DE968273C - Process for the preparation of trisubstituted ureas - Google Patents

Description

Process for the preparation of trisubstituted ureas The invention concerns the production of -a new class of organic nitrogen compounds, namely of trisubstituted ureas.

This new class of triple-substituted ureas is represented by the formula in which R is a haloaryl radical and R and R "are monovalent aliphatic or cycloaliphatic radicals. Above all, ureas come into consideration in which R is a halophenyl and R 'and R" are monovalent saturated aliphatic hydrocarbon radicals, in particular alkyl radicals, i.e. N- Halophenyl-N ', N'-dialkyl-ureas.

The preparation of the urea derivatives is illustrated by the following general equation, according to which a haloaryl isocyanate RNCO (R = haloaryl radical) is reacted with a secondary aliphatic alkyl or cycloaliphatic amine of the formula HN ru, where R 'and R "are have the above meaning: 0 / R'll / R RNCOtHN -> R-NH-C-N7 A suitable process consists in adding dropwise the haloaryl isocyanate to the secondary amine at a temperature of from 100 to 100 ° C., preferably from 25 to 75 ° C., which is preferably used in a molar excess of 10 to 200% over the isocyanate and in an inert liquid medium, e.g., dry dioxane, dry benzene, etc., is dissolved or suspended, and the reaction continues until it is complete.The reaction is usually complete in a relatively short time, usually in a maximum of 2 hours, 2 to 20 parts of the inert reaction medium to 1 part of the secondary aliphatic amine are generally sufficient.

The urea derivative obtained can be purified by crystallization, extraction or other appropriate measures can be obtained, which largely depends on whether the urea is solid or liquid and the nature of the reaction medium used.

For example, when using dioxane or another inert water-soluble reaction medium can be solid urea derivatives with sufficient Degree of purity usually by cooling or diluting the reaction mixture with Water and filtering off the precipitated urea derivative can be obtained. If necessary, further purification by recrystallization can, mostly from dioxane or benzene or a mixture of these solvents.

The haloaryl isocyanates used as starting materials can according to known processes (cf. Vittenet, Bull. Soc. Chim. 3121, 586, 954 [1899]; Organic Synthesis, Collective Vol. II, 453 and U.S. Patent 2,428,843). One heated z. B. by reacting a primary haloarylamine with phosgene in the presence of a suitable solvent or reaction agent at ordinary temperature available haloarylcarbamic acid chloride.

In the following examples, parts mean unless otherwise specified is, parts by weight.

Example I In a solution of 36.5 parts of diethylamine in 258 parts 77 parts of p-chlorophenyl isocyanate were added dropwise to dry dioxane with evolution of heat stirred in. The temperature is kept at 20 to 300 ° C. After the reaction mixture has cooled down the solid white crystalline product which has separated out is filtered off at 1500.degree. C. and dried in a vacuum drying cabinet at 30 mm Hg and 50 ° C.

The N- (p-chlorophenyl) -N ', N'-diethylurea thus obtained melts at II 6.5 to 1170 C; this was 80 parts. Another amount of the above urea product from melting point II6 to II7 ° C by pouring the filtrate into 500 parts of water, The resulting precipitate is filtered off and dried. The entire yield is 98 01o of theory.

Example II A solution of 500 parts of p-chlorophenyl isocyanate in 102 parts of dry dioxane is added to a stirred solution of 262 parts of diethylamine added dropwise in 507 parts of dry dioxane at a sufficient rate. To When the addition is complete, stirring is continued until the temperature of the reaction mixture is reached has fallen to 25 ° C. The separated white crystals are filtered off, washed with water and dried at 500 ° C. in a vacuum drying cabinet at 30 mm Hg. The yield of N- (p-chlorophenyl) -N ', N'-diethylurea melting at II6.5 to II7 ° C amounts to 596 parts.

Another II6.8 parts of this urea with a melting point of In5.5 to 1160 C become when the filtrate is poured into 2000 parts of water, filtered off and dried obtained from the resulting precipitation.

Example III A solution of 19.5 parts of m-fluorophenyl isocyanate is left in 6I parts of dry dioxane drop by drop in a stirred solution of 2I Parts of di-n-butylamine run in 5I parts of dry dioxane. Thereby finds a instant heat development takes place. The speed of addition is regulated in such a way that that the temperature did not rise above 35 ° C. After everything has run in, the The reaction mixture was stirred for a further 20 minutes and then poured into 1000 parts of water. The resulting precipitate is separated off by filtering, washed with water and dried in a vacuum drying cabinet below 30 mm Hg at 250 ° C. There are 36 parts N- (m-fluorophenyl) -N ', N'-di-n-butylurea obtained (95 01o of the theoretical Yield).

F 70.5 to 7I "C.

Example IV A solution of 57.5 parts of p-chlorophenyl isocyanate in 51 parts of dry dioxane slowly becomes 74 parts of dicyclohexylamine in 102 parts dry dioxane added with stirring, the temperature of this exothermic Maintains reaction at 25 to 35 ° C. After mixing the reactants, stir the reaction mixture is kept for 1 hour and then poured into 1000 parts of water.

The resulting white N- (p-chlorophenyl) -N ', N'-dicyclohexylurea is filtered off, washed and dried in a vacuum drying cabinet at 30 mm Hg and 50 ° C. It melts at 183 to 186 "C. Recrystallization from hot benzene yields 103 parts (86% of the theoretical yield) of a white crystalline product from melting point 184.5 to 185 "C. Example V A solution of 19.2 parts of p-chlorophenyl isocyanate in 5I parts of dry dioxane was slowly stirred at 25 to 35 ° C A solution of 33 parts of di-n-octylamine in 102 parts of dry dioxane was added. At the Mixing the reactants releases heat. When the reaction is complete, pour the mixture in 1000 parts of water, whereupon an oil separates. This oil will etherified, the essential extract over anhydrous magnesium sulfate dried and filtered to remove the desiccant. The solid white body which remains after the ether has been removed is stored in a vacuum drying cabinet at 25 ° C dried at 30 mm Hg. 49.5] parts of white N- (p-chlorophenyl) melting at 36 to 37 ° C N ', N'-di-n-octylurea are obtained in this way.

Example VI 30.6 parts of o-chlorophenyl isocyanate were added dropwise to a solution of 16 parts of diethylamine in 258 parts of dry dioxane with stirring admitted.

When the reactants are touched, heat is released; the temperature is kept at 25 to 35 ° C. When pouring the reaction mixture into 500 parts of water A light-colored oil separated out, which was extracted with diethyl ether and its ether extract then dried over anhydrous magnesium sulfate. Its distillation yielded a fraction (37 parts) of N- (o-chlorophenyl) -N ', N'-diethyl urea.

The following were represented analogously: N- (m-fluorophenyl) -N ', N'-diethylurea; F.go, 5 to 91 ° C, yield 87.5%. N- (o-chlorophenyl) -N ', N'-dimethylurea; F.94.1 to 95.4 ° C, yield 89%. N- (o-chlorophenyl) -N ', N'-diisopropylurea; F.75 to 75.5 ° C, yield 9801 ,. N- (m-chlorophenyl) -N ', N'-dimethylurea; F. 1443, to 144.8 ° C, yield 96.5%.

N- (m-chlorophenyl) -N ', N'-diethylurea; 89.5-90 ° C, yield 99 01o. N- (m-chlorophenyl) -N ', N'-diisopropylurea; 123.5-124.5 ° CF, yield 100%. N- (m-chlorophenyl) -N'N'-dicyclohexylurea; M.p. 166.5-167 ° C, yield 100%. N- (p-chlorophenyl) -N ', N'-dimethylurea; M.p. 169.8-170.4 ° C, yield 85%. N- (p-chlorophenyl) -N'-methyl-N'-ethylurea; Mp 149-149.5 ° C, yield 87%. N- (p-chlorophenyl) -N ', N'-diisopropylurea; 152.4-153.2 ° C, yield 84%.

N- (p-chlorophenyl) -N'N'-di-n-butyourea; M.p. 129 to 129.5 ° C, yield 100%. N- (p-chlorophenyl) -N ', N'-diallylurea; 77.5-78 ° C, yield 98,010. N- (2,4-dichlorophenyl) -N ', N'-diethylurea; 50 to 52.50 C, yield 84010.

N- (2, 4, 6-trichlorophenyl) -N ', N'-diethylurea; F. 151.5 to 152 C, yield 950/0. N- (2,4,6-trichlorophenyl) -N ', N'-di-n-butylurea; F. 88.5 to 892 ° C, Yield 96%. N- (4-chloro-1-naphthyl) -N ', N'-dimethyl drug; 149.5-150.5 ° C, 98% yield. N- (4-chloro-1-naphthyl) -N ', N'-diethyl urea; M.p. 145.5-146 ° C, yield 96.5%.

N-p-bromophenyl) -N ', N'-diethylurea; F. 1210 C.

Yield 81%. N- (p-bromophenyl) -N ', N'-di-n-butylurea; 123 ° C, Yield 95%. N- (p-Jodphenylj-N ', N-dimethylurea; mp 185.5 to 186 ° C.

Yield 95%. N- (p-iodophenyl) -N ', N'-diethylurea; F. 118 to 118.5 ° C, Yield 99%. N- (p-iodophenyl) -N ', N'-di-n-butylurea; M.p. 110-111 ° C, yield 98%.

This invention is not limited to the particulars described in the examples Ureas restricted. However, preference is given to ureas, which are halogenated Aryl radicals containing one or two nuclei, such as. B. halogenated Phenyl, tolyl, xylyl, naphthyl or methylnaphthyl radicals. Particularly preferred Urea are those with a halophenyl radical containing 1 to 3 halogen substituents contains.

As the examples show, the halogen can be fluorine, chlorine, bromine or Be iodine.

The two monovalent aliphatic hydrocarbon radicals, which adhere to the same nitrogen atom of the ureas according to the invention are primarily saturated aliphatic hydrocarbon radicals and can be the same or different Be radicals with I to 18 or more carbon atoms, in addition to those in the examples also mentioned oleyl, dodecyl, octadecyl, methylcyclohexyl and decahydronaphthyl radicals be considered.

The preferred ureas are those in which the monovalent ones aliphatic hydrocarbon radicals I contain to 8 carbon atoms and preferably are saturated. Those ureas in which the monovalent aliphatic hydrocarbon radicals are acyclic, especially alkyls and contain from 1 to 4 carbon atoms the special advantage.

The ureas according to the invention are mostly colorless, crystalline and practically odorless solids, which are not in water and cold benzene or only slightly soluble, but generally in dioxane, acetone, ethyl acetate, ethyl alcohol and hot benzene are appreciably soluble. Those ureas which are long-chain aliphatic Contain hydrocarbon groups, are usually oils and also noticeably oil-soluble, z. B. in mineral oils.

The new urea derivatives regulate plant growth Properties unL are particularly valuable for weed control because they are exceptional effective weed killers, especially for combating the hitherto highly resistant ones Grasses, such as Agropyron repens, Cyperas rotundus, and Cynodon dactylon, are.

In addition, some of the new ureas also have insecticides and bacteriostatic properties. They are also valuable chemical intermediates. They can be nitrated, sulfonated or transformed into the N-methylol derivatives, which are modifiers for urea-formaldehyde polymers.

Claims (1)

PATENT CLAIM: Process for the production of trisubstituted ureas of the formula R-N H-C O-N R'R ", where R is a haloaryl radical and R 'and R" are aliphatic or mean cycloaliphatic radicals, characterized in that one is a haloaryl isocyanate of the formula RN: CO, especially p-chlorophenyl isocyanate with a secondary amir Formula HN R'R ", in particular with diethyl or dimethylamine, is implemented. Considered publications: Houben-Weyl, Methods of the org. Chemie, 1941, Vol. 4, p. 39; Reports of the German chem. Ges. 17 (1884), 3033; 34 (1991), 459; Biochem. Journ. 30, 1921 (1936); Botanical Gazette 107 (1946), No. 4, p. 476.