PL185411B1 - Method of obtaining derivatives of pyridilaminotriazine - Google Patents

Abstract

1. The method of producing derivatives of pyridil-amino-triazine with formula 3, where: R1 refers to C1-C12alkyl, C3-C6cycloalkyl or C1-C4alkoxy-C1-C6alkyl, R2 and R3 refers to hydrogen, and Z refers to -N=CH-. Characterized in that: Amino-triazinone with formula 1, where R1, R2 and R3 have the meaning indicated above, is subjected to reaction with the aldehyde with formula 4. Amino-triazinone with formula 1, where R1, R2 and R3 have the meaning indicated above, is subjected to reaction with the aldehyde with formula 4. The reaction uses the amino-triazinone with formula 1, prepared by sovolysis of the compound with formula 2, where R1, R2 and R3 have the meaning indicated above, while R4 refers to H, C1-C4alkyl, C3-C6cycloalkyl or phenyl, in the presence of gaseous hydrogen chloride, in the environment of alcohol.

Description

The present invention relates to a process for the preparation of pyridylaminotriazine derivatives of formula III.

The compounds of formula III are known useful agricultural chemical compounds, especially insecticides as described in EP-A-0 314 615. A process for the preparation of aminotriazine derivatives by solvolysis of the compound of formula 2 in the presence of aqueous HCl is described in EP-A-0 314 615. 433218.

Pyridylaminotriazine derivatives of the formula 3 where R 1 is hydrogen, C ₆ -C ₆ alkyl, C ₁ -C ₆ cycloalkyl, C ₁ -C ₄ alkoxy-C ₁ -C ₆ alkyl, R 2 and R 3 is hydrogen, and Z is -N = CH-, is prepared by the process of the invention by reacting an aminotriazinone of the formula 1, wherein R ", R 2 and R 3 are as defined above, with an aldehyde of the formula 4 in which the aminotriazinone of the formula 1 was prepared by solvolysis of a compound of the formula 2 wherein R" R2 and R3 are as defined above and R "is H, C ₁ -C ₄ alkyl, C ₃ -C 6 cycloalkyl or phenyl, in the presence of hydrogen chloride gas in an alcoholic medium.

It was surprisingly found that carrying out the solvolysis of the compound of formula 2 in the presence of gaseous hydrogen chloride allows to significantly increase the yield of the obtained compound of formula 1 (increasing the concentration of the solution after the solvolysis process) and to reduce the amount of by-products formed, which in turn allows to reduce the number of those process steps which are related to the purification of the final product and the disposal of by-products

The starting compounds of formula II are commercially available or may be prepared by known methods. Prior to preparing compounds of formula 1, it is preferable to prepare compounds of formula 2 in situ in the same or a very similar alcoholic medium to that used in the process of the invention, thus avoiding tedious isolation or separation steps.

The method can be run continuously or batchwise. The amount of nicotinic aldehyde in the aqueous medium is preferably 20-50% by weight, more preferably 25-40% by weight.

The following examples illustrate the process of the invention.

The aldehyde yield was determined by HPLC or gravimetrically by derivatization with 4-amino-6-methyl-3-oxo-2,3,4,5-tetrahydro-1,2,4-triazine, abbreviated as aminotriazinone.

185 411

Example I. Comparison of the use of aqueous versus gas HCl 6-Methyl-4-acetylamino-4,5-dihydro-1,2,4-triazin-3- (2H) -one was suspended in methanol. The slurry was heated to 45 ° C and became a clear, colorless solution. To this solution at a temperature between 45 and 50 ° C was added gaseous HCl (a) or aqueous HCl (b) over 2-3 hours. After adding about 30% gaseous HCl (a) or 50% aqueous HCl (b), the reaction mixture was seeded with 4-amino-6-methyl-3-oxo-2,3,4,5-tetrahydro-1,2,4-triazine hydrochloride. then 4-amino-6-methyl-3-oxo-2,3,4,5-tetrahydro-1,2,4-triazine continuously precipitated as the hydrochloride salt. Maximum conversion was reached after about 2 hours of stirring. The reaction mixture was adjusted to pH 5 by adding 50% NaOH solution to form free 4-amino-6-methyl-3-oxo-2,3,4,5-tetrahydro-1,2,4-triazine.

The respective theoretical yields were as follows:

Test no AND moles Methanol g HCl gas g aqueous HCl g theoretical efficiency% (and) 0.234 99 15.4 99.2 (b) 0.234 99 41.6 77.2

A = 6-methyl-4-acetylamino-4,5-dihydro-1,2,4-triazin-3- (2H) -one

Test No. (a): This test was conducted with HCl gas. The maximum conversion was greater than 99%. Free 4-ammo-6-methyl-3-oxo-2,3,4,5-tetrahydro-1,2,4-triazine was formed in an amount of 29.7 g, i.e. 14.3% by weight of the solution. This is 99.2% of the theoretical amount.

Test No. (b): Test (a) is repeated using aqueous HCl. The maximum conversion was 77.2%. Free 4-amino-6-methyl-3-oxo-2,3,4,5-tetr-Thiydro-1, 2,4-triazine was formed in an amount of 23.1 g representing a 10.3 wt% solution. This is 77.2% of the theoretical amount.

Example II. (Laboratory scale).

124.8 g of 3-cyanopyridine, 277 g of water and 72.2 g of acetic acid were mixed together in an autoclave equipped with an agitator. 14.6 g of wet Raney nickel (Ni content about 60%) in 50 g of water were added to the mixture, which was then hydrogenated under a constant hydrogen pressure of 0.1 MPa. When 110% of the theoretical hydrogen had been taken up (after about 5 hours), the stirrer was turned off and the reaction was quenched with nitrogen.

The catalyst was filtered off under argon and washed with water. After filtration, 515 g of a product solution was obtained with 20.9% 3-pyridinaldehyde as determined by HPLC. This is 85.2% of the theoretical amount. The 3-picolyl alcohol content was 0.4%, and the 3-picolylamine content was 1.5%. The aldehyde yield was found to be 84% after derivatization with aminotriazinone. The loss of nickel from the catalyst was 115 mg corresponding to about 1.3% of the total nickel content.

Example III. Preparation of 6-Methyl-4- (pyridin-3-ylmethyleneamino) -4,5-dihydro-1,2,4-triazin-3 (2H) -one.

To a suspension of 164 g of 4-amino-6-methyl-3-oxo-2,3,4,5-tetrahydro-1,2,4-triazine hydrochloride in 500 ml of methanol was added 50% NaOH solution until the pH was 6. Then 486 was added. g of a solution containing 22% pyridine-3-aldehyde in water, keeping the temperature below 70 ° C. After the addition was complete, the mixture was held at 65 ° C for two hours, then the reaction mixture was cooled to about 5 ° C, filtered and dried to afford the title compound.

185 411

MODEL 3

Publishing Department of the UP RP. Mintage 60 copies. Price 2.00 PLN.

Claims (4)

Patent claims 1. A process for the preparation of pirydyloaminotriazyny of formula 3 wherein R is Ci ^ alkyl, _C3-C6 cycloalkyl, or C ₁ -C ₄ alkoxy-C _{r C6} alkyl, R2 and R3 is hydrogen and Z is -N = CH -, characterized by reacting an aminotriazinone of formula I, wherein R "R2 and R3 are as defined above, with an aldehyde of formula IV, whereby an aminotriazinone of formula I is used prepared by solvolysis of a compound of formula II in which R "R2 and R3 are as defined above, and R ₄ is H, C, -C ₄ alkyl, C 3 -C ₆ cycloalkyl or phenyl, in the presence of gaseous hydrogen chloride in an alcoholic medium. 2. The method according to p. The process of claim 1, wherein the compound of formula 3 is prepared, wherein R 1 is C, -C 6 alkyl or C ₃ -C ₅ cycloalkyl, R 2 and R 3 are hydrogen and Z is -N = CH-. 3. The method according to p. The process of claim 2, wherein the compound of formula 3 is prepared 6-methyl-4- (pyridin-3-ylmethyleneamino) -4,5-dihydro-1,2,4-triazin-3 (2H) -one.