JPH075558B2 - Pyridine-3-carboxamide derivative and plant growth inhibitor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to 1,4-dihydro-2,6-dimethyl-4-oxo-
The present invention relates to a novel compound belonging to 3-pyridinecarboxamide and a plant growth inhibitor containing the same.

(Prior Art) Conventionally, 1,4-dihydro-2,6-dimethyl-4-oxo-3
Descriptions of the compounds belonging to the pyridinecarboxamide can be found in the literature. Kato Tetsuzo Pharmaceutical Journal, 101, 40 (1981), N- (4-chlorophenyl)
-1,4-dihydro-2,6-dimethyl-4-oxo-3-pyridinecarboxamide, 1,4-dihydro-2,6-dimethyl-4-oxo-N-phenyl-1- (phenylmethyl)
-3-Pyridinecarboxamide, 1,4-dihydro-N-
(4-Methoxyphenyl) -2,6-dimethyl-4-oxo-1- (phenylmethyl) -3-pyridinecarboxamide and N- (4-chlorophenyl) -1,4-dihydro-2,6-dimethyl-4 Although four compounds of -oxo-1- (phenylmethyl) -3-pyridinecarboxamide have been reported, this reference relates to the reactivity of ketene derivatives, and to which field these compounds are used. Has not been touched. Also, Canadian Patent No. 1,115,278 (and JB Pierce et al. J. Med. Chem. 25.1
31 (1982)), there is a description of 4-pyridone compounds having an anti-inflammatory effect, and 1,4-dihydro-
2,6-Dimethyl-4-oxo-N, 1-diphenyl-3-pyridinecarboxamides, N, 1-dibutyl-1,4-dihydro-2,6-dimethyl-4-oxo-3-pyridinecarboxamide , N, 1-didodecyl-1,4-dihydro-2,6-dimethyl-4-oxo-3-pyridinecarbosamide, N- (4
-Chlorophenyl) -1-ethyl-1,4-dihydro-2,6
-Dimethyl-4-oxo-3-pyridinecarbosamide, 5
-Bromo-1,4-dihydro-2,6-dimethyl-4-oxo-N, 1-diphenyl-3-pyridinecarbosamide and 5-bromo-N, 1-bis (4-chlorophenyl-) 1,4 −
Dihydro-2,6-dimethyl-4-oxo-3-pyridinecarboxamide and the like are disclosed. In addition, JP-A-54-
Japanese Patent No. 24892 discloses cephalosporins having 5-halo-1,4-dihydro-4-oxo-3-pyridinecarboxamide as a partial structure for pharmaceutical use.

On the other hand, as a compound showing activity as a plant growth regulator, especially as a scientific mating agent, 1,4-dihydro-4-oxo-3-
Although derivatives of pyridinecarboxylic acid are known,
52-144676, JP-A-57-114573), a plant growth inhibitor containing a 1,4-dihydro-2,6-dimethyl-4-oxo-3-pyridinecarboxamide compound as an active ingredient, such as compound (I), Was not known.

This invention provides a group of novel compounds belonging to the 1,4-dihydro-2,6-dimethyl-4-oxo-3-pyridinecarboxamide compound and a plant growth inhibitor containing them.

(Object and Structure) According to the present invention, a compound represented by the following formula (I) and an addition salt thereof are provided.

In the formula, R is — (CH ₂ ) nR ₁ (n is an integer of 1 to 3; R ₁ is a hydrogen atom, a C _{3 to} C ₁₁ alkyl group or an aryl group); R ₂ , R ₃ , R ₄ ,
R ₅ and R ₆ are the same or different and each is a hydrogen atom, a halogen atom or a lower alkyl group, provided that at least three of the substituents of R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are groups other than hydrogen atom. R ₇ represents a hydrogen atom or a halogen atom, respectively.

In the present invention, the term (lower) used in the lower alkyl group means a group containing C _{1 to} C ₅ carbon atoms. Specific examples include lower alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl and isopentyl.

The aryl group includes a phenyl or naphthyl group. The halogen atom includes a chlorine, bromine or fluorine atom.

When the compound of formula (I) of the present invention shows basicity, it is an addition salt with an acid such as hydrochloric acid, sulfuric acid, phosphoric acid, methanesulfonic acid, paratoluenesulfonic acid, trifluoroacetic acid, or a carboxyl group in the molecule. May form an addition salt with an inorganic base. Such addition salts are also included in the scope of the present invention.

The compounds of formula (I) of this invention can be made by the following methods.

(Method A) (In the formula (II), R, R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are the same as the definition of the formula (I).)
I) and 2,2,6-trimethyl-4H-1,3-dioxin-4-
It is carried out by reacting one with an appropriate solvent (eg, toluene, xylene, etc.) under heating (eg, about 100 ° C. to 140 ° C.). Here, using 2-ethyl-2,6-dimethyl-4H-1,3-dioxin-4-one instead of 2,2,6-trimethyl-4H-1,3-dioxin-4-one Is also possible. In performing this method, 3-aminocrotonic acid anilide derivative (II)
Does not require the use of isolated material, the formula RNH ₂ (II
I) and (In the formulas (III) and (IV), R, R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are the same as the definition of the formula (I)), and the reaction mixture may be directly used. In fact,
It is more convenient to use this reaction mixture. This method is effective when R ₇ is hydrogen.

(Method B) (In the formulas (V) and (III), R, R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are represented by the formula (I).
The same is true for the 4-pyrone compound (V) corresponding to formula (I), namely 2,6-dimethyl-4-oxo-N-phenyl-4H-pyran-3-carboxamide and (III) Ammonia or amine represented by the formula or a salt thereof and a suitable solvent (eg, ethanol, water, etc.) at room temperature to 60
The reaction is performed at a temperature of about ° C. The amount of ammonia or amine used is equimolar or more to the 4-pyrone compound, and if necessary, a large excess amount is used. When the amine is obtained as a salt, it is necessary to provide the amine in a free form with a neutralizing amount or more of an organic or inorganic base.

(Method C) (R, R ₂ , R ₃ , R ₄ , R ₅ , R ₆ and R ₇ in formulas (VI) and (VII) are the same as the definition of formula (I)) This method corresponds to formula (I) Carboxylic acid ie 1,4
-Dihydro-2,6-dimethyl-4-oxo-3-pyridinecarboxylic acid derivative (VI) and aniline derivative (VII) are reacted in the presence of a dehydration condensation agent. When this method is actually carried out, for example, the method described in JP-A-52-57102, which uses a 1-substituted-2-halopyridinium salt and a tertiary amine as a dehydration condensation agent, can be advantageously used.

(Method C ') (R, R ₂ , R ₃ , R ₄ , R ₅ , R ₆ and R _{7 in} formulas (VIII) and (VII)
Is as defined in formula (I), and X is a halogen atom. ) This method comprises (VI) and an acid halide (VIII) easily obtained by a halogenating agent such as thionyl chloride.
And aniline derivative (VII) are reacted in the presence of a base.

(Method D) This method is a method applicable when R is a hydrogen atom in formula (I), and is 1,4-dihydro-2,6-dimethyl-4-oxo-N-phenyl-1- (Phenylmethyl) -3-pyridinecarboxamide was treated under hydrogenolysis reaction conditions and treated with 1,4-dihydro-2,6-dimethyl-
It is a method of converting into 4-oxo-N-phenyl-3-pyridinecarboxamide. Specific reaction conditions include:
Using hydrogen or formic acid as a hydrogen donor in a solvent of alcohols such as methanol or ethanol, palladium-
It is particularly preferred to use carbon or palladium black as the catalyst.

(Method E) 1,4-dihydro-2,6-dimethyl-4-, represented by formula (II) (wherein R, R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are the same as defined in formula (I)) An oxo-3-pyridinecarboxamide derivative,
It is possible to react with halogenating agents to produce compounds of formula (I). Particularly convenient is to use a halogenating agent such as N-chlorosuccinimide or N-bromosuccinimide, and use a radical in a solvent such as chlorinated hydrocarbon such as dichloromethane, chloroform, carbon tetrachloride, trichloroethylene or tetrachloroethane. The reaction is carried out in the presence or absence of an initiator. It is also possible to carry out the reaction by dissolving the compound represented by the formula (II) in the above-mentioned chlorinated carbon-hydrogen and blowing chlorine or bromine into the reaction mixture by a suitable method in the form of gas or dropping it in liquid form. it can.

The method of halogenating the compound of the formula (II) as described above is, however, recognized that a halogen atom is additionally introduced into the phenyl group on the amide nitrogen. This method
A method for synthesizing a compound in which R ₇ is a halogen atom.

When the plant growth inhibitor of the present invention is used in either soil treatment or foliage treatment, the application rate can be varied within a wide range, but usually 1 g to 200 g of the active ingredient per are.
It is preferably 5 g to 100 g, and the application concentration is 1% to 80% for wettable powders and water diluents for emulsions. The application amount and application concentration can be increased or decreased without depending on the above range depending on the type of formulation, application place, method, time, crop, degree of weed damage, and climatic conditions.

Hereinafter, the present invention will be described with reference to examples. The plant growth inhibitory effect of the compound of the present invention is shown in Reference Examples. In addition to the compounds shown in the examples, specific names of the compounds of interest included in the present invention include the following.

N- (4-Bromo-2,6-diethylphenyl) -1,4-dihydro-2,6-dimethyl-4-oxo-1-phenylmethyl-3-pyridinecarboxamide, N- (4-bromo-2, 6-Diethylphenyl) -5-chloro-1,4-dihydro-2,6-dimethyl-4-oxo-1
-Phenylmethyl-3-pyridinecarboxamide, N- (4-Bromo-2,6-diethylphenyl) -1-butyl-5-chloro-1,4-dihydro-2,6-dimethyl-4
-Oxo-3-pyridinecarboxamide, N- (4-bromo-2,6-diethylphenyl) -5-chloro-1,4-dihydro-2,6-dimethyl-4-oxo-1
-(2-Phenylethyl) -3-pyridinecarboxamide, N- (4-bromo-2,6-dimethylphenyl) -1-butyl-1,4-dihydro-2,6-dimethyl-4-oxo-3
-Pyridinecarboxamide, N- (4-Bromo-2,6-dimethylphenyl) -1,4-dihydro-2,6-dimethyl-4-oxo-1-phenylmethyl-3-pyridinecarboxamide, N- (4- Bromo-2,6-dimethylphenyl) -1,4-dihydro-2,6-dimethyl-4-oxo-1- (2-phenylethyl) -3-pyridinecarboxamide, 5-bromo-N- (4-bromo -2,6-Dimethylphenyl) -1-butyl-1,4-dihydro-2,6-dimethyl-4
-Oxo-3-pyridinecarboxamide, 5-bromo-N- (4-bromo-2,6-dimethylphenyl) -1,4-dihydro-2,6-dimethyl-4-oxo-1
-Phenylmethyl-3-pyridinecarboxamide, 5-bromo-N- (4-bromo-2,6-dimethylphenyl) -1,4-dihydro-2,6-dimethyl-4-oxo-1
-(2-Phenylethyl) -3-pyridinecarboxamide, N- (4-Bromo-2,6-dimethylphenyl) -5-chloro-1-butyl-1,4-dihydro-2,6-dimethyl-4
-Oxo-3-pyridinecarboxamide, N- (4-bromo-2,6-dimethylphenyl) -5-chloro-1,4-dihydro-2,6-dimethyl-4-oxo-1
-Phenylmethyl-3-pyridinecarboxamide, N- (4-bromo-2,6-dimethylphenyl) -5-chloro-1,4-dihydro-2,6-dimethyl-4-oxo-1
-(2-phenylethyl) -3-pyridinecarboxamide, 5-bromo-N- (4-bromo-2-ethyl-6-methylphenyl) -1-butyl-1,4-dihydro-2,6-dimethyl- 4-oxo-3-pyridinecarboxamide, 5-bromo-N- (4-bromo-2-ethyl-6-methylphenyl) -1,4-dihydro-2,6-dimethyl-4-oxo-1-phenylmethyl -3-Pyridinecarboxamide and 5-bromo-N- (4-bromo-2-ethyl-6-methylphenyl) -1,4-dihydro-2,6-dimethyl-4-oxo-1- (2-phenylethyl) ) -3-Pyridinecarboxamide.

Example 1 5-Bromo-N- (4-bromo-2,6-diethylphenyl) -1,4-dihydro-2,6-dimethyl-4-oxo-1
Synthesis of-(2-phenylethyl) -3-pyridinecarboxamide (according to Method E).

N- (4-Bromo-2,6-diethylphenyl) -1,4-dihydro-2,6-dimethyl-4-oxo-1- (2-phenylethyl) -3-pyridinecarboxamide 1 g (2.1 mmo
l), sodium carbonate 1.33g (12.5mmol), methylene chloride
A solution of bromine (340 mg, 2.1 mmol) in methylene chloride (6 ml) was added dropwise to the mixture (14 ml) over 30 minutes with stirring. The mixture was further stirred at room temperature for 3 hours, insoluble materials were removed by filtration, and the filtrate was concentrated. The obtained crystalline residue was recrystallized from ethanol to give 960 mg of the title compound (yield 82%). Melting point 190-19
1 ° C Example 2 1,4-Dihydro-2,6-dimethyl-N- (2,4,6-trimethylphenyl) -4-oxo-1-phenylmethyl-3
-Synthesis of pyridinecarboxamide (according to Method A).

2.93 g (13.4 mmol) of N- (2,4,6-trimethylphenyl) -3-oxo-butanamide, 1.43 g of benzylamine
A mixture of 2 drops of (13.3 mmol) acetic acid and 20 ml of toluene was stirred and kept at the reflux temperature for 1.5 hours, and water generated during that time was distilled out of the system together with about 12 ml of toluene. While maintaining the reaction mixture at reflux temperature, 2,2,6-trimethyl-4H-1,3-dioxin-4-one 4.75 g (33.4 mmol)
A toluene (12 ml) solution of was added dropwise over 30 minutes and then heated for another 1.5 hours. The reaction liquid was cooled to room temperature and then concentrated under reduced pressure, and the obtained yellow oily substance was separated by column chromatography to obtain 1.66 g of the title compound.

Tables 1 and 2 listed below summarize the physical properties and the like of the compounds according to the present invention.

The "performance evaluation" in Table 2 is as follows.

Talc (50 parts by weight), Bentonite (25 parts by weight) Sorpol-9047 (2 parts by Toho Chemical), Solpol-50
A carrier was prepared by mixing 39 (same as above, 3 parts by weight). 50 parts by weight of the test compound and 200 parts by weight of the carrier were mixed to prepare a 20% wettable powder. This wettable powder was dispersed in pure water to obtain a wettable powder dispersion having a predetermined concentration. Separately, a petri dish in which rice, Taenia serrata, and Japanese radish seeds were germinated was prepared, the above-mentioned wettable powder dispersion was added, and seedlings were grown for 7 days in a constant temperature cabinet at 25 ° C to observe the degree of growth. The results are displayed as follows: 1 = no effect, 2 = 25% growth inhibition, 3 = 50% growth inhibition, 4 = 75% growth inhibition, 5 = complete death.

Claims (10)

[Claims] 1. Formula (I): [In the formula, R is-(CH ₂ ) nR ₁ (n is an integer of 1 to 3; R ₁ is a hydrogen atom, a C _{3 to} C ₁₁ alkyl group or an aryl group); R ₂ , R ₃ and R
₄ , R ₅ and R ₆ are the same or different and each is a hydrogen atom, a halogen atom or a lower alkyl group, provided that at least three of the substituents of R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are hydrogen atoms or less. R ₇ is a hydrogen atom or a halogen atom] or a salt thereof. 2. The compound according to claim 1, wherein the lower alkyl group in R _{1 to} R ₆ of the formula (I) has 1 to 5 carbon atoms. 3. The compound according to claim 1, wherein the halogen atom in R _{1 to} R ₆ of the formula (I) is a chlorine atom. 4. The compound according to claim 1, wherein the aryl group in R _{1 to} R ₆ of the formula (I) is a phenyl group. 5. A compound of formula (I) Is a 4-bromo-2,6-diethylphenyl, 2,4,6-trimethylphenyl, 4-bromo-2,6-dimethylphenyl or 2-ethyl-4-bromo-6-methylphenyl group. The compound according to item 1 in the range. 6. A compound of formula (I) Is 2,4,6-trichlorophenyl, 2,4,6-tribromophenyl, 2,4,5-trimethylphenyl, 2,4,5-trichlorophenyl, 2,3,4-trichlorophenyl, 2, 3,5,6-tetrachlorophenyl, 2,3,5,6-tetrafluorophenyl, 2,3,4,5-tetrachlorophenyl, 2,3,4,5-tetrafluorophenyl, 2,3,4, The compound according to claim 1, which is a 5,6-pentafluorophenyl group. 7. The compound according to any one of claims 1 to 7, wherein-(CH ₂ ) nR _{1 of} formula (I) is a butyl or isobutyl, pentyl or isopentyl or hexyl group. 8. The method according to claim 1, wherein-(CH ₂ ) nR _{1 of} formula (I) is a phenylmethyl, 2-phenylethyl or 3-phenylpropyl group. Compound of. 9. 5-Bromo-N- (4-bromo-2,6-diethylphenyl) -1-butyl-1,4-dihydro-2,6-
Dimethyl-4-oxo-3-pyridinecarboxamide,
5-Bromo-N- (4-bromo-2,6-dimethylphenyl) -1,4-dihydro-2,6-dimethyl-4-oxo-1
-Phenylmethyl-3-pyridinecarboxamide, 5-
Bromo-N- (4-bromo-2,6-diethylphenyl)
-1,4-dihydro-2,6-dimethyl-4-oxo-1-
(2-phenylethyl) -3-pyridinecarboxamide, N- (4-bromo-2,6-diethylphenyl) -1
-Butyl-1,4-dihydro-2,6-dimethyl-4-oxo-3-pyridinecarboxamide, N- (4-bromo-2,
6-Diethylphenyl) -1,4-dihydro-2,6-dimethyl-4-oxo-1- (2-phenylethyl) -3-pyridinecarboxamide, 1-butyl-1,4-dihydro-
2,6-Dimethyl-N- (2,4,6-trimethylphenyl)-
4-oxo-3-pyridinecarboxamide, 1,4-dihydro-2,6-dimethyl-N- (2,4,6-trimethylphenyl) -4-oxo-1-phenylmethyl-3-pyridinecarboxamide, or 1 , 4-dihydro-2,6-dimethyl-
N- (2,4,6-trimethylphenyl) -4-oxo-1
The compound according to claim 1, which is-(2-phenylethyl) -3-pyridinecarboxamide or an addition salt thereof. 10. Formula (I) [Wherein R is — (CH ₂ ) nR ₁ (n is an integer of 1 to 3, R ₁ is a hydrogen atom; a C _{3 to} C ₁₁ alkyl group or an aryl group); R ₂ ,
R ₃ , R ₄ , R ₅ and R ₆ are the same or different and each is a hydrogen atom, a halogen atom or a lower alkyl group, provided that at least 3 of the substituents of R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are present. Is a group having a hydrogen atom or less; R ₇ is at least one compound or addition salt represented by a hydrogen atom or a halogen atom] as an active ingredient.