JPS63198669A - Dihydropyrimidine derivative and plant-growth inhibitor - Google Patents

Abstract

NEW MATERIAL:The dihydropyrimidine derivative of formula I [R<1> and R<2> are alkyl, halogenated lower alkyl or (substituted)phenyl; R<3> is lower alkyl; R<4>-R<8> are H, halogen or lower alkyl]. EXAMPLE:4-Butyl-N-(2,6-diethylphenyl)-dihydro-2,6-dimethyl-5-pyrimidin ecarboxy amide. USE:A plant growth inhibitor. PREPARATION:The compound of formula I can be produced by reacting an alpha,beta-unsaturated carbonyl compound of formula II with an amidine compound of formula III in an inert solvent such as ethanol and heating the resultant tetrahydropyrimidine derivative of formula IV together with an acid such as p-toluenesulfonic acid to effect the dehydration of the derivative.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a novel compound belonging to 2,4,6-doli-substituted pyrimidine-5-carboxylic acid anilide and a plant growth inhibitor.

(Prior art) Conventionally, compounds belonging to pyrimidine-5-carboxylic acid anilide are J, Chem, Tsuku, (J, Chem, So
c, ) 1965, 6695 and JP-A-61-43
The one described in No. 173 is known. However, these compounds differ from the compounds of the present invention in that a nitrogen atom is bonded to the 2-position of the pyrimidine ring. rank, 4
A pyrimidine in which all of the substituents at position and 6 have carbon-carbon bonds with the carbon forming the pyrimidine ring.
5-carboxylic acid anilide derivatives were completely unknown heretofore.

(Object and Structure) The present invention provides a dihydropyrimidine derivative represented by the following formula (I>).

R group, halogenated lower alkyl group, or optionally substituted phenyl group: R3 is a lower alkyl group; R4, R5,
R6, R7, and R8 are the same or different and are a hydrogen atom, a halogen atom, or a lower alkyl group).

The present invention also provides a plant growth inhibitor containing at least one of the above compounds as an active ingredient. In the compound of formula (I) above, the alkyl group has 1 to 1 carbon atoms.
Two straight or branched hydrocarbon groups, including methyl, ethyl, propyl, isopropyl, butyl, isobutyl, secondary butyl, pentyl, isopentyl, 1-methylbutyl, 1-ethylpropyl, hexyl, and octyl groups. etc. are included.

The halogenated lower alkyl group includes trifluoromethyl,
difluoromethyl, fluoromethyl, chloromethyl, 2
-Chloroethyl, 3-chloropropyl, 2-bromoethyl, 4-chlorobutyl, and the like.

The phenyl group in R1 and R2 includes an unsubstituted phenyl group, a halogen atom, a cyano group, a nitro group, an amino group, a lower alkyl group, a halogenated lower alkyl group,
Included are hydroxy groups, phenyl groups substituted with 1 to 3 lower alkoxy groups, and the like.

Examples of lower alkyl groups include alkyl groups having 1 to 6 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tertiary butyl, pentyl,
Examples include isopentyl.

Halogen atoms include chlorine, bromine, fluorine and iodine.

Lower alkoxy groups include methoxy, ethoxy, propoxy and the like.

Further, the compound of formula (I>) of the present invention can form an addition salt with an acid such as hydrochloric acid, sulfuric acid, phosphoric acid, methanesulfonic acid, p-toluenesulfonic acid, or trifluoroacetic acid. Within the scope of the invention. The compound of formula (I>) of this invention can be prepared by the method shown below.

First, a tetrahydropyrimidine derivative (1v) is obtained by reacting an α,β-unsaturated silvonyl compound represented by formula (II) with an amidine compound (I[I) in an inert solvent such as ethanol or methanol. . When using a salt such as a hydrochloride of an amidine compound, it is preferable to form it into a free form with an alkali metal alkoxide in advance.

(Blank below, continued on next page) (rV) (I') (R1, R2, R3, R4, R5, R6, R in each of the above formulas)
7. R8 represents the same meaning as defined in formula (I>) The tetrahydropyrimidine derivative (IV) thus obtained is heated with an acid such as P-toluenesulfonic acid or benzenesulfonic acid, or The formula (I> or
A dihydropyrimidine derivative represented by ') is obtained.

Naotake (I) and (I') are tautomers.

This dihydropyrimidine derivative (I> or (■') is combined with manganese dioxide, sulfur, 2,3-dichloro-5,6
- Compound (V) by reacting with an oxidizing agent such as dicyano-1,4-benzoquinone, potassium permanganate, nitrous acid, chromic acid, iodine, palladium-carbon, etc.
can be obtained.

The compound of formula (V) can also be prepared by mixing the compound of formula (V) with hydrogen peroxide, a hydroperoxide such as t-butyl hydroperoxide, or peracetic acid, perbenzoic acid, or m-chloroperoxide in a suitable solvent. 1-oxide or 3-oxide compounds are obtained by treatment with an oxidizing agent such as an organic peracid such as benzoic acid.

In the plant growth inhibitor of the present invention, the dihydropyrimidine derivative represented by the formula (I>) may be used as it is as an active ingredient, but it is generally combined with a solid carrier, liquid carrier, surfactant, or other formulation auxiliary agent. They are mixed and formulated into wettable powders, granules, emulsions, etc.These preparations contain the compound of the present invention in an amount of 10 to 80% for wettable powders, 2 to 20% for granules, and 10% for emulsions.
It is preferable to contain 50% to 50% (all percentages are by weight). Solid carriers used in the formulation include kaolin,
Bentonite, clays, talc, diatomaceous earth, seekrite, zeolite, pyrophyllite, synthetic silicon oxide,
There are fine powders or granules such as calcium carbonate, and liquid carriers include aromatic carbon hydrogens such as xylene and methylnaphthalene, alcohols such as ethanol, isopropanol, ethylene glycol, and methyl cellosolve, acetone, Examples include ketones such as irophorone and cyclohexanone, vegetable oils such as soybean oil and cottonseed oil, dimethylformamide, dimethyl sulfoxide, acetonitrile, and water. Surfactants used for dispersion, emulsification, etc. include polyoxyethylene alkyl ether, polyoxyethylene alkylaryl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene polyoxy Nonionic surfactants such as brobylene block polymers, alkyl sulfate salts, alkyl sulfonate salts,
There are anionic surfactants such as alkylaryl sulfonates and polyoxyethylene alkyl sulfate salts.

Pharmaceutical auxiliaries include lignin sulfonates, alginates, polyacrylates, polyvinyl alcohol, vegetable gums, carboxymethyl cellulose (CMC), hydroxyethyl cellulose (NEC), and the like.

The wettable powders and emulsions prepared in the manner described above are usually diluted with water, and the granules can be used as they are by spraying on the soil or on foliage and on the soil.

The plant growth inhibitor of the present invention may be used in combination with other plant growth inhibitors, insecticides, nematicides, fungicides, fertilizers, or soil conditioners, if necessary.

Hereinafter, the present invention will be explained by examples. Table 1 shows the characteristic values of the compounds mentioned in the examples, and Table 2 shows the growth-inhibiting effect of the plant growth inhibitor of the present invention on plants.

The method for measuring the plant growth inhibitory effect is as follows.

Talc (50 parts by weight), bentonite (25 parts by weight),
A carrier was prepared by mixing Sorbo-Rue 9047 (manufactured by Toho Chemical Co., Ltd., 2 parts by weight) and Sorbo-Rue 5039 (manufactured by Toho Chemical Co., Ltd., 3 parts by weight). A 20% wettable powder was prepared by mixing 50 parts by weight of the test compound and 200 parts by weight of the carrier.

This hydrating powder was dispersed in pure water to obtain a hydrating powder dispersion having a predetermined concentration. Separately, petri dishes in which seeds of rice, Japanese millet, and Japanese radish were germinated were prepared, the above-mentioned hydrating agent dispersion was added, and the seedlings were grown for 7 days in a constant temperature warehouse with lighting at 25° C., and the degree of growth was observed. How to display the results: 1 - no effect, 2 = 25% growth inhibition, 3 = 50% growth inhibition, 4 = 75% growth inhibition, 5
= complete withering.

Example 1 2.33 g ('10 mmol) of N-(2,6-dinitylphenyl)-3-oxobutyric acid amide, 1 pentanal
, 12 g (13 mmol), 2 drops of piperidine, and 10 Wdl of methylene chloride was stirred for 5 hours under water cooling, and then allowed to stand at 4 to 5°C for 2 days. After the produced water was removed with anhydrous sodium sulfate, the solvent was removed by drying using a vacuum bottom-tally evaporator to obtain a residue.

Separately, 0.95 g (10 mmol) of acetamidine hydrochloride was dissolved in 50 me of absolute ethanol, and 0.68 g (10 I!1 mol) of room temperature tenium ethylate was added and stirred for 1 hour to prepare an acetamidine solution.

The residue obtained earlier was mixed with 401 d of ethanol and 10 d of water.
Dissolve in a mixture of and add this to the acetamidine solution,
Stirred at room temperature for 1 hour. Ethanol was distilled off under reduced pressure, saturated brine was added, and extraction with methylene chloride was performed. After removing the solvent, crystallization from ethyl acetate yields 4-butyl-N-(2,
1.04 g of compound N0.1> was obtained.

Melting point: 261-270℃ IR (K[Sr disk): 1632, 1665ra
-'NMR(CDCl2>δ value 0.60-2.10(
m, 9H), 1.18 (t, 6H), 1.48 (
s, 3H), 1.92 (s, 3H), 2.10-2
．． 90 (m, 1H), 2.63 (q, 4l-t)
, 3.40-4.20 (m, 1H), 6.97-7
゜30 (m, 3H> 4-butyl-N-(2,6-dinitylphenyl)-1,
4,5,6-tetrahydro-6-hydroxy-2,6-
Cymethyl-5-pyrimidinecarboxamide 900■, P
- A mixture of 700 Wj of toluenesulfonic acid monohydrate and 10 WJ of benzene was heated under reflux for 1°5 hours. Benzene was distilled off from the reaction solution under reduced pressure, an aqueous potassium carbonate solution was added, and the mixture was extracted with methylene chloride. After removing the solvent from the organic layer, crystallization from ethyl acetate yields 4-butyl-N-
(2,6-dinitylphenyl)-dihydro-2゜6-dimethyl-5-pyrimidinecarboxamide (compound No.
6> was obtained in 343/I7y.

Melting point: 149-155.5°C IR (KBr disk): 1620.1675 cm-1 NMR (CDCl2>δ value: 0.60-2.10 (m,
9H) , 1.17 (t, 6H> , 1.91(s,
3H) , 2.17 (s, 3H) , 2.57 (Q,
4l-1), 2.80-4.00 (br,'IN>
4.44 (t, 1H), 6.82 (s, 1f-(>
, 6.95-7.30 (m, 3H> Examples 2 to 4 The following compounds were obtained from the corresponding β-ketoamide derivatives and aldehydes in the same manner as in Example 1.

N-(4-bromo-2,6-dinitylphenyl)-4-
Butyl-dihydro-2,6-dimethyl-5=pyrimidinecarboxamide (Example 2, Compound No., 7>N
-(2,6-dinitylphenyl)-2,4-dimethyl-
Dihydro-6-benzene-5-pyrimidinecarboxamide (Example 3, Compound No. 8> N-(2,6-dinitylphenyl)-2,4-dimethyl-dihydro-6-propyl-5-pyrimidinecarboxamide (Example 4, Compound No. 9>Example 5 N-(2,6-dinitylphenyl)-3-okynebutyric acid amide 9.33 g (40 mmol), benzaldehyde 4.20 g (40 mmol), piperidine 0.2 m,
Heating a mixture of 0.5 d of acetic acid and 40 m of benzene,
The mixture was refluxed for 2 hours while removing by-product water. After the reaction mixture was washed successively with 1N hydrochloric acid, water, and saturated aqueous sodium bicarbonate, the solvent was removed under reduced pressure to obtain a residue.

Separately, 3.78 g of acetamidine hydrochloride was dissolved in 200 d of absolute ethanol, and 2.0 g of sodium ethylate was dissolved at room temperature.
72 g was added and stirred for 1 hour to prepare an acetamidine solution.

The residue obtained earlier was dissolved in 400 d of ethanol, added to the acetamidine solution, and stirred at room temperature for 1 hour.

Ethanol was distilled off under reduced pressure, saturated brine was added, and extraction with methylene chloride was performed. After removing the solvent, crystallization from a mixture of ethyl acetate and hexane yields N-(2,6-dinitylphenyl)-1°4.5.6-tetrahydro-4-hydroxy-2°4-dimethyl-6-phenyl. 6.659 of -5-pyrimidinecarboxamide (compound No. 5>) was obtained.

IR (KBr disk): 1622.16701J-1 NMR (CDCl2-DMSO-d6) δ value: 0.92
(t, 6H), 1.68 (s, 3H>, 1, 80
-2.40 (m, 5H), 2.04 (s.

3H), 3.30-4.00 (m, 1f-1>,
6°80-7.60 (m, 8H) The obtained N-(2,6-dinitylphenyl)-1,4,
The title compound was obtained from 5,6-tetrahydro-4-hydroxy-2,4-dimethyl-6-phenyl-5-pyrimidinecarboxamide by performing a dehydration reaction in the same manner as in Example 1.

Claims (4)

[Claims] (1) Formula (I): ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, R^1 and R^2 are the same or different and are an alkyl group, a halogenated lower alkyl group, or a substituted optional phenyl group; R^3 is lower alkyl group; R^4, R^
5. R^6, R^7, and R^8 are the same or different and are a hydrogen atom, a halogen atom, or a lower alkyl group); a dihydropyrimidine derivative; (2) Claim No. (1) in which R^3 is a methyl group
Compounds described in Section. (3) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ in formula (I) is 2,
The compound according to claims (1) and (2), which is a 6-diethylphenyl group or a 4-bromo-2,6-diethylphenyl group (4) Formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, R^1 and R^2 are the same or different and are an alkyl group, a halogenated lower alkyl group, or a substituted Good phenyl group; R^3 is lower alkyl group; R^4, R^
5. R^6, R^7, and R^8 are the same or different and contain at least one dihydropyrimidine derivative represented by a hydrogen atom, a halogen atom, or a lower alkyl group as an active ingredient. Plant growth inhibitor.