JPS5826724B2 - 1-thiadiazolyl-6-acyloxytetrahydropyrimidinone - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel herbicidal composition, more particularly to a herbicidal composition comprising an inert carrier and, as an essential active ingredient, a compound represented by the following formula in an amount toxic to weeds: The present invention relates to a drug composition.

As used herein, the term 6-lower'' refers to straight or branched carbon chains of up to 6 carbon atoms.

The compounds of this invention are unexpectedly useful as herbicides.

which can be prepared by reacting the corresponding compounds of the invention in which R3 is hydrogen with an acid anhydride of the formula containing R4 as described above in the presence of a catalytic amount of toluenesulfonic acid. It is.

In this reaction, the reactants and catalyst are mixed in an inert organic reaction solvent at room temperature, and then the reaction mixture is heated in a steam bath at a temperature of 50° to 90°C with stirring for 1/2 to 4 hours. Implemented by

Thereafter, the desired product can be obtained by filtration if it forms a precipitate, or by distillation if it is soluble in the organic reaction solvent.

Optionally, an acid anhydride may be used as a solvent for the compound of formula (1), omitting the use of an inert solvent as a reaction solvent.

When a lower alkali phosphoric acid anhydride is used, water may be added to the reaction mixture to precipitate the desired product upon completion of the reaction.

The product may then be purified by conventional methods such as recrystallization.

It can also be prepared by reacting with an acid halide in the presence of an acid acceptor such as a tertiary amine.

If the desired anhydride of formula (1) is not available, it may be used as a method for production.

This reaction involves adding an acid chloride of formula (2) with stirring into a solution of an equimolar amount of a compound of formula (2) in an inert solvent in the presence of an acid acceptor at a temperature of about 10° to 30°C. This can be done by adding slowly.

After the addition is complete, the reaction mixture may be heated to a temperature up to reflux to ensure completion of the reaction.

The desired product is then removed by first filtering the reaction mixture to remove the acid acceptor chloride, and then, if the product is soluble, leaving a pool of solvent or forming a precipitate.
It can be recovered by one filtration and the accompanying washing and purification.

Compounds of the present invention in which R3 is hydrogen, R1 and R2 are as previously described, and R5 and R6 are methyl or ethyl, are dissolved in an aqueous dilute acidic reaction solvent for about 10 to about 60% It can be produced by heating for minutes.

Temperatures from about 70° C. to the reflux temperature of the reaction mixture may be used.

The reaction mixture contains about 0% of a dilute aqueous inorganic acid solution such as hydrochloric acid.
．． It can be included at a concentration of 5 to about 5 percent.

Upon completion of the reaction, the desired product may be recovered as a precipitate by cooling the reaction mixture.

This product may be used as is with N or may be further purified by conventional means such as recrystallization and the like.

The compound of formula (II) is prepared by combining the incyanate dimer-molar amounts as also mentioned above with R2, R2 as already mentioned.
5 and R6 in about two molar amounts.

This reaction can be carried out by heating the mixture of the incyanate dimer and acetal in an inert organic reaction solvent such as benzene at the reflux temperature of the reaction mixture.

Heating to reflux may be continued for about 2 to about 30 minutes to ensure completion of the reaction.

After this, the desired product can be recovered by distillation of the reaction solvent, used in bulk, or further purified by standard methods in the art.

The isocyanate dimer of formula (■) has R as described above.
Thiadiazoles of the formula containing 1 can be prepared by reacting with phosgene.

The reaction is carried out by adding a slurry or solution of the thiadiazole in a suitable organic solvent such as ethyl acetate to a saturated solution of phosgene in an organic solvent such as ethyl acetate.
can be done.

The resulting mixture may then be stirred at room temperature for about 4 to about 24 hours.

The reaction mixture can then be purged with nitrogen gas to remove unreacted phosgene.

Thereafter, the desired product may be recovered by one filtration if it forms a precipitate, or by distillation of the organic solvent used if it is soluble.

This product can be used as is or may be further purified if necessary.

Representative thiadiazoles of formula (1) useful in the preparation of compounds of the invention include, for example, 5-methyl-2-aminonote 3,4
-Thiadiazole, 5-ethyl-2-aminonaute 3,4
-thiadiazole, 5-propyl-2-aminoto 3.
4-thiadiazole, 5-allyl-2-ami7 note 3
・4-thiadiazole, 5-pen)-3-uniru-2-aminoto 3,4-thiadiazole, 5-chloromethyl-2
-Aminot 3,4-thiadiazole, 5-β-chloroethyl-2-ami/-1,3,4-thiadiazole, 5
-γ-chloropropyl-2-aminoto 3, 4-thiadiazole, 5-trichloromethyl-2-aminoto 3.
4-thiadiazole, etc.

If the acetal of formula (2) is not readily available, it can be prepared by reacting an amine of the formula containing R2 as described above with dimethyl or diethyl acetal of β-bromopropionaldehyde.

This reaction is carried out by mixing about 1 to about 2 moles of the amine of formula (1) with 1 mole of the acetal of β-bromopropionaldehyde in an equimolar ratio of X in an inert organic reaction solvent such as methanol. can be done.

The reaction mixture may then be heated to reflux for about 4 to about 8 hours.

The reaction mixture is then allowed to cool to room temperature and a sufficient amount of alkali metal hydroxide or carbonate is added to neutralize the reaction mixture.

Stirring may be continued for up to about 24 hours at room temperature to ensure completion of the reaction.

Thereafter, the desired product can be obtained by passing the reaction mixture once and distilling the first solution under reduced pressure.

Representative compounds of formula (1) include methylamine, ethylamine, propylamine, isopropylamine, η-butylamine, 1-butylamine, pentylamine, hexylamine, and the like.

Representative suitable acid anhydrides of formula (2) include acetic anhydride, propionic anhydride, butanoic anhydride, pentanoic anhydride, hexanoic anhydride, and the like.

Representative suitable acid chlorides of formula (1) useful in the preparation of the compounds of this invention are the acid halides of the same acids mentioned above for the acid anhydrides.

Methods by which the compounds of the present invention can be prepared are further illustrated in detail in the Examples below.

Reference Example 1 Preparation of 5-methyl-1,3,4-thiadiazole-2yl isocyanate dimer A saturated solution of phosgene in ethyl acetate (100 ml) is placed in a glass reactor equipped with a mechanical stirrer. .

A slurry of 5-methy#-2-'7mi/-1-3-4-thiadiazole (40 grams) in ethyl acetate (300 ml) was added to the reaction vessel, and the resulting mixture was stirred for about 16 hours to remove the precipitate. Formation occurs.

The reaction mixture is then purged with nitrogen gas to remove unreacted phosgene.

The cleaned mixture is then filtered to obtain a precipitate. The precipitate is then recrystallized to yield the desired product 5-methyl-1,3,4
- Thiadiazol-2-yl isocyanate dimer.

Reference Example 2 Production of dimethyl acetal of 3-methylaminopropionaldehyde Methylamine (1.0 mol), dimethyl acetal of 3-bromopropionaldehyde (0.5 mol) and methanol (100rrLl) were mixed with a mechanical stirrer (mechanical stirrer). Place in a glass reaction vessel equipped with a thermometer and a reflux condenser.

The reaction mixture is heated to reflux with stirring for about 4 hours.

The reaction mixture is then cooled to room temperature and hydroxide (20 grams) is added.

The reaction mixture is then stirred for about an additional 8 hours.

Then, the reaction mixture is filtered once, and the F solution is distilled under reduced pressure to obtain the desired product, dimethyl acetal of 3-methylaminopropionaldehyde.Reference Example 3 3-[1-Methyl-3-(5-methyl-1・Production of dimethyl acetal of 3,4-thiadiazol-2-yl)ureido]propionaldehyde 5-methyl-1,3,4-thiadiazol-2-yl
Isocyanate dimer (0,05 mol), dimethyl acetal of 3-methylamino-propionaldehyde (0
, 1 mol) and benzene (60 mO) are placed in a glass reactor equipped with a mechanical stirrer and a reflux condenser.

The reaction mixture is heated to reflux for about 15 minutes.

Thereafter, benzene is distilled from the mixture under reduced pressure to give a solid product as a residue.

This residue is then recrystallized to yield the desired product 3-[1-
The dimethyl acetal of methyl-3-(5-methyl-1,3,4-thiadiazol-2-yl)ureido]propionaldehyde is obtained.

Reference example 4 Tetrahydro-1-(5-methyl-1,3,4-thiadiazol-2-yl)-3-methyl-6-hydroxy-
Preparation of 2(IH)-pyrimidinone 3-[1-Methyl-3-(5-methyl-1,3,4-thiadiazol-2-yl)ureido] dimethyl acetal of propionaldehyde (15 grams), water (400 grams)
ml) and hydrochloric acid (4 mA') are placed in a glass reaction vessel equipped with a mechanical stirrer, a thermometer and a reflux condenser.

The reaction mixture is heated to reflux for about 15 minutes.

The reaction mixture is then filtered hot and a precipitate forms when the f liquid is cooled.

The precipitate was collected by filtration, dried and recrystallized to yield the desired product ditrahydro-1(5-methyl-1,3,4-thiadiazol-2yl)-3-methyl-6-hydroxy-2(IH )-gives pyrimidinone.

Example 1 Preparation of tetrahydro-1-(5-methyl-1,3,4-thiadiazol-2-yl)-3-methyl-6-acetyloxy-2(LH)-pyrimidinone Tetrahydro-1-(5-methyl- 1,3,4-thiadiazol-2-yl)-3-methyl-6=hydroxy-
2(LH)-pyrimidinone (0.1 mol); acetic anhydride (
0.11 mol), toluenesulfonic acid (0.05 g) and benzene (100 rILl) in a mechanical stirrer (
Place in a glass reaction vessel equipped with a mechanical stirrer (mechanical stirrer) and a thermometer.

The reaction mixture is heated with stirring on a water bath for about 2 hours.

The reaction mixture is then cooled to room temperature and the solvent is removed under reduced pressure to give a residue.

Recrystallization of the residue yields the desired product tetrahydro-1
-(5-Methyl-1,3,4-thiadiazol-2-yl)-3-methyl-6-acetyloxy-2(LH)-pyrimidinone is obtained.

Reference Example 5 Preparation of 5-methoxylate 3,4-thiadiazol-2-yl isocyanate dimer A saturated solution of phosgene in ethyl acetate (roomO) is placed in a glass reaction vessel equipped with a mechanical stirrer.

A slurry of 5-methoxy-2-aminoto 3,4-thiadiazole (40 grams) in ethyl acetate (300 yd) is added to the reaction vessel and the resulting mixture is stirred for about 16 hours, causing a precipitate to form.

The reaction mixture is then purged with nitrogen gas to remove unreacted phosgene.

The clarified mixture is then filtered to obtain a precipitate.

The precipitate is then recrystallized to give the product 5-methoxide 3,4-thiadiazol-2-yl isocyanate dimer.

Reference Example 6 Production of dimethyl acetal of 3-ethylaminopropionaldehyde Ethylamine (2.0 mol), dimethyl acetal of 3-bromopropionaldehyde (1.0 mol) and methanol (100rrLl) were mixed with a mechanical stirrer. , into a glass reaction vessel equipped with a thermometer and a reflux condenser.

The reaction mixture is heated to reflux with stirring for about 5 hours.

After this time the reaction mixture was cooled to room temperature and sodium hydroxide (
20 grams).

The reaction mixture is then stirred for an additional approximately 12 hours.

The reaction mixture is then filtered, and the first solution is distilled under reduced pressure to obtain the desired product, dimethyl acetal of 3-ethylaminopropionaldehyde.

Reference example 7 3-('1-(ethyl-3-(5-methoxylate 3, 4
-Thiadiazo-/L/-2-yl) Preparation of dimethyl acetal of ureidopropionaldehyde 5-methoxylate 3,4-thiadiazol-2-yl
Isocyanate dimer (0,05 mol), dimethyl acetal of 3-ethylamino-propionaldehyde (0
, 1 mol) and benzene (60 ml) are placed in a glass reaction vessel equipped with a mechanical stirrer and a reflux condenser.

The reaction mixture is heated to reflux for about 15 minutes.

After this time, the benzene is removed from the mixture under reduced pressure to give a solid product as a residue.

This residue is then crystallized to obtain the desired product, the dimethyl acetal of 3-[1-ethyl-3-(5-methoxyto-3,4-thiadiazol-2-yl)ureidopropionaldehyde.

Reference example 8 Tetrahydro-1-(5-methoxy-1,3,4-thiadiazol-2-yl)-3-ethyl 6-hydroxy-
Production of 2(IH)-pyrimidinone 3-[1-ethyl-3-(5-methoxy-1,3,4-
Thiadiazol-2-ylnoureide] Dimethyl acetal of propionaldehyde (15 grams), water (40 grams)
wLl) and hydrochloric acid (4 m0) into a glass reaction vessel equipped with a thermometer, stirrer and reflux condenser.

The reaction mixture is heated to reflux for about 15 minutes.

The reaction mixture is then filtered while hot, and when the first solution is cooled, a precipitate is formed.

The precipitate is collected by filtration, dried and recrystallized to yield the desired product tetrahydro-1-(5-methoxide 3°4-thiadiazol-2-yl)-3ethyl-6-hydroxy-
2(lH)-pyrimidinone is obtained.

Reference Example 9 Production of tetrahydro-1-(5-methoxy-1,3,4-thiadiazol-2-yl)-3-ethyl-6-propionyloxy-2(IH)pyrimidinone Tetrahydro-1-(5-methoxy -1,3,4-thiadiazol-2-yl)-3-ethyl-6-hydroxy-2(IH)-pyrimidinone (0,1 mol), propionic anhydride (0,11 mol), toluenesulfonic acid (0, 0
5 grams) and hibenzene (1 oomJ) in a glass reaction vessel equipped with a mechanical stirrer and a thermometer.

The mixture is heated on a steam bath for about 2 hours with stirring.

After this time, the reaction mixture is cooled to room temperature and the solvent is distilled off under reduced pressure to give a residue.

Recrystallization of the residue yields the desired product tetrahydro-1
-(5-methoxy-1,3,4-thiadiazole-2-
yl)-3-ethyl-6-propionyloxy-2(IH
)-pyrimidinone is obtained.

Reference Example 10 Preparation of 5-methylthio-1,3,4-thiadiazol-2-yl isocyanate dimer A saturated solution of phosgene in ethyl acetate (1007d) was placed in a glass reaction vessel equipped with a mechanical stirrer. put in.

5-Methylthio-2 in ethyl acetate (300 TILl)
A slurry of -aminodo 3,4-thiadiazole (45 grams) is added to the reaction vessel and the resulting mixture is stirred for about 16 hours to form a precipitate.

The reaction mixture is then purged with nitrogen gas to remove unreacted phosgene.

The clarified mixture is then filtered to collect the precipitate.

The precipitate is then recrystallized to obtain the desired product, 5-methylthio-1,3,4-thiadiazol-2-yl isocyanate dimer.

Reference Example 11 Production of dimethyl acetal of 3-propylaminopropionaldehyde Propylamine (2.0 mol), dimethyl acetal of 3-7' lomopropionaldehyde (1.0 mol) and methanol (100 mA') were mixed with a mechanical stirrer,
Place in a glass reaction vessel equipped with a thermometer and reflux condenser.

The reaction mixture is heated to reflux with stirring for about 3 hours.

After this time, the reaction mixture is cooled to room temperature and sodium hydroxide (20 grams) is added.

The reaction mixture is stirred for an additional approximately 6 hours.

The reaction mixture is then filtered and the resulting solution is distilled under reduced pressure to obtain the desired product, dimethyl acetal of 3-propylaminopropionaldehyde.

Reference example 12 3-[1-furopyl-3-(5-methylthiotate 3,4
-Thiadiazol-2-yl)ureido] Preparation of dimethyl acetal of propionaldehyde 5-Methylthio-1,3,4-thiadiazol-2-yl isocyanate dimer (0.05 mol), dimethyl acetal of 3-propylaminopropionaldehyde (o
, imol) and benzene (60 ml) are placed in a glass reaction vessel equipped with a mechanical stirrer and a reflux condenser.

The reaction mixture is heated to reflux for about 15 minutes.

Thereafter, benzene is distilled off from the mixture under reduced pressure to obtain a solid product as a residue.

Thereafter, this residue is recrystallized to obtain the desired product, dimethyl acetal of 3-[1-propyl-3-(5-methylthio-1,3,4-thiadiazol-2-yl)ureido]propionaldehyde.

Reference Example 13 Production of tetrahydro-1-(5-methylthio-1,3,4-thiadiazol-2-yl)-3-furopyru-6-hydroxy-2(LH)-pyrimidinone 3-[1-propyl-3-( 5-methylthio=1.3.
4-thiadiazol-2-yl)ureido] dimethyl acetal of propionaldehyde (15 grams), water (
400 TILl) and hydrochloric acid (4 m) into a glass reaction vessel equipped with a mechanical stirrer, a thermometer and a reflux condenser.

The reaction mixture is heated to reflux for about 15 minutes.

Thereafter, the reaction mixture is filtered under heat, and when the first solution is cooled, a precipitate is formed.

The precipitate was separated, dried and recrystallized to obtain the desired product tetrahydro-1-(5-methylthio-1,3,4-thiadiazol-2-yl)-3-propyl-6-hydroxy-2( LH)-pyrimidine is obtained.

Reference Example 14 Production of tetrahydro-1-(5-methylthio-1,3,4-thiadiazol-2-yl)-3-propyl-6-butanoyloxy-2(LH)-pyrimidinone Tetrahydro-1-(5-methylthio -1,3,4-thiacyazol-2-yl)-3-7''ropyl 6-hydroxy-2(IH)-pyrimidinone (0,1 mol), butyric anhydride (0,11 mol), toluenesulfonic acid (O, O5
grams) and benzene (ioml) in a glass reaction vessel equipped with a mechanical stirrer and a thermometer.

The reaction mixture is heated on a steam bath with stirring for about 2 hours.

The reaction mixture is then cooled to room temperature and the solvent is evaporated under reduced pressure to give a residue.

The residue was recrystallized to give the desired product tetrahydro 1-(
5-Methylthio-1,3,4-thiadiazol-2-yl)-3-propyl-6-butaneyloxy-2 (LH)
and viridinone.

Reference example 15 5-methylsulfonyl-1,3,4-thiadiazole-
Preparation of 2-yl isocyanate dimer A saturated solution of phosgene in ethyl acetate (1001 LA) is placed in a glass reaction vessel equipped with a mechanical stirrer.

A slurry of 5-methylsulfonyl-2--y-,/-1.3.4-thiadiazole (50 grams) in ethyl acetate (30.1 rLl) was added to the reaction vessel and the resulting mixture was stirred for about 16 hours. The precipitate is then peeled.

The reaction mixture is then purged with nitrogen gas to remove unreacted phosgene.

The clarified mixture is passed through one sieve to obtain a precipitate. The precipitate was then recrystallized to yield the desired product 5-methylsulfonyl-1.
A 3,4-thiadiazol-2yl isocyanate dimer is obtained.

Reference Example 16 Production of dimethyl acecool of 3-allylaminopropionaldehyde Allylamine (1.0 mol), dimethyl acetal of 3-butylaminopropionaldehyde (0.5 mol) and methanol (looml) were mixed with a mechanical stirrer, Place in a glass reaction vessel equipped with a thermometer and reflux condenser.

The reaction mixture is heated to reflux with stirring for about 8 hours.

The reaction mixture was then cooled to room temperature and sodium hydroxide (2
0 grams).

The reaction mixture is stirred for about an additional 14 hours.

The reaction mixture is then filtered and the r liquid is distilled under reduced pressure to obtain the dimethyl acetal of the desired product, 3-allylaminopropionaldehyde.

Reference example 17 3-[1-allyl-3-(5-methylsulfonyl-1.
Production of dimethyl acetal of 3,4-thiadiazol-2-yl)ureido]propionaldehyde 5-methylsulfonyl-1,3,4-thiadiazole-
2-yl isocyanate dimer (0.05 mol), 3
-allylaminopropionaldehyde (o, 1 mol)
and benzene (6omA) into a glass reaction vessel equipped with a mechanical stirrer and a reflux condenser.

The reaction mixture is heated to reflux for about 15 minutes.

Benzene is then removed from the mixture under reduced pressure to give a solid product as a residue.

The residue is then recrystallized to obtain the desired product 3-[1-allyl-3-(5-methylsulfonyl-1,3,4-thiadiazol-2-yl)ureido]propionaldehyde in dimethyl acecool.

Reference example 18 Tetrahydro-1-(5-methylsulfonyl root 3, 4
-Thiadiazol-2-yl)-3allyl-6-hydroxy-2(LH)-pyrimidinone production 3-(t-may-3~(5-methylsulfonyl-
Dimethyl 1,3,4-thiadiazol-2-yl)ureido]propionaldehyde acecool (15 grams), water (4007 nl), and hydrochloric acid (47 rL) in a glass reaction vessel equipped with a mechanical stirrer, thermometer, and reflux condenser. insert.

The reaction mixture is heated to reflux for about 15 minutes.

The reaction is then filtered hot and the lachrymal fluid is cooled to form a precipitate.

The precipitate was separated and recrystallized after drying to give the desired product tetrahydro-1-(5-methylsulfonyl-1,3,4
-thiadiazol-2-yl)-3-allyl-6-hydroxy-2(LH)-pyrimidinone is obtained.

Reference example 19 Tetrahydro-1-(5-methylsulfonyl 3,4-
Preparation of thiadiazol-2-yl)-3allyl-6-cyclohexylcarbonyloxy-2(LH)-pyrimidinone Tetrahydro-1-(5-methylsulfonyl 3,4-
thiadiazol-2-yl)-3allyl-6-hydroxy-2(IH)-pyrimidinone (0.1 mol), cyclohexanecarboxylic anhydride (0.11 mol), toluenesulfonic acid (0.05 g) and benzene ( 100m/
Place the mixture in a glass reaction vessel equipped with a mechanical stirrer and a thermometer.

The reaction mixture is heated on a steam bath with stirring for about 2 hours.

After this time the reaction mixture is cooled to room temperature and the solvent is removed under reduced pressure to give a residue.

The residue was recrystallized to obtain the desired product tetrahydro-1-
(5-Methylsulfonyl-1,3,4-thiadiazol-2-yl)-3-allyl 6-cyclohexylcarbonyloxy-2(IH)-pyrimidinone is obtained.

Reference example 20 5-cyclopropyl-1,3,4-thiadiazole-2
-yl Isocyanate dimer production Ethyl acetate (10
A saturated solution of phosgene in 0 ml) is placed in a glass reaction vessel equipped with a mechanical stirrer.

A slurry of 5-cyclopropyl-2-aminoto 3,4-thiadiazole (50 grams) in ethyl acetate (300 TLl) is added to the reaction vessel and the resulting mixture is stirred for about 16 hours to form a precipitate.

The reaction mixture is then purged with nitrogen gas to remove unreacted phosgene.

The cleaned mixture is then passed through one pass to collect the precipitate.

The precipitate is then recrystallized to obtain the desired product 5-cyclopropyl-1,3,4-thiadiazol-2-yl isocyanate dimer.

Reference Example 21 Production of dimethyl acetal of 3-propargylaminopropionaldehyde Florpargylamine (2.0 mol), dimethyl acetal of 3-bromopropionaldehyde (1.0 mol)
and methanol (100 rrLl) into a glass reaction vessel equipped with a mechanical stirrer, a thermometer and a reflux condenser.

The reaction mixture is heated to reflux with stirring for about 6 hours.

After this time the reaction mixture is cooled to room temperature and sodium hydroxide (20 grams) is added.

The reaction mixture is then stirred for an additional approximately 16 hours.

The reaction mixture is then filtered, and the F solution is distilled under reduced pressure to obtain the desired product, dimethyl acetal of 3-propargylaminopropionaldehyde.

Reference example 22 3-[1-propargyl-3-(5-cyclopropyA/
-1,3,4-thiadiazol-2-yl)-ureido]Production of dimethyl acetal of propionaldehyde 5-cyclopropyl-1,3,4-thiadiazole-2
-yl isocyanate dimer (0.05 mol), 3-
Dimethyl acetal of 7'lobalgylaminopropionaldehyde (0.05 mol) and hihenzene (60 mA
) is placed in a glass reaction vessel equipped with a mechanical stirrer and a reflux condenser.

The reaction mixture is heated to reflux for about 15 minutes.

After this, benzene is removed from the reaction mixture under reduced pressure to obtain a solid product as a residue.

The residue was then recrystallized to give the desired product 3-[1-furopargyl-3-1:5-cyclopropyl-1,3,4-
Dimethyl acetal of thiadiazol-2-yl)ureido]propionaldehyde is obtained.

Reference example 23 Tetrahydro-1-(5-cyclopropyl-1, 3, 4
-thiadiazol-2-yl)-3-propargyl-6
-Production of hydroxy-2(IH)-pyrimidinone 3-[1-propargyl-3-(5-cyclopropyl-
1,3,4-thiadiazol-2-yl)ureido]propionaldehyde (15 grams), water (400711
) and hydrochloric acid (4 ml) are placed in a glass reaction vessel equipped with a mechanical stirrer, a thermometer and a reflux condenser.

The reaction mixture is heated to reflux for about 15 minutes.

The reaction mixture is then filtered hot and the lachrymal fluid is cooled to form a precipitate.

The precipitate was collected by filtration, dried and recrystallized to yield the desired product tetrahydro-1-(5-cyclopropyl-1.3
・4-thiadiazol-2-yl)3-propargyl-
6-Hydroxy-2(LH) viridinone is obtained.

Reference example 24 Tetrahydro-1-(5-cyclopropyl-1, 3, 4
-thiadiazol-2-yl)-3-propargyl-6
-Production of benzyloxy-2(IH)-pyrimidinoneTetrahydro-1-(5-cyclopropyl-1,3,4
-thiadiazol-2-yl)-3-propargyl-6
-Hydroxy-2(LH)-pyrimidinone (0.1 mol), benzoic anhydride (0.11 mol), toluenesulfonic acid (0.05 grams) and higenzene (100 ml) in a glass fitted with a mechanical stirrer and a thermometer. Place in reaction vessel.

The reaction mixture is heated on a steam bath with stirring for about 2 hours.

The reaction mixture is then cooled to room temperature and the solvent is removed under reduced pressure to give a residue.

Recrystallization of the residue yields the desired product tetrahydro-
1-(5-cyclopropyl-1.3.4thiadiazol-2-i/L/)-3-propargyl 6-benzoyloxy-2(IH)-pyrimidinone is obtained.

Reference Example 25 Preparation of 5-trifluoromethyl-1,3,4-thiadiazol-2-yl isocyanate dimer A saturated solution of phosgene in ethyl acetate (1001 rLO) is placed in a glass reactor equipped with a mechanical stirrer.

A slurry of 5-trifluoromethyl-2-aminoto 3,4-thiadiazole (45 grams) in ethyl acetate (300 TLl) is added to the reaction vessel and the resulting mixture is stirred for about 16 hours to form a precipitate.

The reaction mixture is then purged with nitrogen gas to remove unreacted phosgene.

The clarified mixture is filtered to yield 48 grams of white solid.

When this solid was recrystallized from dimethyl formaldehyde, the desired product 5-trifluoromethyl-1,3,4-
This gives the thiadiazol-2-yl isocyanate dimer.

Reference example 26 3-[1-methyl-3-(5-)lifluoromethyl-1
・Production of dimethyl acetal of 3,4-thiadiazol-2-yl)ureido]propionaldehyde 5-trifluoromethyl-1,3,4-thiadiazol-2-yl isocyanate dimer (9.5 grams),
Dimethyl of 3-methyl-aminopropionaldehyde
A mixture of acetal (5.8 grams) and benzene (59 mO) is placed in a glass reaction vessel equipped with a mechanical stirrer and a reflux condenser.

The reaction mixture is heated to reflux for about 15 minutes.

Thereafter, the mixture is freed from benzene under reduced pressure to give a solid product as a residue.

This product is recrystallized to obtain the desired product 3-[1-methyl-3-(5-)lifluoromethyl-1,3,4-thiadiazol-2-yl)ureido]propionaldehyde.

Example 2 Tetrahydro-1-(5-)lifluoromethyl-1.3
・4-thiadiazol-2-yl)-3-methyl-6-
Preparation of hydroxy-2(IH)-pyrimidinone 3-[1-methyl-3-(5-)lifluoromethyl-1
- Dimethyl acetal of 3,4-thiadiazol-2-yl)ureido]propionaldehyde (15 grams), water (400 ml) and hydrochloric acid (4 TLl) in a glass reaction vessel equipped with a mechanical stirrer, thermometer and reflux condenser. Put it in.

The reaction mixture is heated to reflux for about 15 minutes.

The reaction mixture is then filtered hot and the P solution is cooled to form a precipitate.

The precipitate is collected by filtration, dried and recrystallized to give the desired product tetrahydro-1-(5-)IJfluoromethyl-1,3,4-thiadiazol-2-yl)-3-methyl-6-. Hydroxy-2(IH)-pyrimidinone is obtained.

(Melting point 116-117°C) Example 3 Tetrahydro-1-(5-)lifluoromethyl 3.4
-Production of thiadiazol-2-yl)-3methyl-6-acetyloxy-2(LH)-pyrimidinonetetrahydro-1-(5-)lifluoromethyl 3.4
-thiadiazol-2-yl)-3methyl-6-hydroxy-2(IH)-pyrimidinone (0,1 mol), acetic anhydride (0,11 mol), toluenesulfonic acid (0,05
grams) and hibenzene (100 grams) are placed in a glass reaction vessel equipped with a mechanical stirrer and a thermometer.

The reaction mixture is heated on a steam bath with stirring for about 2 hours.

The reaction mixture is then cooled to room temperature and the solvent is removed under reduced pressure to give a residue.

The residue was recrystallized to give the desired product tetrahydro-1-
(5-)Lifluoromethyl-1,3,4-thiadiazol-2-yl)-3-methyl-6-acetyloxy-2(
LH)-pyrimidinone is obtained.

(Melting point 114-116°C) Reference example 27 Production of 5-t-butyro-3,4-thiadiazol-2-yl isocyanate dimer Ethyl acetate (109m)
A saturated solution of medium phosgene was placed in a glass reaction vessel equipped with a mechanical stirrer.

Ethyl acetate (5-t- in 3001rL0) was added to the reaction vessel.
A slurry of butyl-2-aminoto 3.4thiadiazole (10 grams) was added and the resulting mixture was stirred for about 16 hours to form a precipitate.

The reaction mixture was then purged with nitrogen gas to remove unreacted phosgene.

The clarified mixture was then filtered to give a melting point of 261°.
The desired product 5-keibutyroto 3,4-thiadiazol-2-yl isocyanate dimer was obtained as a solid having an angle of 263° from .

Reference example 28 3-[1-methyl-3-(5-t-butyroot 3,4-
Preparation of dimethyl acetal of thiadiazol-2-yl)ureido]propionaldehyde 5-tert-butyroot 3,4-thiadiazol-2-yl isocyanate dimer (6 grams), dimethyl acetal of 3-methylaminopropionaldehyde (4, 0
gram) and benzene (50 g) into a glass reaction flask equipped with a mechanical stirrer and a reflux condenser.

The reaction mixture is heated to reflux with stirring for about 5 minutes.

After this, benzene is removed from the reaction mixture to obtain a residue.

The residue is then recrystallized to obtain the desired product, the dimethyl acetal of 3-[1-methyl-3-(5-butyro-3,4-thiadiazol-2-yl)ureido]propionaldehyde.

Example 4 Tetrahydro-1-5-(t-butyroto-3,4-thiadiazol-2-yl)-3-methyl6-hydroxy-
Preparation of 2(LH)-pyrimidinone 3-[1-methyl-3-(5-t-butyroto3,4-
Dimethyl acetal of thiadiazol-2-yl)ureido]propionaldehyde (16 grams), concentrated hydrochloric acid (10 TLl), and water (500 TfLl) are placed in a glass reaction vessel equipped with a mechanical stirrer, a thermometer, and a reflux condenser.

The reaction mixture is filtered hot and the P solution is then cooled to form a precipitate.

The precipitate was collected by one filtration, dried and recrystallized to give the desired product tetrahydro-1-(5-t-butyro-3,4-
Thiadiazol-2-yl)-3-methyl-6-hydroxy-2(LH)-pyrimidinone is obtained.

(Melting point 158-160°C) Reference example 29 Production of tetrahydro-1-(5-t-butyroto-3,4-thiadiazol-2-yl)-3-methyl-6-acetyloxy-2(IH)-pyrimidinone Tetrahydro-1 -(5-tert-butyroto-3,4-thiadiazol-2-yl)-3-methyl-6-hydroxy-2(IH)-pyrimidinone (0.1 mol), acetic anhydride (0.11 mol), toluenesulfone Acid (0.05 grams) and benzene (100 mA) are placed in a glass reaction vessel equipped with a mechanical stirrer and a thermometer.

The reaction mixture is heated on a steam bath with stirring for about 2 hours.

After this, the reaction mixture is cooled to room temperature and the solvent is eluted under reduced pressure to obtain a residue.

The residue was recrystallized to obtain the desired product tetrahydro-1-(
5-tert-butyroto-3,4-thiadiazol-2-yl)-3methyl-6-acetyloxy-2(LH)-pyrimidinone is obtained.

Reference example 30 Tetrahydro-1-(5-1-lifluoromethylto3.
Preparation of 4-thiadiazol-2-yl)-3-methyl-6-benzoyloxy-2(IH)-pyrimidinone Tetrahydro-1-(5-)lifluoromethyl-1.3
・4-thiadiazol-2-yl)-3methyl-6-hydroquine-2(IH)-pyrimidinone (0.05 mol)
, triethylamine (0.06 mol) and benzene (5
0 m) into a glass reaction vessel equipped with a mechanical stirrer, a thermometer and a reflux condenser.

Add plenty of benzoyl chloride (0.05 mo/1/) while stirring.

After the addition is complete, the reaction mixture is heated to reflux for about 30 minutes with continued stirring.

Thereafter, the reaction mixture was filtered once, and the solvent was removed from liquid f under reduced pressure to obtain a solid residue.

Recrystallization of the residue yields the desired product tetrahydro-1
-(5-)! This gives J fluoromethyl-1,3,4-deadiazol-2-yl)-3-methyl-6-benzoyloxy-2(IH)-pyrimidinone.

Reference Example 31 Production of tetrahydro-1-(5-t-butyroute 3,4-thiadiazol-2-yl)-3-methyl-6-benzoyloxy-2(IH)-pyrimidinone Tetrahydro-1-(5-t-butyroute) 3,4-thiadiazol-2-yl)-3-methyl-6-hydroxy-2(IH)-pyrimidinone (0,05 mol), triethylamine (0,06 mol) and benzene (50 rrL
0 into a glass reaction vessel equipped with a mechanical stirrer, a thermometer and a reflux condenser.

Benzoyl chloride (0.05 mol) is then added dropwise with stirring.

After the addition is complete, the reaction mixture is heated to reflux for about 30 minutes with continued stirring.

Thereafter, the reaction mixture is filtered and the solvent is removed from the f solution under reduced pressure to obtain a solid residue.

Recrystallization of the residue yields the desired product tetrahydro-1
-(5-t-butyroto-3,4-thiadiazole-2-
yl)-3-methyl-6-benzoyloxy-2(LH)
- Provide pyrimidinone.

Example 5 Tetrahydroxy-1-(5-t-butyroot 3,4-
thiadiazol-2-yl)-3-mef-6-(N-
Preparation of J methylcarbamoyloxy)2 (LH)-pyrimidinone Tetrahydro-1-(5-t-butyl-1,3,4-thiadiazol-2-yl)-3-methyl-6-hydroxy-2(LH)- A mixture of pyrimidinone (42), methyl isocyanate (37717), dibrutin diacetate (2 drops), and methylene chloride (20 ml) was placed in a glass reaction vessel equipped with a reflux condenser.

The mixture was refluxed for 16 hours, the solvent was removed, and the residue was recrystallized from an inpropatol/heptane mixture to obtain the desired compound, tetrahydro-1-(5-t-butyrot 3,4-
Thiadiazol-2-yl)-3-methyl-6-(N-methylcarbamoyloxy)-2(IH)-pyrimidinone was obtained.

(Melting point 178-180℃) Elemental analysis: C13H21
N50s S as HN word-°calculated value: 47.72 6.46 21.38
(%) Actual value: 47.62 6.71 21.2
7 (%) Example 6 Tetrahydro 1-(5-)IJ fluoromethylate 3.
4-thiadiazol-2-yl)-3-methyl-6-(
Preparation of N-methylcarbamoyloxy)-2(LH)-pyrimidinoneTetrahydro-1-(5-)"J fluoromethylate 3.
4-thiadiazol-2-yl)-3-methyl-6-hydroxy-2(LH)-pyrimidinone (4z), methyl inocyanate (3TLl), dibutyltin diacetate (2 drops), and methylene chloride (20 mJl). The mixture was placed in a glass reaction vessel equipped with a reflux condenser.

The mixture was refluxed for 16 hours, the solvent was removed, and the residue was recrystallized from an isopropanol/heptane mixture to obtain the target compound, tetrahydro-1-(5-)lifluoromethyl-1.
3,4-thiadiazol-2-yl)-3-methy)v-
6-(N)f-carbamoyloxy)-2(LH)-pyrimidinone was obtained.

(Melting point 171-172℃) Elemental analysis: CIOHIOF3N503S as H
N Calculated value: 35.60 2.99 20.73 (
%) Actual value: 34.99 3.47 20.52
(%) Example 7 Preparation of tetrahydro-1-(5-ethylthio-1,3,4-thiadiazol-2-yl)-3-methyl-6-hydroxy-2(lH)-pyrimidinone 2-[1-methyl- 3-(5-ethylthio-1,3,4
-thiadiazol-2-yl)ureido] dimethyl acetal of propionaldehyde (1:l), water (20Q
lrLe) and concentrated hydrochloric acid (51 rLl) were placed in a glass reaction vessel equipped with a stirrer, thermometer and reflux condenser.

The mixture was heated under reflux for 15 minutes, filtered while hot, and then cooled to give a precipitate.

The precipitate was collected and recrystallized from hexane to obtain the target compound, tetrahydro-1-(5-ethylthio-1,3,4
-thiadiazol-2-yl)-3-methyl-6-hydroxy-2(LH)-pyrimidinone was obtained.

(Melting point 95-96℃) Elemental analysis: C9H14N40□
HN as S2 Calculated value: 39.40 5.14 20.41 (
%) Actual value: 39.06 5.12 20.65
(%) For practical use as a herbicide, the compound of the present invention is generally contained in a herbicidal composition comprising an inert carrier and a toxic amount of the compound as a herbicide.

Such herbicidal compositions, which may also be referred to as formulations, are those whose active compounds can be conveniently applied to the site of weed propagation in any required amount.

These compositions may be solids such as powders, granules or wettable powders, or they may be liquids such as solutions, sprays or emulsifiable concentrates.

For example, powders can be prepared by milling the active compound with solid inert carriers such as curcum, clay, mound, pyrophyllite, and the like.

Granule formulations are usually prepared by injecting the compound dissolved in a suitable solvent onto or into a granulated carrier such as attapulgites or vermiculite, usually with a particle size in the range of about 0.3 to 1.5 cm. It can be prepared by

Wettable powders in which the active compound can be dispersed in water or oil to any required concentration can be prepared by adding a wetting agent to the concentrated powder composition.

In some cases, the active compound is sufficiently soluble in common organic solvents, such as kerosene or xylene, that it can be applied directly as a solution in these solvents.

Solutions of herbicides may often be dispersed as a spray under superatmospheric pressure.

However, preferred liquid herbicidal compositions are emulsifiable concentrates, which consist of an active compound according to the invention and a solvent and an emulsifier as an inert carrier.

Such emulsifiable concentrates can be spread with water and/or oil to any concentration of active compound for application as a spray to the site of weed propagation.

The most commonly used emulsifiers in these concentrates are nonionic or mixed anionic and nonionic surfactants.

Through the use of certain emulsifier systems, inverse emulsions (water in oil) can be prepared for direct use in weed propagation.

Representative herbicidal compositions according to the present invention are shown in the Examples below, in which amounts are percentages by weight.

Example 36 The above ingredients were mixed in a mechanical grinder-blend.
er) and milled until a uniform, free-flowing powder of desired particle size is obtained.

This powder is suitable for direct application to weed-infested areas.

The compounds of this invention may be applied as herbicides in any art-recognized manner.

One way to control weeds is to remove the weeds from an inert carrier,
and a herbicidal composition comprising a compound of the invention as an essential active ingredient in an amount that is herbicidally toxic to the weed.

The concentration of the novel compounds of the present invention in herbicidal compositions will vary widely depending on the form of the formulation and its intended purpose, but generally the herbicidal compositions will have a concentration of about 0.05% by weight.
from about 95 percent of the active compound of the invention.

In preferred embodiments of the invention, the herbicidal composition will contain about 5 to 75 percent active compound by weight.

These compositions may also contain other pesticides such as insecticides, acaricides, fungicides, etc., stabilizers, spreaders, inactivators, adhesives, glues, fertilizers, activators, synergists, etc. It can also contain additives such as.

The compounds of the present invention are also useful in combination with other herbicides and/or defoliants, desiccants, growth inhibitors, etc. in the herbicidal compositions described above.

These other substances may comprise from about 5% to about 95% of the active ingredient in the herbicidal composition.

These other herbicides and/or defoliants, desiccants, etc.
Mixed use with the compounds of the present invention & provides herbicidal compositions that are more effective in controlling eastern weeds, and often produce results that cannot be achieved with separate compositions of the individual herbicides.

Weeds are unnecessary plants that grow in unwanted places, have no economic value, and interfere with the production of cultivated crops, the growth of ornamental plants, or the reproduction of livestock.

Many types of weeds are known, and like pigweed, these weeds can be classified as broad-leaved or grass-like weeds.

There is an economic need to control the growth of such weeds without harming useful plants or livestock.

The compounds of this invention are particularly valuable for weed control because they are toxic to many weed species and groups, while being relatively nontoxic to many beneficial plants.

The exact amount of compound required will depend on many factors, including the difficulty of the particular weed species, weather, soil form, method of application, types of useful plants in the same area, etc.

That is, while application of as little as a gram to 2 ounces of active compound per knee car may be sufficient for good control of minor weed infestations growing under adverse conditions;
Applications of 10 or more pounds of active compound per kneeker may be required for good control of dense growth of hardy perennial weeds that grow under favorable conditions.

The herbicide toxicity of the novel compounds of the present invention can be demonstrated by a number of well-established test methods known in the art, such as pre-emergence and post-emergence testing.

The herbicidal activity of the compounds of the invention was demonstrated by experiments carried out on pre-emergence control of various weeds.

In these experiments, seeds of various weeds were sown in small plastic greenhouse pots filled with dry soil.

At or before 24 hours after sowing, the pots were sprinkled with water until the soil was moist, and the test compound, formulated as an aqueous emulsion in acetone solution containing an emulsifier, was sprinkled onto the soil surface at a defined concentration.

After application, the soil container was placed in a greenhouse with supplemental heating and daily or more frequent watering if necessary.

Plants were maintained under these conditions for 21 days, at which time the condition of the plants and the degree of damage to the plants were rated on a scale of 0 to 10 as follows: 0 - no damage;
1.2-slight impairment, 3.4-moderate impairment, 5.6
- moderately severe disturbance, 7.8.9 - severe disturbance, and 1
〇- It is withering and death.

The efficacy of this compound is demonstrated by the data in Table 1.

The herbicidal activity of the compounds of the invention was also demonstrated by experiments carried out after the emergence of various weeds.

In these experiments, the compound to be tested was formulated as an aqueous emulsifier and sprayed at a prescribed dose onto the leaves of weeds that had reached a predetermined size.

After spraying, the plants were placed in a greenhouse and watered daily or more frequently.

No water was applied to the leaves of the treated plants.

The degree of damage was determined 14 days after treatment and was 0 as previously described.
Evaluation was made on a scale of 1 to 10.

The effectiveness of this compound is shown by the data in Table 2.

Claims (1)

[Scope of Claims] 1. A weed killer comprising an inert carrier and a compound represented by the formula (wherein R4 is lower alkyl or lower alkylamino) in an amount toxic to weeds as an essential active ingredient. agent composition.