JPH08817B2 - 4-Thioxo-4H-pyran-3-carboxamide derivative and plant growth inhibitor - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel compound belonging to the 4-thioxo-4H-pyran-3-carboxamide compound.
The compound of this invention has a plant growth inhibitory action.

(Prior Art) Conventionally, compounds belonging to 4-thioxo-4H-bilane are known in the literature. Giogio Tra
verso) et al., by reaction of ethyl 2,6-dimethyl-4-oxa-4H-pyran-3-carboxylate with phosphorus pentasulfide, ethyl-2,6-dimethyl-4-oxo-4H-pyran-3-. You are getting a carboxylate. Ann. Sim. (Rohm) (ann.chim. (Rome) 45 695-705 This document describes the properties of the thiocarbonyl group of 4-thioxo-4H-pyran. Other compounds having a 4-thioxo-4H-pyran skeleton Are known, but 4-thioxo-4H-pyran-3- of the general formula (I)
No carboxamide compound is known.

(Structure of the Invention) The present invention provides a compound represented by the following general formula (I).

General formula [In the formula, R ₁ and R ₈ are the same or different and each represents a hydrogen atom,
C _{1 to} C ₁₁ alkyl group, lower alkenyl group, lower alkynyl group, cycloalkyl group, lower alkoxyalkyl group, optionally substituted phenyl group, aryl moiety is a halogen atom, lower alkoxy group 1 or 2
Aralkyl groups optionally substituted with 5 or 6-membered heterocyclic groups; 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 cyano group. , Nitro group,
Amino group, lower alkyl group, halogenated lower alkyl group, hydroxy group, lower alkoxy group, aryloxy group, carboxyl group or lower alkoxycarbonyl group; R
₇ represents a hydrogen atom, a halogen atom, a lower alkyl group, an optionally substituted phenyl group or an optionally substituted aralkyl group; R ₇ and R ₈ are taken together to form-(CH ₂ ) _m-
(M is 3 or 4) may be formed.

In the present invention, the term "lower" used for a lower alkyl group, a lower alkoxy group and the like means a group containing a C _{1 to} C ₅ carbon atom. Specifically, lower alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl and isopentyl; lower alkoxy groups such as methoxy, ethoxy, propoxy, isopropoxy and butoxy; methoxycarbonyl, ethoxycarbonyl, Lower alkoxycarbonyl groups such as propoxycarbonyl, butoxycarbonyl; methylthio, ethylthio, propylthio, isopropylthio, butylthio,
Lower alkylthio groups such as pentylthio are mentioned. Further, the lower alkenyl group and the lower alkynyl group include vinylallyl, isopropenyl, 2-butenyl, 1,
It includes 3-butadienyl, 2-pentenyl, 1,4-pentadienyl, 1-hexenyl, ethynyl, 2-propynyl and the like. Cycloalkyl groups include cyclopropyl, cyclopentyl, cyclohexyl and the like. Halogenated alkyl groups include trifluoromethyl, chloromethyl groups and the like. Lower alkoxyalkyl groups include methoxymethyl, ethoxymethyl, propoxymethyl, butoxymethyl groups and the like. Aralkyl groups include benzyl, 3-phenylpropyl, 4-phenylbutyl groups and the like. The aryloxy group includes a phenyloxy group and a naphthyloxy group. The 5- or 6-membered heterocyclic group includes a 5- or 6-membered heterocyclic group containing 1 to 3 heteroatoms selected from nitrogen atom and sulfur atom. Examples thereof include 5-membered ring groups such as furyl, tetrahydrofuryl, thienyl, thiazolyl, isothiazolyl, oxazolyl, isoxazolyl and pyrazolyl; and 6-membered ring groups such as pyridyl, pyrimidinyl, pyrazinyl and pyridazinyl. These groups may be substituted with alkyl groups such as methyl or ethyl, halogen atoms or phenyl groups. When substituted with a phenyl group, it may combine with two carbon atoms in the ring to form a fused ring. Examples of the case where a condensed ring is formed include benzothiazolyl, quinazolinyl, quinoxalinyl groups and the like.

The plant growth regulating action of the compound of the present invention is a property useful as a herbicide for paddy fields, uplands, fruit gardens, pastures, lawns, forests or non-agricultural lands. When the compound of the present invention is used as the above herbicide, it may be used as it is, but generally, it is mixed with a solid carrier, a liquid carrier, a surfactant, and other auxiliary agents for formulation to prepare a wettable powder and granules. , Emulsion, etc.

In these formulations, the compound of the present invention is a wettable powder, 10 to 50%
It is preferable to contain (all represent% by weight).

Solid carriers used in the formulation include kaolin, bentonite, clays, talc, diatomaceous earth, zealite, zeolite, pyrophyllite, synthetic silicon oxides, calcium carbonate, and other fine powders or granules. ,
Aromatic hydrocarbons such as xylene and methylnaphthalene, alcohols such as ethanol, isopropanol, ethylene glycol and methyl cellosolve, ketones such as acetone, isophorone and cyclohexynone, vegetable oils such as soybean oil and cottonseed oil, dimethylformamide and dimethyl sulfoxide. , Acetonitrile, water, etc.

Surfactants used for dispersion, emulsification, etc.,
Polyoxyethylene alkyl ether, polyoxyethylene alkylaryl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, nonionic surfactant such as polyoxyethylene polyoxypropylene block polymer, alkyl sulfate ester salt , An alkyl sulfonate, an alkyl aryl sulfonate, and an anionic surfactant such as polyoxyethylene alkyl sulfate.

Pharmaceutical auxiliary agents include lignin sulfonate, alginate, polyacrylates, polyvinyl alcohol, plant gums, camboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC) and the like.

Further, the compound of the present invention can be used in combination with other insecticides, acaricides, nematicides, fungicides, herbicides, plant growth regulators, fertilizers or soil conditioners, if necessary.

The compound represented by formula (I) of the present invention can be synthesized by the following method.

(R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , represented by the general formula (II),
R ₇ and R ₈ are the same as the definition of the general formula (I). The compound represented by the general formula (II) is treated with phosphorus pentasulfide, 2,4-bis [4-methoxyphenyl] -1, It can be obtained by reacting with a sulfiding agent such as 3-dithia-2,4-diphosphetane-2,4-disulfide.

 Next, the present invention will be described with reference to examples.

In addition to the compounds shown in Examples, specific names of the compounds of interest included in the present invention include the following.

N- (4-bromo-2,6-diethylphenyl) -2-
Butyl-5,6-dimethyl-4-thioxo-4H-pyran-
3-carboxamide, N- (4-bromo-2,6-diethylphenyl) -5,6-dimethyl-2-propyl-4-thioxo-4H-pyran-3-carboxamide, 5-ethyl-N- (4- Bromo-2,6-diethylphenyl) -2-butyl-6-methyl-4-thioxa-4H-pyran-3-carboxamide, 6-ethyl-N- (4-bromo-2,6-diethylphenyl) -2 -Butyl-5-methyl-4-thioxo-4H-3
-Carboxamide, 5-ethyl-N- (4-bromo-2,6-diethylphenyl) -6-methyl-2-propyl-4-thioxo-4H-
Pyran-3-carboxamide, 6-ethyl-N- (4-bromo-2,6-diethylphenyl) -5-methyl-2-propyl-4-thioxo-4H-
Pyran-3-carboxamide, N- (2,6-diethyl-4-methoxyphenyl) -2-
Butyl-5,6-dimethyl-4-thioxo-4H-pyran-
3-carboxamide, N- (2,6-diethyl-4-methoxyphenyl) -5,6-
Dimethyl-4-thioxo-2-propyl-4H-pyran-
3-carboxamide, N- (4-bromo-2,6-diethylphenyl) -6-methyl-2,5-dipropyl-4-thioxo-4H-pyran-
3-carboxamide, N- (2,4,6-triethylphenyl) -5,6-dimethyl-
4-Thioxo-2-propyl-4H-pyran-3-pyridinecarboxamide.

(Example) Example 1 2-butyl-N- (2,6-diethylphenyl) -6-
Synthesis of methyl-4-thioxo-4H-pyran-3-carboxamide.

2-Butyl-N- (2,6-diethylphenyl) -6-methyl-4-oxo-4H-pyran-3-carboxamide 0.
68g (2mmol), Lawesson reagent 480mg
A mixture of (1.2 mmol) and toluene (10 ml) was refluxed for 3 hours. Toluene was distilled off under reduced pressure, the obtained residue was purified by column chromatography, and the obtained residue was recrystallized from a mixed solution of isopropyl ether and ethyl acetate to obtain 0.45 g of the title compound.

Example 2 2-Trifluoromethylphenyl-6-methyl-N-
Synthesis of phenyl-4-thioxo-4H-pyran-3-carboxamide.

2-trifluoromethylphenyl-6-methyl-4-
0.15 g of the title compound was obtained in the same manner as in Example 1 using 0.75 g (2 mmol) of oxo-N-phenyl-4H-pyran-3-carboxamide.

Example 3 N- (2,6-diethylphenyl) -5,6-dimethyl-2
Synthesis of -n-propyl-4-thioxo-4H-pyran-3-carboxamide.

N- (2,6-diethylphenyl) -5,6-dimethyl-4-
0.19 g of the title compound was obtained in the same manner as in Example 1 using 0.84 g (2 mmol) of oxo-2-propyl-4H-pyran-3-carboxamide.

Next, 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, Solpol-
9047 (manufactured by Toho Kagaku Co., Ltd.) and 3 parts by weight of Solpol-5039 (same as above) were mixed to prepare a carrier. 50 parts by weight of the test compound and 200 parts by weight of the carrier are mixed, and 2
Made 0% 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 cinerea, and Japanese radish seeds were germinated was prepared, the above-mentioned wettable powder dispersant was added, and seedlings were grown for 7 days in a constant temperature oven at 25 ° C to observe the degree of growth.

Results are displayed as follows: 1 = no effect, 2 = 25% growth suppression, 3
= 50% growth suppression, 4 = 75% growth suppression, 5 = complete death.

 ─────────────────────────────────────────────────── ─── Continued Front Page (56) References JP-A-61-158977 (JP, A)

Claims (2)

[Claims] 1. A general formula [In the formula, R ₁ and R ₈ are the same or different and each represents a hydrogen atom, C ₁ to
C ₁₁ alkyl group, lower alkenyl group, lower alkynyl group, cycloalkyl group, lower alkoxyalkyl group, optionally substituted phenyl group, aryl moiety substituted with one or two halogen atoms or lower alkoxy groups An optionally substituted aralkyl group, a 5- or 6-membered heterocyclic 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, a cyano group, a nitro group, an amino group, a lower alkyl group, a halogenated lower alkyl group, a hydroxy group, a lower alkoxy group, Aryloxy group, carboxyl group or lower alkoxycarbonyl group; R ₇ is a hydrogen atom,
A halogen atom, a lower alkyl group, an optionally substituted phenyl group or an optionally substituted aralkyl group; R ₇ and R ₈ together are-(CH ₂ ) _m- (m is 3 or 4 ) May be formed. ] 4-thioxo-4H-pyran-3-carboxamide derivative represented by these. 2. General formula [In the formula, R ₁ and R ₈ are the same or different and each represents a hydrogen atom, C ₁ to
C ₁₁ alkyl group, lower alkenyl group, lower alkynyl group, cycloalkyl group, lower alkoxyalkyl group, optionally substituted phenyl group, aryl moiety substituted with one or two halogen atoms or lower alkoxy groups An optionally substituted aralkyl group, a 5- or 6-membered heterocyclic 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, a cyano group, a nitro group, an amino group, a lower alkyl group, a halogenated lower alkyl group, a hydroxy group, a lower alkoxy group, Aryloxy group, carboxyl group or lower alkoxycarbonyl group; R ₇ is a hydrogen atom,
A halogen atom, a lower alkyl group, an optionally substituted phenyl group or an optionally substituted aralkyl group; R ₇ and R ₈ together are-(CH ₂ ) _m- (m is 3 or 4 ) May be formed. ] The plant growth inhibitor containing the 4-thioxo-4H-pyran-3-carboxamide derivative represented by these.