DE1137029B - Process for the preparation of 2- (2 ', 4'-dichloro-s-triazino) -cyclohexen-1-ols - Google Patents

Description

Process for the preparation of 2- (2 ', 4'-dichloro-s-triazino) -cyclohexen-l-ols It has been found that 2- (2', 4'-dichloro-s-triazino) -cyclohexene-l -ols of the general formula where R is an alkyl radical having 1 to 4 carbon atoms is obtained when enamines of the general formula where R has the meaning given above, R 'and R "are identical or different aliphatic radicals with 1 to 6 carbon atoms or together are members of a cycloaliphatic ring, which may also contain heteroatoms, with cyanuric acid chloride at about 10 to 45'C in the presence an inert solvent and the addition product is treated with water at about 10 to 25 ° C. The reaction proceeds according to the equation: It is surprising that such a reactive triazine with two labile chlorine atoms is formed, although water is used in the hydrolysis reaction and an amine is released.

The reaction is carried out in the presence of an inert solvent, such as B. benzene, petroleum ether, chloroform, carbon tetrachloride, carbon disulfide and nitrobenzene. The two reaction components are left on top of one another Stir initially at room temperature and then heat up for some time 30 to 45 ° C. At higher temperatures, resinification usually occurs. At lower temperatures the reaction is very slow and incomplete. Then one leaves cool again and hydrolyze the addition compound with water at temperatures between 10 and 25'C.

It can be advantageous to add small amounts to the water during hydrolysis Add glacial acetic acid, ammonium nitrate, etc. and thereby accelerate the hydrolysis.

But one can also proceed in such a way that one uses the enamines without prior Isolation from the reaction mixture of the cyclohexanones with a secondary Amine can react with the cyanuric acid chloride.

The 2- (2 ', 4'-dichloro-s-triazino) -cyclohexene-1- o1 thus obtained can z. B. obtained by evaporation of the solvent and z. B. by recrystallization getting cleaned. It can be used as a herbicide and serves as an intermediate for the production of fungicides and dyes.

The parts given in the examples are parts by weight. example 1 To a mixture of 185 parts of cyanuric acid chloride and 600 parts of chloroform a solution of 180 parts of pyrrolidinocyclohexene in 300 parts of chloroform at 20 to 25 ° C was added dropwise within half an hour. Then 3 hours at 20 Stirred up to 25'C and 11 / Z hours at 40'C. After cooling the solution will be 170 Parts of water and 15 parts of glacial acetic acid were added and the mixture was stirred at 20 ° C. for 12 hours. On that the chloroform layer is separated and evaporated in vacuo.

There remain as residue 245 parts of crude 2- (2 ', 4'-dichloro-s-triazino) -cyclohexen-l-ol, which, recrystallized from ethyl acetate, melts at 114 to 115 ° C.

The same yields are obtained when using morpholinocyclohexene. Example 2 110 parts of cyclohexanone, 110 parts of pyrrolidine, 600 parts of benzene and 30 parts of potash are stirred at 40 ° C. for 4 hours. After filtering off, the excess pyrrolidine is then distilled off via a column. To the remaining solution of pyrrolidinocyclohexene, 185 parts of cyanuric chloride are added in portions at 10 to 15 ° C with cooling over the course of one hour, then the mixture is stirred for 8 hours at 15 to 20 ° C and 2 hours at 40 ° C. Finally, 200 parts of water, in which 20 parts of ammonium nitrate are dissolved, are added and the mixture is stirred at 15 to 20 ° C. for 16 hours. The benzene layer is separated, washed with water and the benzene is distilled in vacuo. The residue is recrystallized from a benzene-petroleum ether mixture. 165 parts of pure 2- (2 ', 4'-dichloro-s-triazino) -cyclohexen-1-ol are obtained in this way. Example 3 The procedure is as in Example 2, except that 120 parts of 4-methylcyclohexanone are used instead of cyclohexanone. 115 parts of 2- (2 ', 4'-dichloros-triazino) -4-methyl-cyelohexen-1-ol of melting point 94 to 960 ° C. are obtained in this way. Example 4 A solution of 165 parts of morpholinocyclohexene in 500 parts of methylene chloride is added at 20 to 25 ° C. over the course of one hour to a mixture of 185 parts of cyanuric acid chloride in 800 parts of methylene chloride. The mixture is then stirred for 4 hours at 20 to 25 ° C. and refluxed for 2 hours. After the reaction mixture has cooled, 200 parts of water are added and the mixture is stirred at 15 to 20 ° C. for 12 hours. The methylene chloride layer is then separated off and vigorously stirred with 600 parts of water for a further 4 hours. After the methylene chloride layer has been separated off, it is evaporated on a water bath. After recrystallization of the residue from ethyl acetate, 224 parts of pure 2- (2 ', 4'-dichloro-s-triazino) -cyclohexen-1-ol are obtained.

Claims (1)

PATENT CLAIM: Process for the preparation of 2- (2 ', 4'-dichloros-triazino) -cyclohexen-l-ols of the general formula wherein R is an alkyl radical having 1 to 4 carbon atoms, characterized in that enamines of the general formula where R has the meaning given above, R 'and R "are identical or different aliphatic radicals with 1 to 6 carbon atoms or together are members of a cycloaliphatic ring, which may also contain heteroatoms, with cyanuric acid chloride at about 10 to 45 ° C in the presence an inert solvent and the addition product is treated at about 10 to 25 ° C with water.