DE2263853A1 - N-(2,4-dihalo-s-triazin-6-yl)ureas prepn - by hydrolysis of 2,4-dihalo-6-cyanamino-s-triazines - Google Patents

Abstract

Cpds. of formula (I; X=CONH2): (where Hal is Cl, F or Br (pref. Cl); Ris H (prefd.) aryl, aralkyl, cycloalkyl or alkyl) are prepd. by treating (I;X=CN) with a practically anhydrous acid, pref. H2SO4, pref. at -20 to +50 degrees C, partially hydrolysing the reaction mixt. with H2O (pref. by pouring onto crushed ice or into H2O at 0-10 degrees C), and sepg. (I).

Description

Process for the preparation of N- (2,4-DihaloFen-striazin-6-yl) -ureas.

The present invention relates to a process for the preparation of 2,4-dihalo-6-ureido-s-triazines of the formula where Hal is chlorine, fluorine or bromine and R is hydrogen or an aryl, aralkyl, cycloalkyl or alkyl radical, which is characterized in that compounds of the formula treated with practically anhydrous acid and then the reaction mixture is partially hydrolyzed with water and the resulting 2,4-dihalo-6-ureido-s-triazine is separated off.

Such compounds have hitherto been made, for example, from N- (2,4-dihalogen-s-triazin-6-yl) isocyanates produced by reaction with ammonia. Furthermore, through implementation of 2,4-dichloro-6-isocyanodichloro-s-triazine with primary or secondary amines Urea produced (Japanese Patent No. 504,790).

These procedures have the disadvantage that they are difficult to access Products run out of cyanuric chloride in complex, complex synthesis routes must be made.

In contrast, the 2-N-cyanamino-4,6-dihalogenotriazine, which is used as the starting material in the present invention, easily Way in a one-step process from cyanuric chloride or the corresponding bromine or produce fluorine compounds and disodium cyanamide (Belgian patent No. 757 602).

Dihalotriazines containing a substituted N -cyanamino group, e.g. an N-cyananilido group, are converted by reacting one mole of trihalotriazine, especially cyanuric chloride, made with 1 mole of a substituted cyanamide.

The substituted cyanamides are obtained e.g.

according to the information in Houben-Weyl, "Methods of Organic Chemistry", Georg Thieme Verlag, Stuttgart 1952, Vol. 8, p. 17.

The 2,4-dihalotriazines obtained with substituted N-cyanoamino group and their manufacturing processes are new and are used in the present application also claimed. As substituents of the cyanoamino group there are aryl, in particular Phenyl, aralkyl, especially benzyl, cycloalkyl, especially cyclohexyl radicals in question, as well as alkyl radicals, especially those with 1 to 4 carbon atoms.

According to this process, particularly easily accessible and technically on the most important are the N- (2,4-dichloros-triazin-6-yl) ureas, especially the outside urea carrying no further substituents to the dichlorotriazinyl radical.

Strong protonic acids are used as the acid, preferably practical anhydrous sulfuric acid; this also serves as a solvent. It suit sulfonic acids, e.g. CH3SO3H.

The reaction is very simple to carry out: the 2,4-dihalo-6-cyanaminotriazine is dissolved in concentrated, preferably 98 to 10% strength sulfuric acid.

The temperature should preferably be between -20 and + 500C. To the After hydrolysis, the mixture is poured onto ground ice or into well-chilled water. The product that separates out is filtered off as quickly as possible.

The reaction temperature during the hydrolysis is preferably between 0 and 100C. In the present case, a considerable excess is used of acid as this serves as a solvent at the same time. It is but, in order to avoid a large excess of acid, it is also possible to use an anhydrous one Use solvents, e.g. formic acid, acetic acid or benzene, the latter but only if sulfuric acid is not used.

The deposition of the reaction product can optionally still be carried out in The way to be completed, that you can the ground ice or well-chilled Add a salt to the water, e.g. cooking or Glauber's salt.

The deposited reaction product is separated off by filtration, washed and dried.

Instead of hydrolyzing the product dissolved in sulfuric acid with water, you can also do the work-up in such a way that you do it with alcohol Imioether converts, from which the urinary peat is then formed with water can.

In the example below, the parts mean unless otherwise is indicated, parts by weight, the percentages percentages by weight, and the temperatures are given in degrees Celsius. The relationship between parts by weight and parts by volume is the same as between grams and cubic centimeters.

Example.

10 parts (0.053 moles) of 2-N -cyanamino-4,6-dichloro-1,3,5-triazine with stirring within 15 minutes at 0 to 5 ° in 50 parts by volume of 100% sulfuric acid registered. The solution is stirred for 90 minutes at 0 ° and then poured into a mixture of Pour 250 parts of ice and 25 parts of Glauber's salt. The precipitate is filtered off and washed with the following ice-cold liquids: 100 parts by volume of water, 100 parts by volume of water, containing 2G parts of crystalline sodium acetate, 100 parts by volume Water, 50 parts by volume acetone. After drying (room temperature, 12 mm Hg, 16 hours) 6.3 parts of 2,4-dichloro-6-ureido-1,3,5-triazine are obtained (yield: 57.5%). The elemental analysis gives: C: 23.6%, H: 1.8X, C1: 30.5X, N: 32.0 (calculated values for C4H3C12N50: C: 23.10%, H: 1.45%, Cl: 34.09%, N: 33.67%).

Claims (7)

Patent to Lorriuhc. 1. Process for the preparation of 2,4-dihalo-6-ureido-s-triazines of the formula where Hal is chlorine, fluorine or bromine and R is hydrogen or an aryl, aralkyl, cycloalkyl or alkyl radical, characterized in that compounds of the formula treated with practically anhydrous acid and then the reaction mixture is partially hydrolyzed with water and the 2,4-dihalo-6-ureidos-triazine formed is separated off. 2. The method according to claim 1, characterized in that one of Starting out triazines of the formula given, in which Hal is chlorine. 3. The method according to claims 1 and 2, characterized in that starting from triazines of the formula given, in which R is hydrogen. 4. Process according to Claims 1 to 3, characterized in that an excess of practically anhydrous sulfuric acid is used. 5. The method geäss claims 1 to 4, characterized in that the reaction by reaction with sulfuric acid at -20 to + 500C and then Carries out hydrolysis with water at low temperature. 6. The method according to claims 1 to 5; characterized in that the hydrolysis is carried out by pouring the reaction mixture onto crushed ice or in water from 0 to 100C. 7. The method according to claim 6, characterized in that the Add a salt to ice or water.