4-Methylpridazin-3-one compounds of the formula: ##STR1## [wherein, X represents a hydrogen or fluorine atom, and Y represents a hydrogen atom, C.sub.1 -C.sub.6 alkoxy, C.sub.3 -C.sub.6 alkoxy or C.sub.3 -C.sub.6 alkyloxy group] are produced by reacting 4-cyanopyridazin-3-one compounds of the formula: ##STR2## with a methylating agent. Therefore, the above 4-cyanopyridazin-3-one compounds are useful for producing the above herbicidal 4-methylpyridazin-3-one compounds as intermediates.

FIELD OF THE INVENTION 
The present invention relates to 
4-cyano-2-substitutedphenyl-5-trifluoromethylpyridazin-3-one compounds, 
method for producing them and method to produce 
4-methyl-2-substitutedphenyl-5-trifluoromethylpyridazin-3-one compounds 
that utilize them. 
BACKGROUND OF THE INVENTION 
It has been known that 4-methylpyridazin-3-one compounds of the formula 
(I): 
##STR3## 
[wherein, X represents a hydrogen or fluorine atom, and Y represents a 
hydrogen atom, C.sub.1 -C.sub.6 alkoxy, C.sub.3 -C.sub.6 alkenyloxy or 
C.sub.3-C.sub.6 alkynyloxy group] have excellent herbicidal activity 
(International patent publication No. WO97/07104), and it has been 
demanded to develop an effective method to produce these 
4-methylpyridazin-3-one compounds. 
SUMMARY OF THE INVENTION 
The present invention provides an excellent method to produce 
4-methylpyridazin-3-one compounds of the formula (1), 
4-cyanopyridazin-3-one compounds of the following (II): 
##STR4## 
[wherein X and Y represent the same definitions as above] useful as 
intermediates in the case of producing 4-methylpyridazin-3-one compounds 
of the formula (I), and a method to produce 4-cyanopyridazin-3-one 
compounds of the formula (II) (hereinafter, "the present compound(s)"), 
which comprises reacting the present compound with a methylating agent. 
DETAILED DESCRIPTION OF THE INVENTION 
In the present invention, and for what Y represents, suitable examples of 
C.sub.1 -C.sub.6 alkoxy groups include methoxy, ethoxy, propoxy, 
isopropoxy, butoxy, isobutoxy, t-butoxy (hereinafter, "t" intends 
tertiary), amyloxy, isoamyloxy, t-amyloxy groups; C.sub.3 -C.sub.6 
alkenyloxy groups include allyloxy, methallyloxy, 1-methyl-2-propenyloxy, 
3-butenyloxy, 2-butenyloxy, 3-methyl-2-butenyloxy, 2-methyl-3-butenyloxy 
groups; and C.sub.3 -C.sub.6 alkynyloxy groups include propargyloxy, 
1-methyl-2-propynyloxy, 2-butynyloxy, 1,1-dimethyl-2-propynyloxy. 
The following explains a method to produce the present compounds. The 
present compounds may be produced by reacting the hydrazone compound of 
the formula (III): 
##STR5## 
[wherein, X and Y represent the same definitions as above] with the 
cyanoacetate ester of the formula (IV) 
EQU NCCH.sub.2 COOR.sup.1 
[wherein, R.sup.1 represents a C.sub.1 -C.sub.6 alkyl group] in the 
presence of a base (hereinafter, procedure #1). 
Said reaction is performed within or without a solvent. The range of the 
reaction temperature is usually from 0 to 200.degree. C. and has the range 
of the reaction time is usually instantaneous to 240 hours. 
The amount of the reactants cooperating in the reaction is the rate of 1 to 
10 moles of the cyanoacetate ester of the formula (IV), per 1 mole of the 
hydrazone compound of the general formula (III), and the base is at the 
rate of catalytic amount to an excess, preferably 0.01 to 50 moles, more 
preferably 0.1 to 20 moles per 1 mole of the hydrazone compound. 
Suitable cyanoacetate esters include, for example, methyl cyanoacetate, 
ethyl cyanoacetate, propyl cyanoacetate, butyl cyanoacetate, amyl 
cyanoacetate. 
Suitable bases include organic bases, for example, amines such as 
dialkylanilines (e.g. N, N-dimethylaniline, N, N-diethylaniline), 
piperidine, morpholine, pyrrolidine, diethylamine, diisopropylamine, 
triethylamine, diisopropylethylamine, tri-n-propylamine, tri-n-butylamine, 
benzyldimethylamine, phenethyldimethylamine, N-methylmorpholine, 
1,8-diazabicyclo[5.4.0]undec-7-ene, 1,5-diazabicyclo [4.3.0]non-5-ene, 
1,4-diazabicyclo[2.2.2]octane; and nitrogen-containing aromatic 
heterocycles such as pyridine, quinoline, isoquinoline, 
4-dimethylaminopyridine, 2-picoline, 3-picoline, 4-picoline, 2,3-lutidine, 
2,4-lutidine, 2,5-lutidine, 2,6-lutidine, 3,4-lutidine, 3,5-lutidine, 
3-chloropyridine, 2-ethyl-3-methylpyridine, 5-ethyl-2-methylpyridine; and 
mixtures thereof. 
Suitable solvents include, for example, aliphatic hydrocarbons such as 
hexane, heptane, octane, ligroin and petroleum ether; aromatic 
hydrocarbons such as benzene, toluene, xylene and mesitylene; halogenated 
aliphatic hydrocarbons such as dichloromethane, chloroform, carbon 
tetrachloride, 1,2-dichloroethane and 1,1,1-trichloroethane; halogenated 
aromatic hydrocarbons such as chlorobenzene, dichlorobenzene, 
trichlorobenzene and benzotrifluoride; ethers such as 1,4-dioxane, 
tetrahydrofuran, diethyl ether, ethyleneglycol dimethyl ether and methyl 
t-butyl ether; nitriles such as acetonitrile, propionitrile and 
butylonitrile; esters such as ethyl formate, ethyl acetate, propyl acetate 
and butyl acetate; alcohols such as methanol, ethanol, propanol, 
isopropanol, butanol and t-butanol; acid amides such as 
N,N-dimethylformamide and N,N-dimethylacetoamide; sulfur-containing 
compounds such as dimethylsulfoxide and sulfolan; and mixtures thereof 
The reaction mixture after the reaction is subjected to work-up procedure 
such as directly progressing to concentrating operations, or 
concentrations wherein the reaction mixture is poured into water, 
extracted with an organic solvent and then has the organic layer dried may 
be performed, and when necessary, the obtained product may be purified by 
recrystallization or column chromatography to obtain the 
4-cyanopyridazin-3-one compound of the formula (II). 
The hydrazone compound of the formula (III) is known from International 
patent publication No. WO97/07104, and may be produced by complying to the 
method disclosed in said patent publication. 
Moreover, in view of the present compounds employing a herbicidal activity, 
the present compound is not only useful as the synthesizing intermediate 
of 4-methylpyridazin-3-one compounds (I), but is also useful for 
herbicide. 
Subsequently, examples of the present compounds that are obtained from 
procedure #1 are set forth in Table 1, but does not limit the present 
compound. 
Examples of the present compound: 
##STR6## 
are set forth in the following table. 
TABLE 1 
______________________________________ 
Compound Nos. 
X Y 
______________________________________ 
1-1 F H 
1-2 F OCH.sub.3 
1-3 F OC.sub.2 H.sub.5 
1-4 F OC.sub.3 H.sub.7 
1-5 F OCH(CH.sub.3).sub.2 
1-6 F OC.sub.4 H.sub.9 
1-7 F OCH.sub.2 CH(CH.sub.3).sub.2 
1-8 F OCH(CH.sub.3)C.sub.2 H.sub.5 
1-9 F OC(CH.sub.3).sub.3 
1-10 F OCH.sub.2 CH.dbd.CH.sub.2 
1-11 F OCH(CH.sub.3)CH.dbd.CH.sub.2 
1-12 F OCH.sub.2 C(CH.sub.3).dbd.CH.sub.2 
1-13 F OCH.sub.2 C.tbd.CH 
1-14 F OCH(CH.sub.3)C.tbd.CH 
1-15 H H 
1-16 H OCH.sub.3 
1-17 H OC.sub.2 H.sub.5 
1-18 H OC.sub.3 H.sub.7 
1-19 H OCH(CH.sub.3).sub.2 
1-20 H OC.sub.4 H.sub.9 
1-21 H OCH.sub.2 CH(CH.sub.3).sub.2 
1-22 H OCH(CH.sub.3)C.sub.2 H.sub.5 
1-23 H OC(CH.sub.3).sub.3 
1-24 H OCH.sub.2 CH.dbd.CH.sub.2 
1-25 H OCH(CH.sub.3)CH.dbd.CH.sub.2 
1-26 H OCH.sub.2 C(CH.sub.3).dbd.CH.sub.2 
1-27 H OCH.sub.2 C.tbd.CH 
1-28 H OCH(CH.sub.3)C.tbd.CH 
______________________________________ 
Subsequently, a method to produce the 4-methylpyridazin-3-one compounds of 
the formula (I) by reacting the present compounds with a methylating agent 
is explained (hereinafter, procedure #2). 
Procedure #2 is performed usually within a solvent. The range of the 
reaction time is usually from instantaneous to 24 hours, and the range of 
the reaction temperature depend on the sort of the methylation agent that 
is cooperating in the reaction, but is usually from -78 to 100.degree. C. 
The amount of the reactant that cooperates in the reaction is the rate of 1 
to 10 mole of the methylating agent per 1 mole of the present compound. 
The methylating agent in the present means the methylating agent for 
electrophiles, namely nucleophilic methylating agent. Therefore, typical 
examples of said methylating agent are organometalic methylating agents 
such as methyl Grignard reagents (e.g. methylmagnesium chloride, 
methylmagnesium bromide, methylmagnesium iodide), methylcopper reagents 
(e.g. dimethylcopper lithium) and methyllithium. 
Furthermore, copper iodide, cerium trichloride, hexamethylphosphoric 
triamide, tetramethylethylenediamine and the like may be optionally added 
for the reaction. 
Examples of the solvents include aliphatic hydrocarbons such as hexane, 
heptane, octane, ligroin and petroleum ether; aromatic hydrocarbons such 
as benzene, toluene, xylene and mesitylene; ethers such as 1,4-dioxane, 
tetrahydrofuran, diethyl ether, ethyleneglycol dimethyl ether, methyl 
t-butyl ether, diisopropyl ether and dibutyl ether; and mixtures thereof. 
The reaction mixture after the reaction, usually, subjected to work-up 
procedure such as concentrations wherein the reaction mixture is poured 
into water, extracted with an organic solvent and then has the organic 
layer dried may be performed, and the obtained product may be optionally 
purified by recrystallization or column chromatography to afford the 
4-methylpyridazin-3-one compound of the formula (I). 
Subsequently, examples of the compound that is produced from procedure #2 
are given in Table 2. 
Examples of the compound of the formula (I): 
##STR7## 
are set forth in the following tables. 
TABLE 2 
______________________________________ 
Compound Nos. 
X Y 
______________________________________ 
2-1 F H 
2-2 F OCH.sub.3 
2-3 F OC.sub.2 H.sub.5 
2-4 F OC.sub.3 H.sub.7 
2-5 F OCH(CH.sub.3).sub.2 
2-6 F OC.sub.4 H.sub.9 
2-7 F OCH.sub.2 CH(CH.sub.3).sub.2 
2-8 F OCH(CH.sub.3)C.sub.2 H.sub.5 
2-9 F OC(CH.sub.3).sub.3 
2-10 F OCH.sub.2 CH.dbd.CH.sub.2 
2-11 F OCH(CH.sub.3)CH.dbd.CH.sub.2 
2-12 F OCH.sub.2 C(CH.sub.3).dbd.CH.sub.2 
2-13 F OCH.sub.2 C.tbd.CH 
2-14 F OCH(CH.sub.3)C.tbd.CH 
2-15 H H 
2-16 H OCH.sub.3 
2-17 H OC.sub.2 H.sub.5 
2-18 H OC.sub.3 H.sub.7 
2-19 H OCH(CH.sub.3).sub.2 
2-20 H OC.sub.4 H.sub.9 
2-21 H OCH.sub.2 CH(CH.sub.3).sub.2 
2-22 H OCH(CH.sub.3)C.sub.2 H.sub.5 
2-23 H OC(CH.sub.3).sub.3 
2-24 H OCH.sub.2 CH.dbd.CH.sub.2 
2-25 H OCH(CH.sub.3)CH.dbd.CH.sub.2 
2-26 H OCH.sub.2 C(CH.sub.3).dbd.CH.sub.2 
2-27 H OCH.sub.2 C.tbd.CH 
2-28 H OCH(CH.sub.3)C.tbd.CH 
______________________________________ 
The compounds obtained from procedure #2 are useful for herbicide when 
complying to International patent publication No. WO97/07104. Furthermore, 
for said compound, and since it is possible to derive other substituted 
4-methylpyridazin-3-one compounds from International patent publication 
No. WO97/07104 by using the method disclosed in said patent publication, 
are also effectively used as an intermediate for said substituted 
4-methylpyridin-3-one compounds.

EXAMPLES 
The present invention is specifically explained by disclosing examples 
below. 
1) Production Examples of the Present Compounds (Procedure #1) 
Production Example 1-1 
After 0.281 g of 3, 3, 3-trifluoro-2-oxopropanal 
1-(4-chlorophenylhydrazone) was dissolved in 5 mL of pyridine, 0.304 g of 
ethyl cyanoacetate was added to the pyridine solution, which was followed 
by stirring for 5 hours at 110.degree. C. After cooling to room 
temperature, the reaction mixture was poured into 3N-hydrochloric acid and 
extracted with diethyl ether. After the organic layer was washed with 
aqueous saturated sodium bicarbonate and concentrated, the residue was 
subjected to silica gel column chromatography (eluent: ethyl 
acetate/hexane =1/9), and furthermore recrystallized from a solvent 
mixture (toluene/hexane =1/3) to afford 0.234 g of 
2-(4-chlorophenyl)-4-cyano-5-trifluoromethylpyridazin-3-one (The present 
compound 1-15). .sup.1 H-NMR (300 MHz, CDCl.sub.3).delta.(ppm): 7.49(2H, 
d, J=8.8 Hz), 7.61 (2H, d, J=8.8 Hz), 8.19 (1H,s) 
Production Example 1-2 
After 1.0 g of 3, 3, 3-trifluoro-2-oxopropanal 
1-(4-chloro-2-fluorophenylhydrazone) was dissolved in 10 mL of pyridine, 
0.8 mL of ethyl cyanoacetate and 0.5 mL of piperidine were added to the 
pyridine solution, which was followed by stirring for 3 days at room 
temperature. After pouring into water, the reaction solution was extracted 
with ethyl acetate. After the organic layer was washed with aqueous 
saturated sodium chloride, dried over anhydrous magnesium sulfate and 
concentrated, the residue was subjected to silica gel column 
chromatography (eluent: ethyl acetate/hexane =4/1), and thin-layer 
chromatography (eluent: ethyl acetate/hexane =5/1) to afford 0.28g of 
2-(4-chloro-2-fluorophenyl)-4-cyano-5-trifluoromethylpyridazin-3-one (The 
present compound 1-1). 
.sup.1 H-NMR (300 MHz, CDCl.sub.3).delta.(ppm): 7.31-7.41(3H, m), 8.19 
(1H,s) 
Production Example 1-3 
After 4.345 g of 3, 3, 3-trifluoro-2-oxopropanal 
1-(4-chloro-2-fluoro-5-isopropoxyphenylhydrazone) was dissolved in 20 mL 
of pyridine, 2.1 mL of ethyl cyanoacetate was added to the pyridine 
solution, which was followed by stirring for 4 hours at 120.degree. C. 
After cooling to room temperature, the reaction solution was poured into 
3N-hydrochloric acid and extracted with diethyl ether. After the organic 
layer was washed with aqueous saturated sodium bicarbonate and 
concentrated, the residue was subjected to silica gel column 
chromatography (eluent: ethyl acetate/hexane=2/8) to afford 2.858 g of 
2-(4-chloro-2-fluoro-5-isopropoxyphenyl)-4-cyano-5-trifluoromethylpyridazi 
n-3-one (The present compound 1-5). 
.sup.1 H-NMR (250 MHz, CDCl.sub.3).delta.(ppm): 1.40(6H, d, J=6.1 Hz), 4.49 
(1H, hp, J=6.1 Hz), 6.97 (1H,d, J=6.5 Hz), 7.35 (1H, d, J=9.3 Hz), 8.20 
(1H,s) 
2) Examples to Produce 4-methylpyridazin-3-one from the Present Compound 
(Procedure #2) 
Production Example 2-1 
After 3.0 g of 2-(4-chlorophenyl)-4-cyano-5-trifluoromethylpyridazin-3-one 
(The present compound 1-15) is dissolved in 30 mL of anhydrous 
tetrahydrofuran, 4.0 mL of methylmagnesium bromide (3.0M diethyl ether 
solution) is dropped to the tetrahydrofuran solution at 0.degree. C. and 
stirred for hour. Afterwards, the reaction solution is poured into diluted 
hydrochloric acid, and extracted with ethyl acetate. The organic layer is 
washed, in order, with water and aqueous saturated sodium chloride. After 
drying over anhydrous magnesium sulfate and concentrated, the residue is 
subjected to silica gel column chromatography to afford 
2-(4-chlorophenyl)-4-methyl-5-trifluoromethylpyridazin-3-one. 
Production Example 2-2 
After 3.18 g of 
2-(4-chloro-2-fluorophenyl)-4-cyano-5-trifluoromethylpyridazin-3-one (The 
present compound 1-1) is dissolved in 30 mL of anhydrous tetrahydrofuran, 
4.0 mL of methylmagnesium bromide (3.0M diethyl ether solution) is dropped 
to the tetrahydrofuran solution at 0.degree. C. and stirred for 1 hour. 
Afterwards, the reaction solution is poured into diluted hydrochloric 
acid, and extracted with ethyl acetate. The organic layer is washed, in 
order, with water and aqueous saturated sodium chloride. After drying over 
anhydrous magnesium sulfate and concentrated, the residue is subdued to 
silica gel column chromatography to afford 
2-(4-chloro-2-fluorophenyl)-4-methyl-5-trifluoromethylpylidazin-3-one. 
Production example 2-3 
After 1.035 g of 
2-(4-chloro-2-fluoro-5-isopropoxyphenyl)-4-cyano-5-trifluoromethylpyridazi 
n-3-one (The present compound 1-5) was dissolved in 6.0 mL of 
tetrahydrofuran, 3.1 mL of a diethyl ether solution of methylmagnesium 
iodide (0.98M diethyl ether solution) was added to the tetrahydrofuran 
solution at 0.degree. C. and stirred for 20 min under a nitrogen stream. 
Afterwards, the reaction solution was poured into 3N-hydrochloric acid and 
extracted with ethyl acetate. After the organic solvent was washed with 
aqueous saturated sodium bicarbonate and concentrated, the residue was 
subjected to silica gel column chromatography (eluent: ethyl 
acetate/hexane=1/9) to afford 0.467 g of 
2-(4-chloro-2-fluoro-5-isopropoxyphenyl)-4-methyl-5-trifluoromethylpyridaz 
in-3-one (compound 2-5).