CA1120747A - Herbicidal agents - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
The compounds [(3-amino-3-carboxy)-propyl-1]-methylphosphinic acid and its hydrochloride salt are useful for combatting a great variety of mono and dicotyledonous weeds.

Description

Our Patent Appl;cation Serial No. 278,456 relates to novel compounds having herbicidal utility. Thus, the invention provides compounds o-f the formula ,0, R,5 R3 - C - C ~ ~CH2)2 \ .~HY)m ~I) in which Rl represents methyl which is unsubstituted or is halogenated 1 to 3 times, R2 represents -OH or -OM ~wherein M is the equivalent of an inorganic or organic base), R3 represents a) -OH or -OM (wherein M is the equivalent of an inorganic or organic base), b) ~Cl-C12)-alkoxy which may be substituted by OH, c~ amino, (Cl-C4)-alkylamino, ~C7-C10)-phenalkylamino, hydrazino or anilino, R4 represents hydrogen, ~Cl-C4)-acyl, halogen-~Cl-C4)-acyl, benzoyl or radicals of the formula -C ~O)NR6R7 R5 represents hydrogen or ~Cl-C4)-alkyl, R6 represents hydrogen or ~Cl-C4)-alkyl, R7 represents hydrogen, ~Cl-C4)-alkyl or phenyl, which is unsubstituted or is substituted in the phenyl ring by ~Cl-C4)-alkyl, F, Cl, Br, N02, CC13 or C~3, Y represents the anion of an inorganic or organic acid having a dissocia- -~
tion constant > 10 3, m represents 0, 1/2 or 1, with the proviso that when R
represents a methyl group, R4 and R5 both represent hydrogen and R2 and R3 both represent -OH, m is not zero and Y is not chlorine.
The present application which is divided out of Application Serial No. 278,456, relates to a method for combatting undesired plant growth which comprises applying to the plant or to the habitat of the plant a herbicidally effective amount of [~3-amino-3-carboxy)-propyl-1]-methylphosphinic acid or [~3-amino-3-carboxy)-propyl-1[-methylphosphinic acid hydrochloride.

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iJ~'7 The compounds used in the invention may be prepared, for example, by nucleophilic substitution of halogenoethylphosphinic acid esters with acetamin-omalonic acid esters in the presence of molar amounts of a strong base, and subsequent saponification and decarboxylat:ion of the resulting intermediate product ~Japanese Application No. 7,391,019):

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~ P(CH2)2Br + NaC~COOC2H5)2 -NaBr / P(C~12)21( 2 5)2 C2H50 NHCCH3 C2H50 NHC,CH3 CH3 ,0, HCl ~ \ P~CH2)2CH-COOH HCl HO N~12 3-amino-3-carboxypropylphosphinic acid may also be prepared by adding acetyl-aminomalonic acid esters to vinylphosphinic acid esters in the presence of catalytic amounts of a strong base, and subsequent saponification of the adduct:

PCH=CH2 ~ HC~COOC2H5)2 NaOC2H5 O

3 " 3 \ "
/ PcH2cH2c(cooc2H5)2 HCl > PCH2CH2CH-COOH . HCl ClCH2CH20 " 3 HO NH2 , . . .

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'7 A further method considered for the preparation of the compounds of the formula I is, for example, the Streckersche synthesis:

CH3 0 0 CH3 o H
\ ~ ~ 1) CN-, NH3 \ ~

/ ( 2)2CH 2) }ICl ~ P~CH2)2C-COOH
C2H50 HO N~2 . HCl The compounds used in the method of the invention exhibit a very good and very wide-ranging herbicidal action against numerous monocotyledonous and dicotyledonous weeds of many botanical families of one year and several years old. This property of action against a wide variety of weeds, which usually occur in association with each other, renders possible the use of the compounds according to the invention for combatting undesired plant growth, ~;
for example at the edges of paths, in industrial sites or railway sites, or for combatting aquatic plants. The compounds may also be used ~4~

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with advantage in annual and perennial agricultural crops, espe-cially if the manner of application and/or the age o the crop plants ensures that the crop plants or their sensitive parts do not come into contact with the herbicidal substances and are thus not damaged. Examples of these are plantations, tree plantations, vine crops etc.
Since application in commercial crops before emergence does not cause or causes only slight damage to the crop plants, these compounds can be used against weeds before emergence o the seed or before sowing or after harvesting.
They may, however, also be used against plant growth, hindering harvesting, of the commercial plant itsel ~cotton, potatoes).
The agents according to the invention contain the active substances in an amount of 2-95%. Since the active substances are partially water-soluble, they may advantageously be used in the form of aqueous solutions. Otherwise, it is possible to use as emulsifiable concentrates, wettable powders and sprayable solutions in the customary forms of preparation if they are not themselves water-soluble. Wet-table powders are preparations uniformly dispersible in water that contain in addition to the active substance , apart from a diluent or inert substance, wetting agents, for example, polyoxethylated alkyl phenols, polyoxethylated oleyl or stearyl amines, alkyl or alkylphenyl ,, , sulp~onates and dispersin~ agents, for example, a sodium ~alt o~ ligninsulfonic acid, a sodium salt of 2,2'-dinaphthylmeth~qe-6,6 7 -disul~onic acid, a sodium salt of dibutylnapht.~lenesul~onic acid or also a sodium salt o oleylmethyltaurine acid.
Emulsifiable concentrates are obtained by dissol~ing the act-ve substance in an organic ~ol~ent, for e~mple butanol, cyclohexanone, x~lene or also aromatic substances of hi~her boiling points.
To achieve good suspensions or emulsions in water, wettir~
agents fro3 the above-mentioned series are furthermore added.
Sprayable 301utions, as handled widely in spray packs, contain ths active subst~nce dissolved in an organic solvent, and ~he propellant used is, ~or example, a mixture of fluoro- ;
chlorohydrocarbon~, In herbicidal agents, the concentrations of the acti~e ~ubsta~ces in the commercially cus~omary formulations ma~ be different. In wettable powders the concentration o~ acti~e substance varies ~or e~ample, between appro~imately 10% a~d 80~p, the remainder consisti~g oi the above-mentioned formula- ;
tion additi~es. In emulsiîiable concentratas the coneentration of acti~e substa~ce is approximately 10 to 60~o.
~or zpplication, the commercially customary concentrates are, if necessary~ diluted in the usual manner, for e~ample b~
means of water in the case of wettable powders and emulsifiable ~ `
concentrates. Sprayable 601utions are not diluted with ~ur-ther inert substance6 before use~ The required application quantity ~aries depending on the external conditions, 6uch `~ 6 .. , ` ~, ... . ~ . ` ` ....... -.: ` ` . , , , , ., - ` ~- ,, `. . .. . ..

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7~7 as temperature, moisture, inter alia. It can vary within wide limits, for example between 0.1 kg/ha and 10 kg/ha of active substance, but is preferably between 0.3 and 3 kg/ha.
The invention is illustrated in the following Examples. The compounds of Examples 3 to 18 are in accordance with above-mentioned Application Serial No. 278,456.
Example 1:
r(3-Amino-3-carboxy)-propyl-1]-methylphosphinic acid hydrochloride 22 g ~0.164 mole) of methyl-vinyl-phosphinic acid ethyl ester and 35 g ~0.161 mole) of acetaminomalonic acid diethyl ester are hea-ted together to 80C and after removing the heating bath, 3-5 ml of a 2% ethanolic sodium ethylate ;
solution are added. After a few minutes the reaction temperature increases to 90 - 95C. After the exothermic reaction has died down, stirring is con-tinued for approximately 4 hours at 80 - 85C.
500 ml of 25% hydrochloric acid is added to the oily reaction product and the whole is heated under reflux for 6 hours. After evaporating the reaction solution in vacuo 38 g (92% of the theoretical yield) of [(3-amino-3- ~
carboxy)-propyl-l]-methylphosphinic acid hydrochloride remain. The product -r' melts at 194 - 198DC with decomposition ~Lit. mp: 195 - 198C, German Democratic Republic Specification No. 116,236).
Example 2:
[(3-Amino-3-carboxy)-propyl-l]-methylphosphinic acid 120 g ~2.07 mole) of propylene oxide are added dropwise at approximately 25C
to a solution in 1.2 l of 80% ethanol of 220 g ~1.01 mole) of [(3-amino-3--carboxy)-propyl-1]-methylphosphinic acid hydrochloride. The reaction temperature is held : : . : ;:: .
, : : , :. , . ,: - ::
: , : -: . : :: ., 7~7 at approximately 25~30C during the dropwise addition. The reac-tion solution is subsequently oooled to 0C. After approxima-tely 3-4 hours the crystalline precipitate is suction filtered, washed with 94% ethanol and the prcduct is dried at 100C in a vacu~n chamber. 163 g (89% of the theoretical yield) of [(3-amino-3-carboxy)-propyl-l]-methylphosphinic acid are obtained. The amino acid melts at 229-231 & (Lit. : 241-242 & , ROCZ, Chem. 49, 2129) (1975)) with deccmposition.
Example 3:
Copper salt of [(3-amino-3-carboxy)-propyl-1]-methylphosphinic acid 18.1 g (0.1 mole) of [(3-amino-3-carboxy)-proyyl-1]-methylphosphinic acid are dissolved in 100 ml of water at 70 & and heated under reflux for 3 hours together with 11.5 g (0.1 mole) of Cu003.Cu(OH)2Ø5 H20. After oooling the reaction mixture the light blue salt is suction filtered. 17.5 g (72% of the theoretical yield) of copper salt of [(3-amino-3-carboxy)-propyl-1]-methylphosphinic acid, which melts at 257-258 & with decomposition, is obtained.
Example 4:
Disodi~n salt of [(3-amino-3-carboxy)-propyl-1]-methylphosphinic acid A solution of 8 g (0.2 mole) of NaOH in 20 ml of water is added dropwise at 70C to a solution of 18.1 g (0.1 mole) of [(3-amino-3-carboxy)-propyl-1]-methylphosphinic acid in 100 ml of water. The solvent is distilled off under reduced pressure and the . .
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residue is dried at 80 C under an oil pump vacuum. 21.8 g (97~ of the theoretical yield) of disodium salt of [(3-amino-3-carboxy)-propyl-l]-methylphosphinic acid, which melts at 300C with decomr position, is obtained.
Example 5:
[(3-Amino-3-carbomethoxy)-propyl-1]-methylphosphinic acid Hydrogen chloride is introd~lced into a paste of 100 g (0.46 mole) of [(3-amino-3-carboxy)-propyl-1]-methylphosphinic acid hydrochloride in 500 ml of methanol. The tem~erature thereby in-creases to 60 C and a clear solution results. Stirring is carried out for 1 hour at 60&, the methanol is evaporated off in va 300 ml of fresh methanol are added to the residue and hydrogen chloride is passed through the reaction solution again for 4 hours.
After evaporation, the residue is taken up in 150 ml of methanol and the solvent is distilled off again. This operation is repeated twice more. me residue is then taken up in 500 ml of methanol and propylene oxide is added until no more chloride ions cr~n be detected in the solution. The solution is left to stand overnight at 0C, the precipitated product is suction filtered and, by drying, 70 g (78~ of the theoretical yield) of methyl ester, which does not decompose below 105C, are obtained.
Example 5a:
[(3-Amino-3-carboethoxy)-propyl-l]-methylphosphinic acid hydro-chloride = =
Hydrogen chloride gas is introduoed into a paste of 21.75 g (0.1 mole) of [(3-amino-3-carboxy)-propyl-1]-methylphos-.

phinic acid hydrochloride in 100 ml of ethanol. m e reaction temperature thereby increases to 74C. Stirring is carried out for 1 hour at this temperature. Subsequently the ex oe ss ethanol is drawn off, 100 ml of fresh ethanol are addea to the residue and hydrogen chloride gas is passed through the reaction solution at 75C for 4 hours. Undissolved portions are then filtered off, the solvent is evaporated off under reduced pressure and the residue is dried in an oil pump vacuum. 21 g (85% of the theoretical yield) of ethyl ester hydrochlo A de are obtained. m e product is glass-like and strongly hygroscopic, so that a melting point could not be determined.
Example 6:
[(3-Pmino-3-carbamido)-propyl-1] ~-L yi~ osl~hinic a_ld 100 ml of a methanol solution saturated with ammonia gas are added, while cooling with i oe, to 15 g (0.768) of [(3-amino-3-c æbomethoxy)-propyl-l]-methylphosphinic acid in a pressure vessel.
The reaction mixture is shaken at room temperature for 4 days. Sub-sequently, the solvent and the ex oe ss ammonia æ e distilled off, and the residue is dried in an oil pump vacuum. 12 g (87% of the theoretical yield) of [(3-amino-3-c æbamido)-propyl-l]-methylphos-phinic acid, which melts at 245C with decomposition, are obtained.
Example 7:
[(3-~mino-3-carbanilido)-propyl-1]-methylphosphinic acid :
19.5 g (0.1 ~ole) of [(3-amino-3-carbomethoxy)-propyl-13-methylphosphinic acid æe mixed with 30 g (0.32 mole) of aniline and heated for 5 hours at 140C the methanol being distilled off.

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After cooling, the residue solidifies to a laoquer-like brown mass, which i5 extracted by boiling four times with 50 ml of benzene.
m e residue is made into a paste with a little water, and goes into solution. After a few minutes the anilide crystallizes out. It is suction filtered, washed with a little water, and recrystallized from water. 9.3 g (40% of the theoretical yield) of anilide, which melts at 253-254C with decG~position, are obtained.
The following ccmpounds are obtained in a similar manner to that in Examples 1 to 7:
Table 1 - . ..
R3 - C - C - (CH2)2 - P

(Rl = CH3, R4 = R5 = H) Example R2 R3 Mp. (&) Produced No. according to Example 8 O Na OH165 - 170 4 9 O N H3CH(CH3)2 OH 105 4 `

11 O-N+H OH +) 4 13 OH OC4H9(n)165 - 166 5 13a hydrochloride of 13 +) 5a 14 OH OCH2CH2OH +) 5 , ' ' ~7~7 Table 1 (continued) .
Example R2 R3 ~5P (C) Produced No. according to Example OH OCH2CH2CH20H-~) 5 +) strongly hygroscopic, melting point indeterminable Exam~_e 18:
[(3-Methyl-3-amino-3-ca~ vl~D ~ m~thyl os nic acid 136 g (1 mole) of the mono-n-butyl ester of methanephos-phonous acid are heated at 50 & for 48 hours with 70 g (1 mole) of methylvinyl ketone in the presence of 0.1 g of hydroquinone and

2 ml of tetramethyl guanidine. In the course of the reaction a further 5 ml of tetramethyl guanidine are added dropwise. Sub-sequently distillation is carried out under reduced pressure.
Yield: 28.5 g of 3-oxo-butylmethylphosphinic acid-n-butyl ester, bpo 3 : 130 &
20.6 g (0.1 ~le) of this intermediate product are mixed at 15C with 5.8 ml (0.15 mole) of HCN and 1 ml of triethylamine and the whole is left to stand for 24 hours. After rem~ving the ex oe ss HCN, 50 ml of ethanol and 34.2 g (0.3 mole) of (NH4)2003 are added and the reaction mixture is stirred for 4 hours at 50 to 55C
and half an hour at 75 C.
The ~ixture is then cooled, filtered and concentrated, a viscous, dark residue remaining. This is extracted several times 2~ with boiling a oe tonitrile. 5.8 g of 5-methyl-5-[~-(n-butylmethane-phosphonyl)-ethyl]-hydantoin crystallize out from ,.~,`' :, . ~. . :.
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the extracts. 508 g ~0.021 mole) o~ th~ r~sul.ting hydantoin are heated with 100 ml of lN I~aOH for 105 hours at 150C
in an autoclave. Subsequen~ly the mi2tuL~e is acidified with HCl and evaporated to dryness.
The resulting hydrochloride of [3-methyl-~-am~no-3-carbo~,y]~ropyl-(1)-methylphosphinic acid is separatad from the inorganic salts by e~tracting wi~h 99.5~ ~lcoholO ~fter concertrating to dryness and taking up in 70 ~o alcohol, 2.5 g of [3-methyl-3-amino-3-carbo~y]-propyl (1~-methylpho~phinic acid crystallize out after releas~'ng the amino group with prop~lene o~ide with one mole of water of cr~stallization (mp.
169~) ~or~ulation exam~le~

A wettable powder readily dispersible in water is obtained by mi~i~g a~d grinding in a pin mi11:

25 parts by weight o~ active substance 64 parts by weight of kaolin-containing quartz as inert substance 10 parts by weight of a potassium salt of ligninsulfonic acid, and 1 part by weight o~ a sodium salt of oleyl-methyltaurine acid a9 wetting and dispersing agent.

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Z~747 3IO~OGICAL 3XAl~ 3 amPle I: (Post-emergence applicaiion) Seed~ o~ a very wide variety of weeds ~rom numerous botanic2l groups are sown in pots and grown under appropriate greenhouse conditions for 3-5 weeks to a size o~ 3-12 cm depending on the ~ype of plant. Subsequently, the compound ~rom E~ample (1) in the form of a spray powder is spra~ed in various dosages onto the plants. After standing for 14 days in the greenhouRe, the action of the preparations is evaluated visually.
1~ Apart from the plants grown from seed, 3 grass-type weeds several ~ears old are included in the tests, these being damagiDg weeds that are economic~lly extremel~ important throug~-out the world, namely couch grass (A~ro~ron)? Bermuda grass (Cvnodo~) and Cv~erus ~aa~g~. Rhizome pieces o~ these p ants are transplanted into pots and grown in the greenhouse ~or 5-6 weeks u~til the plants have reached a size o~ 12-15 cmO
~hey a~e then sprayed with the compounds according to the invention. ~he evaluation o~ the results is carried out after 14 days.
The results of the tests are compiled in Table I, the evaluation having been under take~ according to Bolle's scheme (~achrichtenblatt des Deutschen Pflanzenschutzdienstes 16, 1964, 92-94) (see evaluation ccheme)O ~he test results show that the compound according to the invention successfull~ combats important, economically significant types of weed, especia11y such importa~t weed~ as I~omoe~ and other dicotyledons, a3 well as weeds several years old such as _~erus rotundus.

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' . ~ , :' .. , , ,~ ' . ., ". .. ' '.1 , ' 7gL7 Evaluation Scheme:

Evaluation Damaging action in % on number W~eds Crops _ 2 97.5 to <100 > O to 2.5

3 95 to < 97.5 > 2.5 to 5

4 90 to < 95 > 5 to 10 85 to < 90 >10 to 15 6 75 to < 85 >15 to 25 7 65 to < 75 >25 to 35 8 32.5 to < 65 >35 to 67.5 O -to < 32.5 >67.5 to 100 , . . ~

siological action in post-emergence method .
Cc~r~ound DoseType of Plant (kg/ha (EXample) A.S.)123456789101112 . _ .. _ _ ................. . . _ _ _ _ 2 2.5 111111141 0.6 221212641 3 9 2.5 122112111 0.6 252322444 3 1 4 4 2.5 141211121 0.6 232412441 6 2 5 8 2.5 131111121 1 1 2 0.6 452311312 1 1 3 2.5 11 ~ 112131 1 1 2 0.6 142314141 2 1 5 3 2.5 111554661 6 - 6 0.6 112757884 8 - 7 2.5 111113431 1 2 0.6 111216774 7 7 7 11 2.5 111111111 0.6 131115661 3 4 5 12 2.5 111214311 2 4 0.6 151117784 7 7 7 13 2.5 111114651 1 4 2 0.6 112115882 8 8 4 17 2.5 111114751 1 8 2 0.6 2151288 - 1 8 - 7 6 2.5 111111741 0.6 111116882 8 7 5 16 2.5 111113761 1 2 0.6 112116881 7 7 6 14 2.5 111113671 1 5 0.6 1121178 - 2 7 8 .

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Cb~pound Dose Type of Plant (kg/ha (Example) A.S.~ 1 2 3 4 5 6 7 8 9 10 11 12 2.5 1 1 1 1 1 5 7 8 1 3 6 0.6 2 3 6 1 1 8 - - - - - -1 2.5 1 1 1 1 1 1 1 1 1 2 2 2 0~6 1 1 2 3 1 1 6 4 1 3 3 3 7 4.0 1 - - 1 - - - - - - - -i8 2.5 3 4 6 5 1 5 7 - 5 - - 3 0.6 3 5 7 6 1 6 8 - 7 - - 4 Key:
Type of plant 1 = Sinapis 2 = Matricaria 3 = Chrysanthemum 4 = Stell æ ia = A~aranthus 7 ~ ~ . _ = _ _ . . _ . .
6 = Ipcmcea 7 = Avena 8 = ~lcpecuru:
9 = Setaria = Poa 11 = Lolium 12 = Echinochloa A.S. = active substance ;~

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Claims (3)

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

1. A method for combatting undesired plant growth which comprises applying to the plant or to the habitat of the plant a herbicidally effective amount of [(3-amino-3-carboxy)-propyl-1]-methylphosphinic acid or [(3-amino-3-carboxy)-propyl-1]-methylphosphinic acid hydrochloride.

2. A method according to claim 1 wherein [(3-amino-3-carboxy)-propyl-1]-methylphosphinic acid is used.

3. A method according to claim 1 wherein [(3-amino-3-carboxy)-propyl-1]-methylphosphinic acid hydrochloride is used.