CA1060022A - 1-thiadiazolyl-5-acylimidazolidinones - Google Patents

Abstract

Abstract This invention discloses new compounds of the formula wherein R1 is selected from the group consisting of alkyl, cycloalkyl, alkenyl, haloalkyl, alkoxy, alkylthio, alkylsulfonyl and alkylsulfinyl; R2 is selected from the group consisting of alkyl, alkenyl, haloalkyl and wherein R4 and R5 are each selected from the group consisting of hydrogen and alkyl; and R3 is selected from the group con-sisting of alkyl, alkenyl, haloalkyl, alkynyl, alkoxyalkyl, cycloalkyl and

Description

1.060~ZZ
l-THIADIAzoLyL-5-AcyLIMID~zoLIDINoNEs .. ..
Specification This invention relates to new compositions of matter and more specifically relates to new chemical compounds of the formula Il 3 . :
O - C - R
N N
~ f H --CH
R - C C - N
~ / \C I - R2 O (I) .
., ' ..... .
wherein R is selected from the group consisting of alkyl, ~ :

. cycloalkyl, alkenyl, haloalkyl, alkoxy, alkylthio, alkyl- : .

i, sulfonyl and alkylsulfinyl; R2 is selected from the group ~ consisting of alkyl, alkenyl, haloalkyl and . ~ . - . .:
R4 ~ .

- I - C~- CH :
R
wherein R4 and R5 are each selected from the group consisting ;
of hydrogen and alkyl; and R3 is selected from the group con~
t, ~ .
:~ sisting of alkyl, alkenyl, haloalkyl, alkynyl, alkoxyalkyl, :~:
cycloalkyl and --: -wherein X is selected from the group consisting of alkyl, alkoxy, halogen, haloalkyl, alkylthio, nitro and cyano; n i8 an integer from 0 to 3; and m is the integer 0 or 1.

,, . cb/

~0600ZZ
The compoundq of the present invention arc un-expectedly useful as herbicides.
In a preferred embodiment of this invention Rl is selected from the group consisting of lower alkyl, cycloalkyl of from 3 to 7 carbon atoms, lower alkenyl, lower chloroalkyl, lower bromoalkyl, trifluoromethyl, lower alkoxy, lower alkyl-thio, lower alkylsuIfonyl and lower alkylsulfinyl; R2 is select-ed from the group consisting of lower alkyl, lower alkenyl, lower haloalkyl and R4 : ;

- C - C CH

wherein R and R5 are hydrogen or alkyl of up to 3 carbon atoms; and R is selected from the group consisting of lower .
. alkyl, lower alkenyl, lower haloalkyl, lower alkynyl, lower alkoXyalkyl, cycloalkyl of from 3 to 7 carbon atoms and H(5-n) _ ~CN2~m ~

. :
'' ' - -.
wherein X is selected from the group consisting of lower alkyl, lower alkoxy, halogen, lower haloalkyl, nitro, cyano and lower -alkylthio; n is. an integer from 0 to 3; and m is the integer 0 or 1.
The term "lower" as used herein designates a straight or branched carbon chain of up to six carbon atoms. :~
.: ., . The compounds of the present invention can be ~1 30 prepared by reacting a compound of the formula .,:

.~, cb/ - 2 --, .
. : .

.~ , . . . j . .. .

OH
N~ f H --CH2 \ /Ç \C ~ - R

O ~II) wherein Rl and R2 are as heretofore described, with an acid anhydride of the formula R3 - ~ - O - ~ - R3 ~III) wherein R3 is as heretofore described, in the presence of a catalytic amount of _-toluenesulfonic acid. This reaction can be effected by combining the reactants and the catalyst at room temperature in an inert organic reaction medium and ~-: .
then heating the reaction mixture on a steam bath with stirring -for a period of from 1/2 to 4 hours. After this time the .. , . .. ~
reaction mixture can be cooled and the desired product can be ~' recovered by filtration if formed as a precipitate or upon ~1 evaporation of the organic reaction medium if soluble therein.
;` In some $nstances the acid anhydride can be used as a solvent for a compound of formula II, obviating the use of an inert , i solvent as the reaction medium. When lower alkanoic anhydrides ~ J'~
are used, water can be added to the reaction mixture to pre-cipitate the desired product upon completion of the reaction.
' The product can then be purified by conventional means such as f recrystallization and the like. In some instances the fore-~ ~ .
going reaction results in the formation of a mixture of products consisting of the desired compound of this invention and de-~3~ hydrated starting material of the formula ' ' , ' ' .
. f'~
C2~ 3- ~
:, ' , ` ' , :: ~

N ~I CH _ CH

\ S f C N - R2 ll ` ~`:
~IV) wherein Rl and R2 are as described. In these instances the desired product can be isolated by fractional precipitation.
j The compounds of this invention c~ also be prepared `~
~. .
by reacting a compound of formula II with an acid halide of the formula : O

Cl - 11 - R3 ~V ) ~ ` :
wherein R3 is as heretofore described,in the presence of an acid acceptor such as a tertiary amine. This preparational method can be utilized when the desired anhydride of formula 4, III is not available. This reaction can be effected by slowly 7 ~adding the acid chloride of formula V with stirring to a solu- -tion of an about equimolar amount of a compound of formula II ~;
in an inert organic solvent, in the presence of an acid acceptor,.
~; at a temperature of ahout 10 to 30~C. After the addition is completed, the react;on mixture can be heated at a temperature ranging up to the reflux temperature of the mixture to ensure completion of the reaction. The desired product can then be recovered by first filtering the reaction mixture to remove acid àcceptor chloride, followed by stripping off the solvent if the product is soluble therein, or, if formed as a precipi-tate, by filtration and subsequent washing and purification.
~ The compouDds of formula II can be readily prepared .~1 28 by heating a compound of the formula ;~

, 1 ~ . ~ , ' .

~ cb/ - 4 ., ~ ,~ . ..

" 1060022 ~ OCH3 R _ C C _ N ~ C _ N _ C112 _CH
S H O R ol H3 (VI) wherein Rl and R2 are as heretofore described, in a dilute, aqueous, acidic reaction medium for a period of about 10 to about 60 minutes. Temperatures of from about 70C to the reflux temperature of the reaction mixture can be utilized.
The reaction medium can comprise a dilute aqueous inorganic acid such as hydrochloric acid at a concentration of from a~out 0.5 to about 5 percent. Upon completion of the reaction the desired product can be recovered as a precipitate by cool-ing the reaction mixture. This product can be used as such or can be furt~er purified by conventional means such as recrystallization and the like.
The compounds of formula VI can be prepared by reacting a molar amount of an isocyanate dimer of the formula ~ r ¦ S

2 (VII) ~; wherein Rl is as heretofore described, with about two molar J~ amounts of dimethyl acetal of the formula ~, OCH3 H - N - CH - CH

2 1CH 3 (VIII) ! wherein R2 is as heretofore described. This reaction can be , effected by heating a mixture of the isocyanate dimer and the acetal in an inert organic reaction medium such as benzene at :

, 30 the reflux temperature of the reaction mixture. Heating at . reflux can be continued for a period of from about 2 to about 30 minutes to ensure completion of the reaction. A~ter this .. . :
-, cb/ ~

~ . ., . . . . . . . . ~ . .

~0600ZZ
time the desired product can be recov~red upon evaporation of the reaction medium and can be used as such or can be further purified by standard techniques in the art.
The isocyanate dimer of formula VII can be prepared hy reacting a thiadiazole of the formula Rl - C~ ~ - Nl:2 S (IX) wherein Rl is as heretofore described, with phosgene. This reaction-can be effected by adding a slurry or solution of the thiadiazole, in a suitable organic solvent such as ethyl ace-tate, to a saturated solution of phosgene in an organic solvent such as ethyl acetate. The resulting mixture can be stirred at ambient temperatures for a period of from about 4 to about 24 hours. The reaction mixture can then be purged with nitrogen gas to remo~e unreacted phosgene. The desired product can then be recovered by filtration, if formed as a precipitate, or upon evaporation of the organic solvent used if soluble f therein. This product can be used as such or can be further purified as desired.
Exemplary thiadiazoles of formula IX useful for ,~ preparing the compounds of the present invention are 5-methyl-2-amino-1,3,4-thiadiazole, 5-ethyl-2-amino-1,3,4-thiadiazole, S-propyl-2-amino-1,3,4-thiadiazole, 5-t-butyl-2-amino-1,3,4-thiadiazole, 5-allyl-2-amino-1,3,4-thiadiazole, S-pent-3-enyl-f~ 2-amino-1,3,4-thiadiazole, 5-chloromethyl-2-amino-1,3,4-thiadiazole, 5-~-chloroethyl-2-amino-1,3,4-thiadiazole, 5-~
f chloropropyl-2-amino-1,3,4-thiadiazole, 5-trichloromethyl-2-; amino-1,3,4-thiadiazole, 5-trifluoromethyl-2-amino-1,3,4-thiadiazole, 5-methoxy-2-amino-1,3,4-thiadiazole, 5-ethoxy-2- -amino-1,3,4-thiadiazole, S-propoxy-2-amino-1,3,4-thiadiazole, S-butyloxy-2-amino-1,3,4-thiadiazole, 5-hexyloxy-2-amino-1, .

cb/ - - 6 -1060~ZZ

3,4-thiadiazole, 5-mcthylthio-2-amino-1,3,4-thiadiazol~, 5-ethylthio-2-amino-1,3,4-thiadiazole, 5-propylthio-2-amino-1, 3,4-thiadiazole, 5-butylthio-2-amino-1,3,4-thiadiazole, 5-methyl-sulfonyl-2-amino-1,3,4-thiadiazole, 5-ethylsulfonyl-2-amino-1, 3,4-thiadiazole, 5-butylsulfonyl-2-amino-1,3,4-thiadia201e, 5-methylsulfinyl-2-amino-1,3,4-thiadiazole, 5-ethylsulfinyl-2-amino-1,3,4-thiadiazole, 5-propylsulfinyl-2-amino-1,3,4-thia-diazole, 5-butylsulfinyl-2-amino-1,3,4-thiadiazole and the like.
Exemplary suitable acetals of formula VIII for pre-paring the compounds of this invention are the dimethyl acetal of 2-methylaminoacetaldehyde, the dimethyl acetal of 2-ethyl-aminoacetaldehyde, the dimethyl acetal of 2-propylamino-acetaldehyde, the dimethyl acetal of 2-butylaminoacetaldehyde, the dimethyl acetal of 2-pentylaminoacetaldehyde and the di-methyl acetal of 2-hexylaminoacetaldehyde.
Exemplary suitable acid anhydrides of formula III
are acetic anhydride, propionic anhydride, butanoic anhydride, pentanoic anhydride, hexanoic anhydride, acrylic anhydride, butenoic anhydride, pentenoic anhydride, chloroacetic anhydride, , bromoacetic anhydride, ~-chlorobutanoic anhydride, cyclohexyl-, carboxylic anhydride, benzoic anhydride, toluic anhydride, ~-~

4-chlorobenzoic anhydride, 3-bromobenzoic anhydride, 4-fluoro-benzoic anhydride, 4-methoxybenzoic anhydride, 4-ethoxybenzoic i .: , anhydride, 4-chloromethylbenzoic anhydride, 4-trifluoromethyl- -benzoic anhydride, 3,4,5-trichlorobenzoic anhydride, 3-methyl-thiobenzoic anhydride, 3-ethylthiobenzoic anhydride, 4-butyl-thiobenzoic anhydride, phenylacetic anhydride, 4-methylphenyl-` acetic anhydride, propynoic anhydride, butynoic anhydride, .
methoxyacetic anhydride, ~-methoxypropionic anhydride, ~-ethoxybutanoic anhydride and the like.

Exemplary suitable acid chlorides of formula V

cb/ _ 7 .
., - . .. ..... .

1~60022 useful for preparing the compounds of the present invention are the acid halides of the samc acids as set forth above in the examples of acid anhydrides.
The manner in which the compounds of the present - invention can be prepared is more specifically illustrated in the following examples.
Example 1 Preparation of 5-t-Butyl-1,3,4-thiadiazol-2-yl Isocyanate Dimer A saturated solution of phosgene in ethyl acetate ~100 ml) was charged into a glass reaction vessel equipped with a mechanical stirrer. A slurry of 5-t-butyl-2-amino-1, 3,4-thiadiazole ~10 grams~ in ethyl acetate (300 ml) was added to the reaction vessel and the resulting mixture was stirred ~or a period of about 16 hours resulting in the formation of a precipitate. The reaction mixture was then purged with nitrogen gas to remove unreacted phosgene. The purged mix-ture was then filtered to recover the desiréd product 5-t-hutyl-1,3,4-thiadiazol-2-yl isocyanate as a solid having a melting point of 261 to 263C.
Example 2 ' Preparation of the Dimethyl Acetal of 2-~1-Methyl-3-~5-~-butyl-1,3-,4-thiadiazol-2-yl)ureido]acetaldehyde A mixture of 5-t-butyl-1,3,4-thiadiazol-2-yl iso-- cyanate dimer (6 grams), the dimethyl acetal of 2-methylamino-acetaldehyde ~3.9 grams) and benzene (50 ml) was charged into a glass reaction flask equipped with a mechanicf~ stirrer and reflux condenser. The reaction mixture was heated at reflux, ~,~ with stirring for a period of about 5 minutes. After this -~ ~time the reaction mixture was stripped of benzene to yield an ` oil which solidified upon standing. The resulting solid was then recrystallized from pentane to yield the desired product the dimethyl acetal of 2-El-methyl-3-(5-t-butyl-1,3,4-thiadiazol-2-yl)ureido]-acetaldehyde having a melting point o~ 80-82C.
cb/ - 8 - -11~600Z2 Example 3 Preparation of 1-(5-t-Butyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-hydroxy-1,3-imidazolidin-2-one The dimethyl acetal of 2-[1-methyl-3-~5 t-butyl-l, 3,4~thiadiazol-2-yl)ureido]acetaldehyde (16 grams), concentrated hydrochloric acid ~10 ml) and water (500 ml) were charged into a glass reaction vessel equipped with a mechanical stirrer, thermometer and reflux conden~er. The reaction mixture was heated at reflux for a period of about 15 minutes. The reaction mixture was filtered while hot and the filtrate was then cooled, resulting in the formation of a precipitate. The precipitate was recovered by filtration, dried and was recrystallized from a benzene-hexane mixture to yield the desired product 1-(5-t-butyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-hydroxy-1,3-imidazolidin-2-one having a melting point of 133 to 134C.
Example 4 Preparation of 1-~5-t-Butyl-1,3,4-thiadiazol-~ - 2-yl)-3-methyl-5-acetyloxy-1,3-imidazolidin-2-one j l-~5-_-Butyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-~ 20 hydroxy-1,3-imidazolidin-2-one ~70 gramsj, acetic anhydride -~ (56 grams) and a catalytic amount of toluenesulfonic acid were charged into a glass reactionvessel equipped with a mechanical stirrer and thermometer. The reaction mixture was heated on a steam bath with continued stirring for a period of about 2 hours. After this time water ~500 ml) was added to the reaction mixture resulting in the formation of a preci-i1 pitate. The precipitate was recovered by filtration and was dried in an oven at 60C. The dried product was then re-~, ~ crystallized from methanol to yield the desired product 1-(5-, 30 t-butyl-1,3,4-thiadiazol-2-yl~-3-methyl-5-acetyloxy-1,3-imidazolidin-2-oné having a melting point of 141C.
,: :

cb/ ~ 9 ~

, . :
, ~:

1060l);~
Example 5 Preparation of 5-Trifluoromethyl-1,3,4-thiadiazol-2-yl Isocyanate Dimer A saturated solution of phosgene in ethyl acetate ll~0 ml) was charged into a glass reaction vessel equipped with a mechanical stirrer. A slurry of 5-trifluoromethyl-2-amino-1,3,4-thiadiazole (45 grams) in ethyl acetate ~300 ml) was added to the reaction vessel and the resulting mixture was stirred for a period of about 16 hours resulting in the formation of a precipitate. The reaction mixture was then pur~ed with nitrogen gas to remove unreacted phosgene. The pur~ed mixture was filtered to recover 48 grams of a white solid. This solid was recrystallized from dimethyl formamide to yield the desired product 5-trif ~ romethyl-1,3,4-thiadiazol--I 2-yl isocyanate dimer.
Example 6 Preparation of the Dimethyl Acetal of 2-[1-Methyl-3-(5-trifluoromethyl-1,3,4-thiadiazol-2-yl)ureido]acetaldehyde -A mixture of 5-trifluoromethyl-1,3,4-thiadiazol-2-yl -~ 20 isocyanate dimer ~9.5 grams), the dimethyl acetal of 2-methyl-aminoacetaldehyde ~5.8 grams) and benzene ~60 ml) are char~ed into a glass reaction vessel equipped with a mechanical stirrer and reflux condenser. The reaction mixture is heated at reflux for a period of about 15 minutes. After this time the mixture ;~
is stripped of benzene under reduced pressure to yield a solid -product as the residue. This product is recrystallized from ~ heptane to yield the desired product the dimethyl acetal of -~ 2~ methyl-3-~5-trifluoromethyl-1,3,4-thiadiazol-2-yl)ureido)-I acetaldehyde having a melting point of 101 to 102~C.
`!
Example 7 ` Pxeparation of 1-~5-Trifluoromethyl-1,3,4-thiadiazol- -2-vl3-3-methYl-5-hvdroxY-1,3-imidazolidin-2-one The dimethyl acetal of 2-[1-methyl-3-(5-trifluoro-meth~l-1,3,4-thiadiazoI-2-yl)ureido3acetaldehyde ~15 grams), ."~ .
cb/ - 10 -4 ~ !

~06002Z
water ~400 ml) and hydrochloric acid t4 ml) were charged into a glass reaction vessel equipped with a mechanical stirrer, thermometer and reflux condenser. The reaction mixture was heated at reflux for a period of about 15 minutes.
The reaction mixture was then filtered while hot and the fil-trate was cooled resulting in the formation of a precipitate.
The precipitate was recovered by filtration, was dried and was recrystallized from an ethyl acetate-hexane mixture to yield the desired product 1-(5-trifluoromethyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-hydroxy-1,3-imidazolidin-2-one having a melt-ing point of 136 to 138C.
Example 8 Preparation of 1-~5-Trifluoromethyl-1,3,4-thiadiazol-2--y1)-3-methyl-5-acetyloxy-1,3-imidazolidin-2-one 1-(5-Trifluoromethyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-hydroxy-1,3-imidazolidin-2-one (0.05 mole), acetic anhydride (6 ml), acetic acid (20 ml) and toluenesulfonic acid ~0.1 gram) are charged into a glass reaction vessel equipped -with a mechanical stirrer and thermometer. The reaction mix-ture is stirred at room temperature for a period of about 24 hours. After this time water ~200 ml) is added to the reaction mixture. The resulting mixture is then extracted with ether.
.
The ether extract is washed with aqueous sodium carbonate and is dried over anhydrous magnesium sulfate. The dried solution is then filtered and stripped of solvent under reduced pressure to yield a solid residue. This solid residue is recrystallized from a water-methanol mixture to yield the desired product 1-(5-trifluoromethyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-acetyloxy-1,3-imidazolidin-2-one as a crystalline ..
1 30 solid having a melting point o 72 to 74C.
;i` Additional compounds of the present invention which i~-, can be prepared by the procedures of the foregoing examples are l-t5-hexyl-1,3,4-thiadiazol-2-yl)-3-ethyl-5-acetyloxy-1,3-.. . .
cb/ - 11 -, : - :

` 106002Z
imidazolidin-2-one, 1-~5-t-butyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-propionyloxy-1,3-imidazolidin-2-one, 1-(5-trifluoro-methyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-butanoyloxy-1,3-imidazolidin-2-one, 1-(5-pentyl-1,3,4-thiadiazol-2-yl)-3-ethyl-

5-acryloyloxy-1,3-imidazolidin-2-one, 1 (5-_-butyl-1,3,4-thiadiazol-2-yl)-3-propyl-5-chloroacetyloxy-1 ! 3-imidazolidin-2-one, 1-(5-t-butyl-1,3,4-thiadiazol-2-yl)-3-allyl-5-cyc].o-hexylcarbonyloxy-1,3-imidazolidin-2-one, 1-(5-trifluoromethyl-1, 3,4-thiadiazol-2-yl)-3-chloromethyl-5-acetyloxy-1,3-imidazo-lidin-2-one, 1-(5-trifluoromethyl-1,3,4-thiadiazol-2-yl)-3- ~ :
propargyl-5-(3-methylbenzoyloxy)-1,3-imidazolidin-2-one, 1-(5-tri~
fluoromethyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-(4-chlorobenzoyl-oxy)-1,3-imidazclidin-2-one, 1-(5-_-butyl-1,3,~-thiadiazol-2-yl)-3-(1,1-dimethylprop-2-ynyl)-5-(4-methoxybenzoyloxy)-1,3-imidazo-lidin-2-one, 1-(5-t-butyl-1,3,4-thiadiazol-2-yl)-3-methyl-5- ~ :
(4-trifluoromethylbenzoyloxy)-1,3-imidazolidin-2-one, 1-(5- : -trifluoromethyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-(4-methyl- ~ -thiobenzoyloxy)-1,3-imidazolidin-2-one, 1-(5-trifluoromethyl-1,3,4-thiadiazol-2-yl)-3-ethyl-5-acetyloxy-1,3-imidazolidin-2-one, 1-~5-trifluoromethyl-1,3,4-thiadiazol-2-yl)-3-ethyl-5-- methoxyacetyloxy-1,3-imidazolidin-2-one, 1-(5-t-butyl-1,3,4-thiadiazol-2-yl).-3-methyl-5-(3-methylphenyl-acetyloxy-1,3-imidazolidin-2-one, 1-(5-trifluoromethyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-propynoyloxy-1,3-imidazolidin-2-one, 1-(5-trifluoromethyl-1,3,4-thiadiazol-2-yl)-3-propyl-5-(3-cyano- .~:
benzoyloxy)--1,3-imidazolidin-2-one, 1-(5-sec-butyl-1,3,4-thiadiazol-2-yll-3-propyl-5-(4-nitrobenzoyloxy)-1,3-imidazo-lidin-2-one, 1-~5-t-butyl-1,3,4-thiadiazol-2-yl~-3-propyl-5-~enzoyloxy-1,3-imidazolidin-2-one, 1-(5-trifluoromethyl-1, 3,4-thiadiazol-2-yl)-3-propyl-S-benzoyloxy-1,3-imidazolidin-one, 1-(5-ethyl-1,3,4-thiadiazol-2-yl)-3-ethyl-S-acetyloxy-l, :

3-imidazolidin-2-one, 1-(5-propyl-1,3,4-thiadiazol-2-yl)-3-propyl-S-propanoyloxy-1,3-imidazolidin-2-one, 1-(5-butyl-1,3, 4-thiadiazol-2-yl)-3-butyl-5-butanoyloxy-1,3-imidazolidin-2-cb/ - 12 -.. . ... . . : :. .. .

1C~60022 one, l-(5-pentyl-1,3,4-thiadiazol-2-yl)-3-pentyl-S-pentanoyl-oxy-1,3-imidazolidin-2-one, 1-(5-hexyl-1,3,4-thiadiazol-2-yl)-3-hexyl-5-hexanoyloxy-1,3-imidazolidin-2-one, 1-(5-cycloheptyl-1,3,4-thiadiazol-2-yl)-3-but-3-enyl-5-pent-4-enoyloxy-1,3-imidazolidin-2-one, 1-(5-but-2-enyl-1,3,4-thiadiazol-2-yl)-3-pent-4-enyl-5-hex-4-enoyloxy-1,3-imidazolidin-2-one, 1-(5- :' pent-3-enyl-1,3,4-thiadiazol-2-yl)-3-hex-5-enyl-5-~-chloro- ;:
acetyloxy-1,3-imidazolidin-2-one, 1-(5-hex-4-enyl-1,3,4-thia-diazol-2-yl)-3-~-chloroethyl-5-~-bromobutanoyloxy-1,3-imi-dazolidin-2-one, 1-(.5-~-chloroethyl-1,3,4-thiadiazol-2-yl)-3-iodomethyl-5-~-chloropentanoyloxy-1,3-imidazolidin-2-one, 5-~-chloropropyl-1,3,4-thiadiazol-2-yl)-3-trifluoromethyl-5-~-chlorohexanoyloxy-1,3-imidazolidin-2-one, 1-(5-bromomethyl-1,3,4-thiadiazol-2-yl)-3-~-chloroethyl-5-~-iodoacetyloxy-1,3-imidazolidin-2-one, 1-~5-~-bromoethyl-1,3,4-thiadiazol-2-yl)-3-~-bromopropyl-5-cyclopropylcarbonyloxy-1,3-imidazolidin-2~
one, 1-(5-trichloromethyl-1,3,4-thiadiazol-2-yl)-3-~-bromohexyl- ; -' 5-cyclobutylcarbonyloxy-1,3-imidazolidin-2-one, 1-(5-~-chloro-hexyl-1,3,4-thiadiazol-2-yl)-3-~-chlorohexyl-5-cyclopentyl-carbonyloxy-1,3-imidazolidin-2-one, 1-~5-ethoxy-1,3,4-thia-diazol-2-yl)-3-(1,1-diethylprop-2-ynyl)-5-cycloheptylcarbonyl-oxy-1,3-imidazolidin-2-one, 1-(5-butoxy-1,3,4-thiadiazol-2-yl)-3-(1,1-dipropylprop-2-ynyl)-5-~2-ethylbenzoyloxy)-1,3-,-imidazo-lidin-2-one, 1-(5-hexyloxy-1,3,4-thiadiazol..2-yl)-3-methyl-5-(3-propylbenzoyloxy~.-1,3-imidazolidin-2-one, 1-(5-ethylthio-1, 3,4-thiadiazol-2-yl~-3-methyl-5-~4-hexylbenzoyloxy)-1,3-imidazo-lidin-2-one, 1-~5-propylthio-1,3,4'-thiadiazol-2-yl)-3-methyl-5-~.3-ethoxybenzoyloxy)-1,3-imidazolidin-2-one, 1-(5-pentylthio-1,3,4-thiadiazol-2-yl~-3-methyl-5-(4 butoxybenzoyloxy)-1,3-'imidazolidin-2-one, 1-(5-hexylthio-1,3,4-thiadiazol-2-yl)-3-methyl-S-t4-hexyloxybenzoyloxy)-1,3-imidazolidin-2-one, 1-(5-ethylsulfonyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-~4-bromo-.

cb/ - 13 -.,. , . ,i .. . , benzoyloxy)-1,3-imidazolidin-2-one, 1-(5-propylsulfonyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-(4-iodobenzoyloxy)-1,3-imidazo-lidin-2-one, 1-(5-pentylsulfonyl-1,3,4-thiadiazol-2-yl)-3- ~
methyl-5-(4-flu~robenzoyloxy)-1,3-imidazolidin-2-one, 1-(5- - :
hexylsul~onyl-1,3,4-thiadiazol-2-yl)-3-methyl-S-(2,4-dichloro~
benzoyloxy)-1,3-imidazolidin-2-one, 1-(5-ethylsulfinyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-(2,4,6-trichlorobenzoyloxy)-1,3-imidazolidin-2-one, 1-(5-propylsulfinyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-(3,4-dibromobenzoyloxy)-1,3-imidazolidin-?-one, 1-~5-~utylsulfinyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-(4-tri-fluoromethylbenzoyloxy~-1,3-imidazolidin-2-one, 1-(5-hexylsulfinyl- :
1,3,4-thiadiazol-2-yl)-3-methyl-5-(4-chloromethylbenzoyloxy)-1,3-imidazolidin-2-one, 1-(5-isopropyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-alkylthiobenzoyloxy-1,3-imidazolidin-2-one, 1-t5~
isopropyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-propylthiobenzoyl-oxy-1,3-imidazolidin-2-one, 1-~5-isopropyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-pentylthiobenzoyloxy-1~3-imidazolidin-2-one~
1-~5-isopropyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-hexylthio-benzoyloxy-1,3-imidazolidin-2-one, 1-(5-methyl-1,3,4-thia- . :
diazol-2-yl)-3-methyl-5-butynoyloxy-1,3-imidazolidin-2-one, :-1-(5-methyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-pent-4-ynyloxy-1,3-imidazolidin--2-one, 1-~5-methyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-hex-4-ynyloxy-1,3-imidazolidin-2-one, 1-(5-methyl-1, 3,4-thiadiazol-2-yl)-3-methyl-5-~-methoxypropionyloxy-1,3-midazolidin-2-one, 1-(5-methyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-~-methoxybutanoyloxy-1,3-imidazolidin-2-one, 1-(5- -methyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-3-methoxypentanoyloxy-1,3-imidazolidin-2-one, 1-(5-methyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-~-ethoxypropionyloxy-1,3-imidazolidin-2-one, 1-t5-methyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-propoxyacetyloxy-1,3-imidazolidin-2-one, 1-(5-methyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-butoxyacetyloxy-1,3-imidazolidin-2-one, 1-~5- methyl-1, 3,4-thiadiazol-2-yl)-3-methyl-5-hexyloxyacetyloxy-1,3-imidazo-lidin-2-one, 1-~5-methyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-- 14 - :

~6002~
(3,4-dichlorophenylacetyloxy)-1,3-imidazolidin-2-one, 1-(5-methyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-(4-trifluoromethyl-phenylacetyloxy)-1,3-imidazolidin-2-one, 1-(5-methyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-~2-methyl-4-chlorophenylacetyloxy)-1,3-imidazolidin-2-one, 1-(5-methyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-(-3-methylthiophenylacetyloxy)-1,3-imidazolidin-2-one, 1- ~-methyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-(2-methoxyphenyl-acetyloxy)-1,3-imidazolidin-2-one and the like.
For practical use as herbicides the compounds of lQ this invention are generally incorporated into herbicidal com-positions which comprise an inert carrier and a herbicidally toxic amount of such a compound. Such herbicidal compositions, which can also be called formulations, enable the active com-pound to be applied conveniently to the site of the weed infestation in any desired quantity. These compositions can be solids such as dusts, granules, or wettable powders;
or they can be liquids such as solutions, aerosols, or emulsi-fiable concentrates.
For example, dusts can be prepared by grinding and blending the active compound with a solid inert carrier such as the talcs, clays, silicas, pyrophyllite, and the like.
Granular formulations can be prepared by impregnating the com-pound, usually dissolved in a suitable solvent, onto and into granulated carriers such as the attapulgites or the vermi-culites, usually of a particle size range of from about 0.3 to 1.5 mm. Wettable powders, which can be dispersed in ~ater or oil to any desired concentration of the active com-pound, can be prepared by incorporating wett~ing agents into concentrated dust compositions.
j 30 In some cases the active compounds are sufficiently soluble in common organic solvents such as kerosene or xylene so that they can be used directly as solutions in these solvents.

~b/ - 15 -1~600;~2 Frequently, solutions of herbicides can be dispersed under superatmospheric pressure as aerosols. However, preferred liquid herbicidal compositions are emulsifiable concentrates, which comprise an active compound according to this invention and as the inert carrier, a solvent and an emulsifier. Such emulsifiable concentrates can be extended with water and/or oil to any desired concentration of active compound for appli-cation as sprays to the site of the weed infestation. The emulsifiers most commonly used in these concentrates are nonionic or mixtures of nonionic wlth anionic surface-active agents. With the use of some emulsifier systems an inverted emulsion (water in oil) can be prepared for direct application , to weed infestations.
A typical herbicidal composition according to this invention is illustrated by the following example, in which the quantities are in parts by weight.

~ . .... .
, EXAMPLE 9 Preparation of a Dust , Product of Example 4 10 1 20 Powdered Talc go -, The above ingredients are mixed in a mechanical grinder-blender and are ground until a homogeneous, free-flowing dust of the desired particle size is obtained.
~j ThiS dust is suitable for direct application to the site of the weed infestation.
The compounds of this invention can be applied as herbicides in any manner recognized by the art. One method ~i for the control of weeds comprises contacting the locus of said weeds with a herbicidal composition comprising an inert carrier and as an essential active ingredient, in a quantity which is herbicidally toxic to said weeds, a compound of the . :, .
~ cb/ ~ - 16 -'; . , ."~ ~,':

present invention. The concentration of the new compoun~ of this invention in the herbicidal compositions will vary greatly with the type of formulation and the purpose for which it is designed, but generally the herbicidal compositions will com-prise from about 0.05 to about g5 percent by weight of the active compounds of this invention. In a preferred embodiment of this invention, the herbicidal compositions will comprise from about 5 to about 75 percent by weight of the active com- -pound. The compositions can also comprise such additional substances as other pesticides, such as insecticides, nema-tocides, fungicides, and the like; stabilizers, spreaders, deactivators, adhesives, stickers, fertIlizers, activators, synergists, and the like.
The compounds of the present invention are also useful when combined with other herbicid~s and/or defoliants, dessicants, growth inhibitors, and the like in the herbicidal compositions heretofore described. These other materials can comprise from about 5% to about 95% of the active ingredients ~n the herbicidal compositions. Use of combinations of these other herbicides and/or defoliants, dessicants, etc. with the compounds of the present invention provide herbicidal composi-tions which are more effective in controlling weeds and often provide results unattainable with separate compositions of the individual herbicides.
Weeds are undesirable plants growing where they are ~-not wanted, having no economic value, and interfering with ~he production of cultivated crops, with the growing of orna-mental plants, or with the welfare of livestock. Many types of weeds are known, including annuals such as pigweed, lambs-3~ quarters, foxtail, crabgrass, wild mustard, field pennycress, ryegrass, goose grass, chickweed, wild oats, velvetleaf, purs-lane, barnyardgrass, smartweed, knotweed, cocklebur, wild -cb/ - 17 -, 0600zz buckwheat, kochia, medic, corn cockle, ragweed, sowthistle, coffeeweed, croton, cuphea, dodder, fumitory, groundsel, hemp nettle, knawel, spurge, spurry, emex, jungle rice, pondweed, dog fennel, carpetweed, moringglory, bedstraw, ducksalad, naiad, cheatgrass, fall panicum, jimsonweed, witchgrass, : switchgrass, watergrass, teaweed, wild turnip and sprangle-top; biennials such as wild carrot, matricaria, wild barley, campion, chamomile, burdock, mullein, roundleaved mallow, bull thistle, houndstongue, moth mullein and purple star thistle; -or perennials such as white cockle, perennial ryegrass, quack-grass,Johns~ongrass, Canada thistle, hedge bindweed, Bermuda ...... .
grass, sheep sorrel, curly dock, nutgrass, field chickweed, dandelion, campanula, field bindweed, Russian knapweed, mesquite, toad~lax, yarrow, aster, gromwell, horsetail, , . . . .
ironweed, sesbania, bulrush, cattail, winter-cress, horse-.. nettle, nutsedge, milkweed and sicklepod.
. Similarly, such weeds can be classified as broad-.leaf or grassy weeds. It is economically desirable to control the growth of such weeds without damaging beneficial plants or livestock.
. The new compounds of this invention are particularly .~ valuable for weed control because they are toxic to many speci~s .
and groups of weeds while they are relatively non-toxic to ...
many beneficial plants. The exact amount of compound required will depend on a variety of factors, including the hardiness .
of the particular weed species, weather, type of soil, method ;
of application, the kind of beneficial plants in the same area and the like. Thus, while the application of up to only . ~ .
about one or-two ounces of active compound per acre may be . 30 sufficient for good control of a light infestation of weeds ~:. :

.l growing under adverse conditions, the application of ten ..

- pounds or more of an active compound per acre may be required . . ~.

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~0600ZZ

for good control o a dense infestation of hardy perennial weeds growing under favorable conditions.
The herbicidal toxicity of the new compounds of this invention can be illustrated by many of the established testing techniques known to the art, such as pre- and post-emergence testing.
The her~icidal activity of the compounds of this invention was demonstrated by experiments carried out for the pre-emergence control of a variety of weeds. In these experi-ments small plastic greenhouse pots filled with dry soil were seeded with the various weed seeds. Twenty-four hours or less after seeding the pots were sprayed with water until the soil was wet and the test compound formulated as an aqueous emulsion of an acetone solution containing emulsifiers was sprayed at the indicated concentrations on the surface of the soil.
After spraying, tne soil containers were placed in the greenhouse and provided with supplementary heat as required and daily or more frequent watering. The plants were maintained under these conditions for a period of from 15 to 21 days, at -which time the condition of the plants and the degree of injury to the plants was rated on a scale of from 0 to 10, as follows:
0 = no injury, 1,2 = slight injury, 3,4 = moderate injury, -5,6 = moderately severe injury, 7,8,9 = severe injury and lO = death. The effectiveness of the compounds is demonstrated by the following data:

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`` ~0600ZZ
T~BLE I
INJURY RATING
Product of Example 4 Concentration ~Pounds per Acre) .. .... .. .
Weed Species 4 1 1/4 Yellow Nutsedge 10 8 5 Wild Oats 10 10 9 Jimsonweed 9 9 8 Velvetleaf 10 10 9 ~ Johnsongrass 10 10 10 "' Pi~weed 10 10 10 Mustard 10 10 10 Yellow Foxtail 10 10 10 Barnyardgrass 10 10 10 ,l Crabgrass 10 10 10 ' ~ Cheatgrass 10 10 lO
i~ Morningglory 10 10 lO
. ';: .
The herbicidal activity of the compounds of this ~ -, 20 in~ention was also demonstrated by experiments carried out .
7~ for the post-emergence control of a variety of weeds. In these experiments the compound to be tested was formuiated a~ an aqueous emulsion and sprayed at the indicated dosage ,.
on the foliage of the weeds that had attained a prescribed ize. After spraying, the plants were placed in a green-houSe and watered daily or more frequently. Water was not ~ -~ applied to the foliage of the trea-ted plants. The severity ,i of the injury was determined 10 to 15 days after treatment and was rated on the scale of from 0 to 10 heretofore described. ~-~
_ .. . ~ . . . . . .
~1 ~ 30 The effectiveness of the compounds is demonstrated by the -:7~ ~ following data:
', .. .
.~, . .

~060022 TABLE II
INJURY RATING
Product of Example 4 Concentration (Pounds per Acre) Weed Species 4 1 1 Yellow Nutsedge 10 10 4 Wild Oats 10 10 10 Jimsonweed 10 10 10 Pigweed 10 10 10 Johnsongrass 10 10 10 'i, Bindweed 10 9 10 Mustard 10 10 10 Yellow Foxtail 10 10 10 Barnyardgrass 10 10 10 Crabgrass 10 10 10 Mornin~glory 10 10 10 ''~, '' ' ' :'t ' ... .
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.

Claims (8)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. The process for preparing a compound of the formula wherein R1 is selected from the group consisting of alkyl, cycloalkyl, alkenyl, haloalkyl, alkoxy, alkylthio, alkyl-sulfonyl and alkylsulfinyl; R2 is selected from the group consisting of alkyl, alkenyl, haloalkyl and wherein R4 and R5 are each selected from the group consisting of hydrogen and alkyl; and R3 is selected from the group con-sisting of alkyl, alkenyl, haloalkyl, alkynyl, alkoxyalkyl, cycloalkyl and wherein X is selected from the group consisting of alkyl, alkoxy, halogen, haloalkyl, alkylthio, nitro and cyano;
n is an integer from 0 to 3; and m is the integer 0 or 1;
which comprises reacting a compound of the formula wherein R1 and R2 are as heretofore described, with an acid anhydride of the formula or with an acid halide of the formula wherein R3 is as heretofore described.

2. The process of claim 1 wherein the first-identified reactant is reacted with the described acid anhydride in the presence of a catalytic amount of p-toluene-sulfonic acid.

3. The process of claim 1 wherein the first-identified reactant is reacted with the described acid halide in the presence of an acid acceptor.

4. The process of claim 3 wherein the acid acceptor is a tertiary amine.

5. A compound selected from the group consisting of:
(a) 1-(5-t-butyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-acetyloxy-1,3-imidazolidin-2-one;
(b) 1-(5-trifluoromethyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-acetyloxy-1,3-imidazolidin-2-one.

6. 1-(5-t-Butyl-1,1-(5-t-butyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-acetyloxy-1,3-imidazolidin-2-one.

7. 1-(5-Trifluoromethyl-1-(5-trifluoromethyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-acetyloxy-1,3-imidazollidin-2-one.

8. A method of controlling weeds which comprises contacting said weeds with a herbicidal composition comprising an inert carrier and, as an essential active ingredient, in a quantity toxic to weeds, a compound of claim 5.