g of aniline (0.2 mol) were added with stirring at room temperature 13.3 g of ammonium isocyanate (90%) (0.2 mol) were added. The Reaction mixture was there for one hour at room temperature and there after 5 hours at 55 to 60 ° C. After the reak has ended tion, the excess aniline was distilled off and the back stood recrystallized from water.  

12.7 g of phenylurea, which is 47% of theory, obtained with a melting point of 145-148 ° C.

Example 8-9

20 g of ammonium isocyanate (90%) (0.3 mol) were in 200 g Diluent suspended or dissolved at room temperature and with a solution of 18.0 g 1,6-diaminohexane (0.15 mol), dissolved in the same diluent with stirring. The reaction mixture was at room temperature for 1 hour and 5 Stirred at 55 to 60 ° C for hours and cooled. The fancy The precipitate was filtered off, recrystallized from water and dried.

The diluents listed in Table 1 were used Diluent used. When using water as The reaction mixture became diluent after completion Reaction mixed with 600 ml of water and the failed never the recrystallized therein.

The yields listed in Table 1 were Get hexane diurea with a melting point of 202-205 ° C ten.

In the manner described above, but with the addition of 32.2 g of benzylamine (0.3 mol) instead of 1,6-diaminohexane the yields of benzylurea given in Table 1 hold.

Table 1

Example 10

18.0 g of 1,6-diaminohexane (0.15 mol) was pre-dissolved in 200 ml of water placed and heated to a) 50 ° C and b) 100 ° C with stirring. 20.0 g of ammonium isocyanate (90%) (0.3 mol) was ge in water dissolves and at the specified temperatures with stirring dripped. When the reaction was complete, the reaction mixture mixed with 600 ml of water and the precipitate recrystallized, suction filtered and dried.

A) 45% and b) 47% yield of theory 1.6 Get hexane diurea with a melting point of 202-205 ° C ten.

Example 11

14.11 g of ammonium isocyanate (85%) (0.2 mol) were dissolved in 200 ml of Suspended hexane and dissolved with 48.3 g of dioctylamine (0.2 mol) added in 200 ml of n-hexane. When the addition was complete, one Stirred for one hour at room temperature and then two Heated to reflux for hours. After cooling the reaction Some urea precipitated out of the mixture and was filtered off. The Filtrate was distilled at 100 ° C, 0.03 to 0.04 mbar subjected to volatiles removal.  

51.0 g of N, N-dioctylurea were obtained, which is 90% of the Theory, obtained in the form of a yellowish oil.

Claims (8)

1. A process for the preparation of N-mono- or N, N-disubstituted ureas, characterized in that ammonium isocyanate is reacted in a diluent with a primary or secondary amine. 2. The method according to claim 1, characterized in that as Diluent iner under the reaction conditions diluent is used. 3. The method according to any one of claims 1 or 2, characterized records that an aliphati as an inert diluent shear or aromatic hydrocarbon, a chlorinated, aliphatic or aromatic hydrocarbon Ether, alcohol or water is used. 4. The method according to claim 1, characterized in that the primary or secondary amine simultaneously as a diluent medium is used. 5. The method according to claim 1, characterized in that Ammo nium isocyanate and the primary or secondary amine in equivalent amounts are used, provided the amine is not used as a diluent at the same time. 6. The method according to claim 1, characterized in that Ammo submitted nium isocyanate in an inert diluent and with stirring at temperatures from -20 ° C to room temperature mixed with a primary or secondary amine and is reacted, whereupon the temperature is completed constant reaction up to the reflux temperature of the placed, inert diluent is increased.   7. The method according to claim 1, characterized in that a primary or secondary amine with or without inert diluent Nmittel presented and with stirring at temperatures of -20 ° C to room temperature with ammonium isocyanate and reacted, whereupon the reaction temperature is increased to complete the reaction. 8. The method according to any one of claims 1 to 7, characterized records that the N-mono- or N, N-disubstituted ized urea in the usual way from the reaction mixture is isolated.