Organic compounds -- part of the class 532-570 series – Organic compounds – Heterocyclic carbon compounds containing a hetero ring...
Reexamination Certificate
2000-09-18
2002-12-10
Morris, Patricia L. (Department: 1625)
Organic compounds -- part of the class 532-570 series
Organic compounds
Heterocyclic carbon compounds containing a hetero ring...
C548S263400
Reexamination Certificate
active
06492527
ABSTRACT:
The present invention relates generally to the field of process chemistry as used in the preparation of commercially valuable chemical products. In particular, it pertains to processes related to 1-aryltriazolinone ring formation and to novel intermediates useful in these processes.
The compound 4,5-dihydro-3-methyl-1-phenyl-1,2,4-triazol-5(1H)-one, among others, is a particularly useful 1-aryltriazolinone critical in the manufacture of commercially important herbicides. For example, U.S. Pat. Nos. 4,818,275 and 5,125,958 fully describe conversions of 1-aryltriazolinone intermediates to known herbicides.
Some known methods for the preparation of 1-aryltriazolinones require formation of a 1-aryltriazolidinone ring followed by conversion of the 1-aryltriazol-idinone ring to the desired 1-aryltriazolinone. This requirement is disadvantageous because it adds an additional step to the process of preparing 1-aryltriazolinones. Other known methods provide less than optimum yields of 1-aryltriazolinone because of by-product formation. Given the commercial value of 1-aryltriazolinones, improved processes for their preparation are therefore needed.
SUMMARY OF THE INVENTION
It has now been found that commercially useful 1-aryltriazolinones of formula I
can be prepared in excellent yield and purity by (i) carbonylating an amidrazone of formula (A) with at least one carbonylating agent, or by (ii) condensing a hydrazonoyl derivative of formula (A) with at least one ring-forming agent, wherein formula (A) is
where W, X, Y, Z, and R
1
are fully described below. Preferred are those where W is halogen or —NHR where R is hydrogen or haloalkyl; X and Y are independently selected from hydrogen, chloro, or fluoro; Z is hydrogen, bromo, iodo, nitro, amino, or methylsulfonylamino; and R
1
is methyl. Additionally, certain compounds of formula (A) used to prepare 1-aryltriazolinones of formula I are also novel and are included among the preferred embodiments of the present invention. These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description and appended claims.
Definitions
The modifier “about” is used herein to indicate that certain preferred operating ranges, such as ranges for molar ratios for reactants, material amounts, and temperature, are not fixedly determined. The meaning will often be apparent to one of ordinary skill. For example, a recitation of a temperature range of about 120° C. to about 135° C. in reference to, for example, an organic chemical reaction would be interpreted to include other like temperatures that can be expected to favor a useful reaction rate for the reaction, such as 105° C. or 150° C. Where guidance from the experience of those of ordinary skill is lacking, guidance from the context is lacking, and where a more specific rule is not recited below, the “about” range shall be not more than 10% of the absolute value of an end point or 10% of the range recited, whichever is less.
As used in this specification and unless otherwise indicated the substituent terms “alkyl”, “alkoxy”, and “haloalkyl”, used alone or as part of a larger moiety, includes straight or branched chains of at least one or two carbon atoms, as appropriate to the substituent, and preferably up to 12 carbon atoms, more preferably up to ten carbon atoms, most preferably up to seven carbon atoms. The term “aryl” refers to phenyl or naphthyl optionally substituted with one or more halogen, alkyl, alkoxy, or haloalkyl. “Halogen” or “halo” refers to fluorine, bromine, iodine, or chlorine. The term “ambient temperature” refers to a temperature in the range of about 20° C. to about 30° C. Certain solvents, catalysts, and the like are known by their acronyms. These include the acronyms “DMAC” meaning N,N-dimethylacetamide, “DMF” meaning N,N-dimethylformamide, “THF” meaning tetrahydrofuran, “DMAP” meaning 4-dimethylaminopyridine, “DBN” meaning 1,5-diazabicyclo[4.3.0]non-5-ene, and “DBU” meaning 1,8-diazabicyclo[5.4.0]undec-7-ene. The term “glymes” refers to a class of solvents comprised of monoglyme, diglyme, triglyme, tetraglyme, and polyglyme. The term “GC” refers to gas chromatography or gas chromatographic methods of analyses.
The term “amidrazone” or “amidrazone of formula (A)” is synonymous with and refers to a 2-(optionally-substituted phenyl)hydrazidethaneimidic acid, for example, but not limited to 2-(2,4-dichlorophenyl)hydrazidethaneimidic acid. The term “hydrazonoyl derivative” or “hydrazonoyl derivative of formula (A)” is synonymous with and refers to a N-(optionally-substituted phenyl)ethanehydrazonoyl derivative, for example, but not limited to N-(2,4-dichlorophenyl)ethanehydrazonoyl chloride. The term “compound or compounds of formula (A)” refers to both amidrazone and hydrazonoyl derivatives. The term “compound or compounds of formula I” is synonymous with and refers to 1-aryltriazolinone(s), for example, but not limited to 4,5-dihydro-1-(2,4-dichlorophenyl)-3-methyl-1,2,4-triazol-5(1H)-one.
DETAILED DESCRIPTION OF THE INVENTION
One embodiment of the present invention relates to a process for preparing a compound of formula I:
wherein an amidrazone of formula (A) is carbonylated with at least one carbonylating agent, where formula (A) is:
and wherein X and Y are independently selected from hydrogen, halogen, nitro, and amino; Z is selected from hydrogen, halogen, alkyl, alkoxy, nitro, amino, or alkylsulfonylamino; W is —NHR where R is hydrogen, alkyl, or haloalkyl; and R
1
is hydrogen, alkyl, haloalkyl, alkoxy, acetyl, or aryl.
Preferred species of amidrazone (A) with which to conduct the carbonylation reaction of the present invention are selected from those wherein X and Y are independently selected from hydrogen, chloro, or fluoro; Z is hydrogen, bromo, iodo, nitro, amino, or methylsulfonylamino; R is hydrogen or difluoromethyl; and R
1
is C
1
to C
12
alkyl.
More preferred species of amidrazone (A) are selected from those wherein X, Y, and R are hydrogen, Z is hydrogen, 5-nitro, or 5-amino, and R
1
is methyl, ethyl, or propyl; wherein X and R are hydrogen, Y is 4-chloro, Z is hydrogen or 5-nitro, and R
1
is methyl, ethyl, or propyl; wherein X is 2-chloro or 2-fluoro, Y, Z, and R are hydrogen, and R
1
is methyl, ethyl, or propyl; or wherein X is 2-chloro or 2-fluoro, Y is 4-chloro, Z is hydrogen, 5-bromo, 5-iodo, or 5-nitro, R is hydrogen, and R
1
is methyl, ethyl, or propyl.
Most preferred species of amidrazone (A) are selected from those wherein X, Y, Z and R are hydrogen, and R
1
is methyl; or wherein X is 2-fluoro, Y is 4-chloro, Z and R are hydrogen, and R
1
is methyl.
For conducting the carbonylation of amidrazone (A), the use of at least one suitable organic solvent is preferably employed.
Preferred organic solvents, both polar and apolar, useful in the process of the present invention include halogenated solvents, for example, such as, without limitation, chlorobenzene, carbon tetrachloride, bromodichloromethane, dibromochloromethane, bromoform, chloroform, bromochloromethane, butyl chloride, dichloromethane, tetrachloroethylene, trichloroethylene, 1,1,1-trichloro-ethane, 1,1,2-trichloroethane, 1,1-dichloroethane, 2-chloropropane, hexafluorobenzene, 1,2,4-trichlorobenzene, 1,2-dichlorobenzene, fluorobenzene and other halogenated solvents known in the art.
Preferred polar organic solvents include ethers, for example, such as, without limitation, dimethoxymethane, THF, 1,3-dioxane, 1,4-dioxane, furan, diethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, triethylene glycol dimethyl ether, tert.-butyl ethyl ether, tert.-butyl methyl ether and other ether solvents known in the art. Other polar organic solvents useful in the context of the present invention include, for example, without limitation, propionitrile, ethyl formate, methyl acetate, hexachloroacetone, acetone, ethyl methyl ketone, ethyl acetate, nitromethane, nitrobenzene, glymes, and other polar solvents known in the
FMC Corporation
FMC Corporation
Morris Patricia L.
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