CS223432B1 - Substituted 5-chlor-3-oxo-2h-pyridazins and method of preparation thereof - Google Patents

Description

The present invention relates to substituted 5-chloro-3-oxo-2H-pyridazines and to a process for their preparation. The compounds can be used as intermediates in the synthesis of various insecticidal and herbicidal organic compounds.

2-Methyl-4-morpholine-5-chloro-3-oxo-2H-pyridazine is known in the literature and is prepared by reacting morpholine with 2-methyl-1,4,5-dichloro-3-oxo-2H-pyridazine. in toluene at 150 ° C [jap. Kokai 74 117,471, C.A. 83,164,218 (1975)].

Substituted 5-chloro-3-oxo-2H-pyridazines of formula I have now been found,

wherein R ¹ is C 1 -C 4 alkyl, cyclohexyl, phenyl, optionally substituted with trifluoromethyl, benzyl, R ² is C 1 -C 4 alkyl,

2-methoxyethyl, cyclohexyl, R ³ represents a hydrogen atom, a methyl group, an ethyl group or R ² and R ³ together with the nitrogen to which they are attached may form a piperidine or pyrrolidine ring.

The new compounds of formula I, wherein R ^1, R ² and R ³ are as defined above, are prepared by reaction of 4,5-dichloro-3-oxo-2H-pyridazine of the formula II

wherein R ¹ is as defined above, with an amine of formula III

R ³ \

NH /

R ² (III) wherein R ² and R ³ are as previously defined, in an organic diluent such as aromatic hydrocarbons (benzene, toluene, xylene), aliphatic, cyclic hydrocarbons (hexane, heptane, cyclohexane, cyclooctane) and the like. , at a temperature of 60 to 140 ° C by introducing into the reaction mixture consisting of the compound of formula II an inert diluent gas in the medium of an inert diluent, if its boiling point is lower than the temperature of the reaction mixture, or it is added simultaneously to the reaction mixture at room temperature.

The following examples illustrate but do not limit the scope of the invention.

Example 1

2-methyl-4-methylamino-5-chloro-3-oxo-2H-pyridazin

To 17.9 g of 2-methyl-4,5-dichloro-3-oxo-2H-pyridazine (0.1 mol) in 100 ml of toluene was added anhydrous methylamine while stirring at boiling point until 2-methyl-4 had reacted, 5-dichloro-3-oxo-2H-pyridazine. After cooling, the reaction mixture was washed with water, dried over aq. sodium sulfate and toluene were distilled off under reduced pressure. The distillation residue was purified by column chromatography.

11.6 g of a white crystalline solid are obtained, m.p. 72-74 ° C.

The structure of the substance was confirmed by spectral methods:

IR in CHCl3 (C = O) 1635 cm ^{@ -1} .

UV in CH3OH Atnax (nmi) (log):

210 (4.56), 247 (4.07), 338 (4.39).

1 H-NMR δ (ppm):

CH, 7.58 s,

NCH3, 3.73 s,

N (CH 3) 2, 3.12 s.

¹³ C-NMR .delta. (Ppm):

C = O, 159.17,

C = N, 148.30,

C, N, 112.63,

C-Cl, 129.88, (CH ₅ ) 2 N, 41.92,

CH 3 N, 40.29.

Analysis for C 6 H 8 ClN 3 O (MW: 173.59): calc .: 20.42% Cl, 24.21% N, found: 20.29% Cl, 24.0% N.

The following compounds were prepared in a similar manner:

2. 2-ethyl-4-methylamino-5-chloro-3-oxo-2H-pyridazine, m.p. 70-72 ^Q C,

3. 2-Cyclohexyl-4-methylamino-5-chloro-3-oxo-2H-pyridazine, 1.1. 111-113 ° C,

4. 2-Phenyl-4-methylamino-5-chloro-3-oxo-2H-pyridazine, 1.1. 115-117 ° C,

5. 2- (m-Trifluoromethyl) phenyl-4-methylamino-5-chloro-3-oxo-2H-pyridazine, m.p. t. 142-143 ° C,

6. 2-Methyl-4-dimethylamino-5-chloro-3-oxo-2H-pyridazine, 1.1. 28 to 29 ° C,

7. 2-Phenyl-4-dimethylamino-5-chloro-3-oxo-2H-pyridazine, m.p. t. 79-80 ° C.

Example 8

2-methyl-4-isobutylamino-5-chloro-3-oxo-2H-pyridazin

To 17.9 g of 2-methyl-4,5-dichloro-3-oxo-2H-pyridazine (0.1 mol) in 120 ml of toluene was added 14.6 g of isobutyl laminate (0.2 mol) in one portion. The reaction mixture was stirred at boiling point for 4 hours. After cooling, it was washed with water, the toluene portion was dried and the toluene was distilled off under reduced pressure. The residue was purified by column chromatography.

12.5 g of a white crystalline solid are obtained, m.p. 85-87 ° C.

Analysis for C 9 H 14 ClN 3 O (m / d: 215.67): calc. N, 19.49; Cl, 16.44. Found: N, 19.34; Cl, 16.55.

The following substances were prepared in a similar manner:

9. 2-Phenyl-4-butylamino-5-chloro-3-oxo-2H-pyridazine, m.p. t. 55 to 56 ° C,

10. 2-Phenyl-4- (2-methoxyethyl) amino-5-chloro-3-oxo-2H-pyridazine, m.p. t. 69 to 71 ° C,

11. 2-Methyl-4-cyclohexylamino-5-chloro-3-oxo-2H-pyridazine, 1.1. 48 to 50 ° C,

12. 2-Phenyl-4-cyclohexylamino-5-chloro-3-oxo-2H-pyridazine, m.p. t. 42 to 44 ° C,

13. 2-Methyl-4-pyrrolidinyl-5-chloro-3-oxo-2H-pyridazine, m.p. in. 121 ° / 26.6 Pa,

14. 2-Phenyl-4-pyrrolidinyl-5-chloro-3-oxo-2H-pyridazine, m.p. t. 92-94 ° C,

15. 2-Benzyl-4-pyrrolldinyl-5-chloro-3-oxo-2H-pyridazine, m.p. t. 85-87 ° C,

16. 2-Methyl-4-piperidinyl-5-chloro-3-oxo-2H-pyridazine, m.p. in. 133 ° C / 66.5 Pa

17. 2-Propyl-4-diethylamino-5-chloro-3-oxo-2H-pyridazine, telephone 140 ^C C / 26.6 Pa.

Claims (2)

SUBJECT Substituted 5-chloro-3-oxo-2H-pyridazines of the general formula I OF THE INVENTION wherein R ¹ is C 1 -C 4 alkyl, cyclohexyl, phenyl, optionally substituted with trifluoromethyl, benzyl, R ² is C 1 -C 4 alkyl, 2-methoxyethyl, cyclohexyl, R ³ is hydrogen, methyl, ethyl or R ² and R ³ together with the nitrogen to which they are attached may form a piperidine or pyrrolidine ring. 2. A process for the preparation of compounds of claim 1 to mark] 'learns that the 4,5-dichloro-3-oxo-2H-pyridazine of formula II wherein R ¹ is as defined above, is reacted with an amine of formula III R ² \ NH FROM R ³ (ΠΙ) wherein R ² and R ³ are as previously defined in an inert organic diluent at 60 and 140 ° C.