DE2064309A1 - 2-methylmercapto-4,6-diamino-s-triazines prepn - from corresp 2-halo cpds - Google Patents

Abstract

Cpds. of formmula (I): (where R is 1-5C alkyl or CH3O(CH2)5), which are inters. for herbicides, are produced by (a) heating sulphur with calcium hydroxide in aqs. soln. to >60 degrees C; (b) slowly adding a corresp. 2-halo(pref. 2-chloro-)4,6-diamino-s-triazine, opt. in a water-contg. organic solvent; and (c) methylating the reaction product in a conventional manner.

Description

Process for the preparation of N-substituted 2-methylmercapto-4,6-bis-amino-1,3,5-triayins The invention relates to a process for the preparation of N-substituted 2-methylmercapto-4,6-bis-amino-1,3,5-triayins by reacting corresponding N-substituted 2-chloro-4,6-bis-amino-1,3,5-triazines With sulfur and calcium hydroxide.

It is already known - SH or - SCH3 - groups containing 4,6-bis-amino-1,3,5-triazines to produce, preferably a chlorine atom on the corresponding triazine by the named groups is replaced.

The German Auslegeschrift 1 191 382 @ describes the implementation of Halotriazine with thichurea as the compound introducing the mercapto group. However, this method is burdened by a very large amount of equipment and considerable Chemical consumption.

From the German Auslegeschrift 1 224 747 is a method for production of N-substituted 2-alkylmercapto-4,6-bisamino-1,3,5-triazines by reaction of the corresponding 2-halo-4,6-bis-amino-1,3,5-triazines with sodium sulfide, sulfur and sodium hydroxide in the presence of an emulsifier known, which from economic Reasons could not gain any meaning so far.

The invention is based on the object of a particularly economical and simple process for the preparation of N-substituted 2-methylmercapto-4,6-bis-amino-1,3,5-triazines to accomplish.

This object was achieved according to the invention by a process for the preparation of N-substituted 2-methylmercapto-4,6-bisamino-1,3,5-triazines of the general formula.

wherein R is an alkyl radical with 1 to 5 carbon atoms or the CH3-O- (CH2) 3 group means by heating the corresponding N-substituted 2-halo-4,6-bis-amino-1,3,5-triazines with sulfur in an aqueous alkaline solution, characterized by the combination following work steps: a) Preheating of sulfur and calcium hydroxide in aqueous Solution to a temperature above 60 ° C.

b) slow addition of the 2-halogen compound, optionally in one aqueous organic solvent, c) heating continued for several hours of the reaction mixture and d) methylation of the reaction product in a manner known per se Way, 2-chloro compound is preferably used as the 2-halogen compound A molar ratio of 2-halogen compound to sulfur has proven particularly expedient and calcium hydroxide from 1: 1.5 to 4: 1.5 to 4.

hIS solvent is water, optionally mixed with water-miscible Solvents such as B. acetone, alcohol, dioxane, used. An addition to one Such organic solvents can be useful if they are used as the starting substance used 2-halogen compound prepared in such a solvent and to be used in the process according to the invention without isolation.

The reaction mixture is brought to a temperature between about 600.degree and the reflux temperature of the solvent. The reflux temperature is preferred.

Step a) of the process according to the invention, d. H. the preheating of sulfur and calcium hydroxide in an aqueous solution expediently lasts at least 1/2 hour and preferably about 3/4 to 1 1/2 hours. This is followed by Maintaining the temperature stage b), the slow introduction of the 2-halogen compound. This substance can be in solid form or dissolved in a solvent which is with de aqueous solution is miscible, can be added. The encore usually takes a long time approximately 1 to 1 1/2 hours, but shorter or longer addition times can also be used will. After the addition has ended, stage c) follows. Here, the reaction mixture a few hours, preferably about 2 to 6 hours, further heated, preferably as in the previous stages to reflux temperature.

The subsequent methylation of the reaction product takes place in an in a known manner by adding one of the usual methylating agents. Very good Results were obtained with dimethyl sulfate as the methylating agent, which because of its ease of use and accessibility is preferred.

When using dimethyl sulfate, a reaction time of about is sufficient 1 hour at 30 to 40 ° C for complete conversion of the intermediate product obtained 2-mercapto compound into the desired 2-methyl mercapto compound. before the addition of the methylating agent, the reaction mixture is expediently cooled and filtered.

The reaction product can usually be removed by simple filtration isolate from the reaction mixture.

Isolation of the 2-mercapto compound formed as an intermediate before methylation is not required. Preferably that obtained in step c) Solution used directly for methylation. The 2-mercapto derivative can also be isolated by acidifying the solution and the precipitated mercapto derivative is separated. Acetic acid is preferably used to precipitate the 2-mercapto derivatives used.

Surprisingly, the process according to the invention works without prior application sulphurous sulphidation compounds and emulsifiers in an extremely simple manner Way by using particularly cheap raw materials for better yields than that known procedures. The obtained by the method according to the invention Products are particularly suitable for the production of herbicides.

The following examples further illustrate the invention.

Example 1 2-Methylmercapto-4,6-bis-ethylamino-1,3,5-traizin.

148 parts by weight of Ca (OH) 2 and 76.8 parts by weight of sulfur are added of 4000 parts by volume of water for about 45 minutes with stirring and reflux. 205 parts by weight of finely powdered 2-chloro-4,6-bis-ethylamino-1,3,5-triazine are then carried over the course of 180 minutes and refluxed for a further 5 hours.

The reaction mixture is cooled and filtered. Become a filtrate 200 parts by weight of dimethyl sulfate were added dropwise with stirring at 30 to 37 ° C and after The 2-methylmercapto-4,6-bis-ethylamino-1,3,5-triazine which has precipitated is after-reacting at 30 to 40 ° C. for 120 minutes filtered off, washed with water and dried.

Yield: 205 parts by volume = 94.5%, based on the triazine used. Mp = 78.9 ° C.

Example 2 2-Methylmercapto-4-i-propylamino-6-methoxy-propylamino-1,3,5-triazine.

29.6 parts by weight of Ca (OH) 2 and 15.4 parts by weight of sulfur are under Addition of 800 parts by volume of water for 1 hour. Heated with stirring and reflux. Then 52 parts by weight of finely powdered 2-chloro-4-i-propylamino-6-methoxypropylamino are added within 60 minutes -1,3,5-triazine entered and the reaction mixture 3 hours.

heated to reflux. It is then cooled and filtered. 40 parts by weight of dimethyl sulfate are added dropwise to the filtrate with stirring at 20 to 250 C, then briefly heated to 600 C and after cooling to + 5 ° the precipitated 2-methylmercapto-4-i-propylamino-6-methoxy-propylamino-1,3,5-triazine is filtered off, washed with water and dried.

Yield: 52.8 parts by weight of G 97, based on the triazine used. Mp = 68.6 ° C.

Example 3: 2-methylmercapto-4-ethylamino-6-i-propylamino-1,3,5-triazine.

29.6 parts by weight of Ca (OH) 2 and 15.4 parts by weight of sulfur are under Addition of 800 parts by volume of water about 75 ilin. heated for a long time with stirring and reflux. 43.10 parts by weight of finely powdered 2-chloro-4-ethylamino-6-i-propylamino-1,3,5-traizin are then added over the course of 60 minutes entered and the reaction mixture heated under reflux for a further 3 hours. Thereafter wira cooled and filtered.

40 parts by weight of dimethyl sulfate are added to the filtrate with stirring at 20 to 250 ° C. added dropwise and after another 60 Hin. lasting post-reaction at 30 to 400 C the precipitated 2-methylmercapto-4-ethylamino-6-i-propylamino-1,3,5-atriazine filtered off, washed with water and dried.

Yield: 44 parts by weight = 97%, based on the triazine used.

J? P, = 87.70 C.

Example 4 2-Methylmercapto-4-methylamino-6-i-propylamino-1,3,5-triazine.

29.6 parts by weight of Ca (OH) 2 and 15.4 parts by weight of sulfur are under Addition of 800 parts by volume of water for about 1 hour. Heated with stirring and reflux. 40.3 parts by weight of finely powdered 2-chloro-4-methylamino-6-ipropylamino-1,3,5-triazine are then carried over the course of 90 minutes and refluxed for a further 3 hours. The reaction mixture is cooled and filtered.

40 parts by weight of dimethyl sulfate are added to the filtrate at 25 to 28 ° C. with stirring added dropwise and after a further 60 min. Post-reaction at 30 to 40 ° C the precipitated 2-methylmercapto-4-methylamino-6-i-propylamino-1,3,5-triazine filtered off, washed with water and dried.

Yield: 41 parts by weight = 96%, based on the triacine used. Bp = 83.10 (;

Claims (4)

PATENT CLAIMS 1.) Process for the preparation of N-substituted 2-methylmercapto-4,6-bis-amino-1,3,5-triazines of the general formula where R is an alkyl radical with 1 to 5 carbon atoms or the CH3-O- (CH2) 3 group, by heating the corresponding N-substituted 2-halogen-4,6-bis-amino-1,3,5- triazines with sulfur in aqueous-alkaline solution, characterized by the combination of the following work steps: a) preheating of sulfur and calcium hydroxide in aqueous solution to a temperature above 60 ° C, b) slow addition of the 2-halogen compound, optionally in an aqueous organic solvent, c) continuing the heating of the reaction mixture for several hours and d) methylating the reaction product in a manner known per se. 2.) The method according to claim 1, characterized in that 2-halogen compound, Sulfur and Ca (OH) 2 are reacted in a molar ratio of 1: 1.5 to 4: 1.5 to 4. 3.) Method according to claim 1 or 2, characterized in that is heated to reflux temperature in steps a (, b) and c). 4.) Method according to one of the preceding claims, characterized in that that the 2-halogen compound, preferably 2-chloro compound, in the course of about 1 to 1 1/2 hours is admitted.