Optically active uracil compounds

Details Optically active uracil compounds Optically active uracil compounds

1999-12-23

2002-05-21

Ford, John M. (Department: 1614)

Plant protecting and regulating compositions

Plant growth regulating compositions

Organic active compound containing

C544S314000

Reexamination Certificate

active

06391826

ABSTRACT:

FIELD OF THE INVENTION
The instant invention relates to optically active uracil compounds and uses thereof.
BACKGROUND ARTS
U.S. Pat. No. 4,859,229 discloses that certain types of uracil compounds have herbicidal activity. However, there is no description concerning whether the herbicidal activities between the optical isomers are the same or different, or which optical isomer is more effective as a herbicidal active ingredient.
Generally speaking, in pesticides field, it is known that some optically active isomers have almost the same activity as their racemic compounds and the other optically active isomers have at most twice activity than their racemic compounds. It seems to be dependent on a structure near the asymmetric carbon in the compound whether the pesticidal activity between the optical isomers is the same or different. However, it is very difficult to estimate a pesticidal activity of an optical isomer without experimentation. When one optical isomer is almost inactive, the other optical isomer is theoretically considered to be effective twice against its racemate, because the racemate contains a half amount of the active optical isomer.
DISCLOSURE OF THE INVENTION
The present invention provides optically active uracil compounds having excellent herbicidal activity. Said uracil compounds are of the formula (I):
wherein, R
1
is C1-C8 alkyl or C3-C8 alkenyl, and * represents an asymmetric carbon atom whose configuration is R, and have excellent herbicidal activity.
DETAILED DESCRIPTION OF THE INVENTION
The present uracil compounds may be essentially pure R isomer in the 2
nd
position of the propionate, namely essentially free from S isomer, or R-rich isomers of the absolute configuration in the 2
nd
position of the propionate, shown in the above formula [hereinafter referred to as the present compound(s)]. In the present invention, essentially pure R isomer means one containing 95% or more R isomer, and R-rich isomer generally means one containing 80% or more R isomer based on the RS mixture.
In the present invention, examples of the C1-C8 alkyl represented by R
1
include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, amyl, isoamyl, sec-amyl, tert-amyl and hexyl, and examples of the C3-C
8 alkenyl represented by R
1
include allyl, 1-methyl-2-propenyl, 3-butenyl, 2-butenyl, 3-methyl-2-butenyl and 2-methyl-3-butenyl. Among the present compounds, the compounds wherein R
1
is C1-C6 alkyl or C3-C6 alkenyl are preferable.
The present compounds can be produced by methods, for example, shown in the following.
(Production Method 1)
A method of production by reacting a hydroxy compound of the formula (II):
with an S-lactate of the formula (III):
wherein R
1
represents the same as defined above.
Said reaction is usually performed in the presence of a triarylphosphine or trialkylphosphine such as triphenylphosphine, triethylphosphine, tributylphosphine and the like, in combination with a di(lower alkyl) azodicarboxylate such as diethyl azodicarboxylate, diisopropyl azodicarboxylate, and the like. Said reaction is usually performed within a solvent, and the range of the reaction temperature is usually −20 to 150° C., preferably 0 to 100° C., and the range of the reaction time is instantaneous to 48 hours. The amount of the S-lactate of the formula (III) used in the reaction is generally 1 to 3 moles, preferably 1 to 1.2 moles, based on 1 mole of the hydroxy compound of the formula (II). The amount of the triarylphosphine or trialkylphosphine is generally 1 to 3 moles, preferably 1 to 1.2 moles, and the amount of the di(lower alkyl) azodicarboxylate is generally 1 to 3 moles, preferably 1 to 1.2 moles, based on 1 mole of the hydroxy compound of the formula (II). Examples of the solvent utilized for the reaction include aliphatic hydrocarbons such as hexane, heptane, ligroin, cyclohexane and petroleum ether; aromatic hydrocarbons such as benzene, toluene and xylene; halogenated aromatic hydrocarbons such as chlorobenzene, dichlorobenzene and benzotrifluoride; ethers such as diethyl ether, diisopropyl ether, dioxane, tetrahydrofuran and ethylene glycol dimethyl ether; and the like, and mixtures thereof. After completing the reaction, for example, by the methods shown below, the objective present compounds can be isolated.
1) The reaction solution is poured into water, that is extracted with an organic solvent, said organic layer is dried and concentrated, and the residue is subjected to chromatography.
2) The reaction solution is concentrated as it is, and the residue is subjected to chromatography.
In addition, it is possible to purify the present compounds by operations such as recrystalization.
The hydroxy compound of the formula (II) can be prepared by the method described in U.S. Pat. No. 4,859,229.
(Production Method 2)
A method of production by reacting a hydroxy compound of the formula (II) with an S-2-chloropropionate of the formula (IV):
wherein R
1
represents the same as defined above.
Said reaction is usually performed in the presence of a base within a solvent, and the range of the reaction temperature is usually −20 to 100° C., preferably 0 to 40° C., and the range of the reaction time is instantaneous to 240 hours. The amount of the S-2-chloropropionate of the formula (IV) used in the reaction is generally 1 to 2 moles, preferably 1 to 1.2 moles, based on 1 mole of the hydroxy compound of the formula (II). The amount of the base is generally 1 to 3 moles, preferably 1 to 1.2 moles, based on 1 mole of the hydroxy compound of the formula (II). Examples of the base utilized for the reaction include inorganic bases such as lithium carbonate, sodium carbonate, potassium carbonate, sodium hydride and potassium hydride. Examples of the solvent utilized for the reaction include aliphatic hydrocarbons such as hexane, heptane, ligroin, cyclohexane and petroleum ether; aromatic hydrocarbons such as benzene, toluene and xylene; halogenated aromatic hydrocarbons such as chlorobenzene, dichlorobenzene and benzotrifluoride; ethers such as diethyl ether, diisopropyl ether, dioxane, tetrahydrofuran and ethylene glycol dimethyl ether; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, isophorone and cyclohexanone; esters such as ethyl formate, ethyl acetate, butyl acetate and diethyl carbonate; nitriles such as acetonitrile, propionitrile and butyronitrile; acid amides such as formamide, N,N-dimethylformamide and acetamide; sulfur compounds such as dimethyl sulfoxide and sulfolane; and the like, and mixtures thereof. After completing the reaction, for example, by the methods shown below, the objective present compounds can be isolated.
1) The reaction solution is poured into water, that is extracted with an organic solvent, said organic layer is dried and concentrated, and the residue is subjected to chromatography.
2) The reaction solution is concentrated as it is, and the residue is subjected to chromatography.
(Production Method 3)
A method of producing from a carboxylic acid compound of the formula (V):
and an alcohol compound of the formula (VI):
R
1
OH
wherein R
1
represents the same as defined above.
(Production Method 3-1)
A method of producing by reacting a carboxylic acid compound of the formula (V) with an alcohol compound of the formula (VI) directly.
Said reaction is usually performed in the presence of an acid, without or within a solvent, and the range of the reaction temperature is usually from 20 to 150° C., preferably 50 to 100° C., and the range of the reaction time is usually from instantaneous to 24 hours. The amount of the alcohol compound of the formula (VI) used in the reaction is generally 1 mole to a large excess and the amount of the acid is generally a catalytic amount to 1 mole based on 1 mole of the carboxylic acid compound of the formula (V). Examples of the acid utilized for the reaction include inorganic acid such as sulfuric acid; sulfonic acid such as methanesulfonic acid, trifluoromethanesulfonic acid, p-toluenesulfonic acid, benzenesulfonic acid; ion-exchange resin t

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