CA1112645A

CA1112645A - N-pyridyl-phthalamic acid compounds

Info

Publication number: CA1112645A
Application number: CA293,560A
Authority: CA
Inventors: Frederic G. Bollinger; John J. D'amico; Dale J. Hansen
Original assignee: Monsanto Co
Current assignee: Monsanto Co
Priority date: 1976-12-22
Filing date: 1977-12-21
Publication date: 1981-11-17
Also published as: IT1090352B; FR2387960A1; ZA777589B; AR220111A1; PH16343A; PL106999B1; IL53671A0; BE862113A; JPS6134421B2; FR2381029A1; JPS5379871A; FR2381029B1; DD133884A5; GB1573576A; SU942573A3; CS196411B2; AU516014B2; DK571377A; IL53671A; AU3187777A

Abstract

Abstract of The Disclosure Aromatic acids having the following formula

Description

~1264L5 AG-l 098 PHT~LAMIC ACIDS AND NICOTINIC ACIDS
AND THEIR USE AS PLANT GROWTH REGULANTS
_ _ __ _ _ _ _ _ _ This invention relates to novel phthalamic acids and nicotinic acids and the salts thereof. Said compounds are useful as the active ingredient in plant growth regulating compositions~ More particularly, the invention relates to the use of novel compounds having the formula C - OR
NH - R2 (I) wherein R is hydrogen or lower alkyl; Rl is carbon or nitrogen;
R2 is pyridyl, substituted pyridyl or when Rl is nitrogen, R2 may be substituted phenyl; and agriculturally acceptable salts ~; thereof. -The term "substituted pyridyl" as used herein is understood to mean those radicals having the formulae ~X ~X _~X ~:

wherein X and Y are independently selected from the aroup con-hydro~ e~, ~i sisting of/halogen, CF3/ lower alkyl and lower alkoxy; provided that neither X nor Y may be chlorine in the 4 position when the nitrogen atom is in the 3 position.
The term "substituted phenyl" as used herein is understood to mean those radicals having the formula ~X
.. ~ Y
wherein X and Y are defined as above.
As used herein, the term "agriculturally acceptable salts" includes alkali rnetal, substituted amine, such as isopropylamine and triethylamine and amrnonium salts.

-2-~ AG-1098 The terms '?lower alkyl" and "lower alkoxyl' are understood to include those alkyl and alkoxy radicals having from oIle to four carbon atoms inclusi~e.
The phthalamic acids may be prepared by adding a stoichiometric equivalent of the appropriate aminopyridine to a slurry containing phthalic anhydride and chloroform. After stirring at room temperature, the preCipitatQ may be filtered and air-dried. To illustrate the preparation of the novel phthalamic acids, the following examples are presented.

~ ' ~`' To a stirred slurry containing 0.1 moles of phthalic anhydride and 100 ml. of chloroform, 0.1 mol~s of 3-amino-2-chloropyridine was added in one portion. The reaction mixture was stirred for 24 hours. The precipitate was filtered, air-dried and identified as N-(2-chloro-3-pyridyl)phthalamic acid ~ having a melting point of 203C. (~ yield = 87) `~ Anal. Calc'd. C1, 12.81; N, 10.12 Found Cl, 12.94; N, 10~37.
` In accordance with the procedure of Example 1, the following compounds have been prepared.

"; . : .

.. ~ :.~
~", l~L12645 AG -1 0 9 8 ,~
Z Z
`3 1` oo ~:1 ~ ~ ~ U~
O
:
a:
.~ .~
.~ rt~
, ~C) CX~ W
to .
,~ V Z; V -:~ :;
o :, ~ r~ ,~, o o ., Z Z
. a) ~ co .
.~ ~ ~ .
er ~ U7 ,, ~ "
~' o ~
~ ~d :, ~ ~ .~
o .~ ~r ~ , ,~ . , .
:. r~
v æ v - r i-. ~r~ r~
~3 V 5 ~ i ,' ~
:,-. O 5-1, ~ I
: ` O I ~ ,~
,. V ~
: " ~ ~ ~
- ~ O O E3 ~; r~ ~
: ~J O ~ ' ~; r4 ~D
I
~ _ , z æ æ
Q) 1~5~1 ~d~

_4 _ ~ D~5 AG-1098 The sodium salt of the novel phthalamic acids may be prepared by stirring for one hour a stoichiometrically equivalent amount of 50% aqueous NaOH and 400 ml. of water for a 0.1 mole reactionO In accordance with this procedure~ the following compounds have been prepared.
Example Compound .
Sodium salt of N-(5-chloro~2-pyridyl)phthalamic acid 6 Sodium salt of N-(2-chloro-3-pyridyl)phthalamic acid Ammonium and substituted amine salts may be prepared in accordance with the following examples.

Exa_ple 7 To a stirred slurry of 0.1 moles of N-(2-chloro-3-.~ , -pyridyl)phthalamic acid and 500 ml. of ethyl ether, 0.11 moles of isopropylamine, to form the isopropylamine salt, was added - 15 in one portion. After stirring at 25-30C.~for 24 hours, a ~' - solid was collected by filtration and air-dried. The product, m.p. 147~148C., was obtained in 100% yield.
Anal. Calc'd. C, 57.23; H, 5.40; C1, 10.56; N, 12.61 Found C, 57.68; H, 5.45, Cl, 10.71; N, 12.59.

Example 8 -The procedure of Example 7 was followed to prepare the isopropylamine salt of N-(5-bromo-2-pyridyl)phthalamic acid, ' m.p. 145-146C., in 87% yield. -Anal. Calc'd. C, 50.54; H, 4.77; N, 11.05 Found C, 50.42; H, 4.73; N, 10.99. ;~
The nicotinic acids of the present invention may be prepared by adding 0.1 moles of the appropriate substituted aniline or aminochloropyridine to a slurry of 0.1 moles of 2,3-pyridinedicarboxylic acid anhydride and 100 ml. of chloroform. After stirring at 25-30C. for 24 hours, the solids ~, ~ 45 AG-1098 are collected by filtration and air-dried at 25-30C. The compounds of Examples 9-16, summarized by Table I below, were prepared in accordance with the above procedure.

' . ' '~ ~

,.~
.
":--~
~,' ' .~' ~`

6~5 AG-l O 98 CO o ~: ~ I , æ o c~
.,, ~.
~ I` ~ ~1 ~ ~ I
a).o . I
' ':
I~ ~ O
~D O
o ~:
.
r~
a~
o . ~ ~ ~ ~ ~ ~, .
:~ o . ~, . ~
~ . .
:'.1 ~ ~
-., ~ C) o ~ ~ CO ~ .-~ - X Z ~ ~ O O
, -:1H O- ~_) C,' - O SL) ~ . . . . `~
`.~'J ~ /~
~ ~ U~

.. ,o '~ Lr, o ~ a~ : - -.;

.'~ ~ -.,.
,`' ~ C) ~ ~: ' .; O ~ ~ ~ In ' :':
:. QI co ,. ~ ~
., ~

:~
~ ~:
V V r~
1~ 1~ ~ ~ V~

: ~:`

~ ~ o ~ ~

CO
~r o ~
~ . I
Z Ou~
a~
C) ~ ~ ~ ~
S ~ ~~1 ~1 0 a) ~ . . .

:
~, ~ O N 0~
O ~ N N t'`l ~ r . ~ '-:
~ ' . ' ':'.' OCJ! N N
. ~ U~ ~ ':~ N
''`' ~

t` CO C~' ~ ' ' ~r ~ o o , 0~ a~
t~ .~ ~ O o I I h- ~ ~ I N
O ~ O O
,~ U ~ u~

~: R ~ ~1 i~ ~ ~ 1 : E~ aJ ,1 a~ 0~ ~0 ~ _ _ _ __ o o .~ .~ ~ ~ o o U~
~ ) r-l f O ~ ~ r~
F~ o ~ ~ N ,~ ~ O
.n oo ~ oo ,~ ,~ ~ ~ ~ ~o : ~ ~ Z ~l :
g O O ~ ' , ~
~ ~, O
" N
~4 ,J ,_1 ,_1 ,_1 h a) ~b a) O t r-l ~ ~ 1~
k ~ ~I r-l r^l r-l ~ ~ _ _ ~2~ AG-1098 Esters may be prepared as follows.
EXample 17 To a stirred slurry containing 27.7 grams (0.1 moles) of N-(2-chloro-3-pyridyl) phthalamic acid and 300 ml. of methyl alcohol, 71 ~rams (0.5 moles) of boron trifluoride etherate [(C2H5)2O-BF33 is added in one portion. An exothermic reaction set in causing a temperature rlse from 21 to 33C The stirred mixture is heated at reflux for 24 hours. After cooling to -10C., 1000 ml. of a 10~ aqueous sodium bicarbonate solution -~ 10 is added slowly at -10 to 0C. After stirring at 0 to 10C.
for 30 minutes, the solid is collected by filtration, washed with water until neutral and air-dried at 25-30C. The product -~ which is the methyl ester of N-~2-chloro-3-pyridyl)phthalamic", acid, m.p. 110-112C., is obtained in 76~ yield. After two recrystallization from heptane/isopropyl alcohol, it melted ~-at 122-124C.

Anal. Calc'd. for C14H11ClN2O3: C, 57.84; H, 3.81; Cl, 12.20; ;

N, 9.64. --Found: C, 57.88; H, 3.57; Cl, 12.45;
,: :
N, 9.41.

': '`

': ~

6~;

The compounds represented by Formula I above have been found to be effectlve in altering the development of both the male (tassel) and female (ear) reproductive components of corn plants. As used herein, the alteration of the "development of the reproductive component" of the corn plant is understood to mean the modification of the normal sequential development of said component to maturity. Such modifications ~-- are most readily observed as inhibition of tassel growth, inhibition of latexal tassel branches, alteration in ear numbers, shape, position, kernel numbers, speed of silking, etc.
The invention contemplates the alteration of the development o the reproductive components of healthy corn plants by applyin~ an effective, non~lethal amount of the acids of Formula I to said corn plant before or during the early stages of the development of said reproductive component referred to herein as reproductive differentiation. As a result of such application, tassel size can be reduced or eliminated, thus reducing or eliminating the labor required by hybrid seed corn producers to manually detassel said corn plants. Additionally, the amount of seed per ~Lit area of land may be increased by applying an effective amount of the active ingredient before or during the early stages of the development of said ear.
As used herein, the term "active ingredient" refers to the acids of Formula I.
In accordance with the novel aspects of the present invention, compounds 1-16 were tested in accordance with the following procedure.
E~ample A
A-619 variety corn plants were grown and thinned to obtain a uniform population. All weak or late plants were removed before chemical application. The active ingredient was formulated by adding 50 or 100 mg. of the active ingre-dient to 7~5 ml. of acetone and 7.5 mlO of water. 0.25~ Tween 20 was added as a surfactant. Utilizing a Devilbiss #152 sprayer, the corn plants were sprayed during the early stages of reproductive differentiation at a rate of 10 mg. per plant ; or 20 mg. per plant.
Results were analyzed by comparing the treated plants to control plants which were not chemically treated. Chemicals were considered to be active in altering the reproductive ~-~
development of the corn plant if treatment resulted in an ~; inhibition of at least 25 percent of the lateral tassel forma~
tion when compared to the control plants.
In accordance with the above procedure, compounds ~, 15 1, 2, 5, 6 and 9-11 were found to be; effective in inhibiting from 50 to 74 percent of the lateral tassel development.
Compounds 3, 7, 8 and 12~16 were found to be effective in inhibiting from 25 to 49 percent of the lateral tassel development. In addition, flowering was inhibited as illus-trated in Table II.
Table II

cm. of CompoundFlowers ~ .
Control 224

3 132

4 75 Example B

In another test, N-(2-chloro-3-pyridyl)phthalamlc acid was applied to corn plants as a formulation described above. Responses noted included alteration of ear height, 6~5 . . .
increased speed of silking and partial sterility. Table III
illustrates the responses noted.
Table'I'II

Rate of Treatment Ear Percent ; 5kilos/he,c~are Height of Male Day g(a) Day 12~a) Day 15(a,)(cm) Sterility o 0 0 48 0 1.12 1.12 0 73 80 1.12 0 1.12 54 88 ' 10 1.12 0.56 0 57 75 1.12 0 0.56 52 89 0.56 1.12 0 60 68 0.56 0 1.12 48 95 0.56 0.56 0 55 74 0.56 0 0.56 48 88 (a~ from seedling emergence.

As exemplified above, the lnvention contemplates the application of the phthalamic acids before or duriny the early stages of the reproductive differentiation. Repro-ductive differentiation occurs at different times dependingupon the variety of corn plant as well as environmental factors. , ; For example, male reproductive differentiation of Gaspé corn begins during kernel formation while reproduction differen-tiation of A-619 corn begins within the first 8 to 12 days ' 25 after seedling emergence. The determination of when repro-ductive differentiation occurs is within the skill of the art. By way of example and for purposes of illustration only, applications for most varieties used in the Midwest of the U~ited States r~nging from 3 to 25 days after seedling emer-gencearedesirable. Varieties used in foreign countries mayre~uire applications ranging from 1 to 40 days from seedling emergence. The following example illustrates that for A-619 ~L~126~L5 AG-1098 :
variety corn, applications between 7 to 12 days after seedling emergence are preferred. r Example C
, . ~
Corn, A-619 variety, was planted in plots at a rate

5 of 64,000 plants per hectare. These plants were treated at rates ranging from 0.56 to 1.68 kilos per hectare with a formulation consisting of compound 6, 50 percent acetone, 0.25 .
percent Tween 20 and a sufficient amount of water such that ~` said formulation was applied at a rate of 320 liters per 10 hectare. Some applications were made early, on or before 12 . , days after seedling emergence. Other applications were made late, after 12 days from seedling emergence. After harvest, the yields of the treated plants were compared to those of the untreated control plants. Table IV illustrates the results -of this test.
Table IV

Grams/Plot Early Late Control_Yields A~p~ Application Mean 1773 2057 1476 In the practice of the invention, the active ingre-dient can be used alone or in combination with a material referred to in the art as an adjuvant in either liquid or solid form. To prepare plant growth regulating compositions, the 35 active ingredient is admixed with an adjuvant including diluents, extenders, carriers and conditioning agents to provide compositions in the form of finely-divided particulate solids, granules~ pellets, wettable powders, dusts, solutions ]3--~ 6~ AG-lO98 and aqueous dispersions or emulsions. Thus, the active i.ngre-dient can be used with an adjuvant such as a finely-divided particulate solid, a solvent liquid of organic origin/ water, a wetting agent, dispersing agent or e~lulsifying agent or any suitable combination of these.
; Illustrative finely-divided solid carriers and `~ extenders which are useful in plant growth regulating compo-; sitions of this invention include the talcs, clays, pumice, silica, diatomaceous earth, quartz, Fullers earth, sulfur, powdered cork, powdered wood, walnut flour~ chalk, tobacco dust, charcoal and the like. Typical liquid diluents include ~-Stoddard solvent, acetone, alcohols~ glycols, ethyl acetate, benzene and the 1i~e. The plant growth regulating compo-sitions of this invention, particularly liquids and wettable powde~s, usually contain one or more surfac -active agents in amounts sufficient to render a given composition readily dispersible in water or in oil. The term "surface-active a~ent" is understood to include wetting agents, dispersing agents, suspending agents and emulsifying agents. Such surface-active agents are well ~nown and reference is made to U.S. Patent No. 2,547,724, Columns 3 and 4, for detailed examples of the same.
Generally, the active ingredients are applied in the form of a composition containing one or more adjuvants which aid in the application of a uniform distribution of the active ingredient. The application of liquid and particulate solid compositions of the active ingredient can be carried out by conventional techniques utilizing, for example, spreaders, power dusters, boom and hand sprayers and spray dusters. The composition can also be applied from airplane~ as a dust or spray.

~G-1098 `~Compositions of this invention generally contain from about 1 to 99 parts active ingredient, about 1 to 50 -~parts surface-active agent and about 4 to 94 parts solvents, all parts being by weight based on the total weight of the composition.
In selecting the appropriate rate of application of the active ingredient, it will be recognized that precise rates will also be dependent ~upon the mode of application, plant variety, soil conditions and various other factors known to those skilled in the art. While a rate of about 0.056 to 5.6 kilos per hectare is preferred, higher rates of up to 56 kilos per hectare may be used, depending upon the :factors noted above.
This invention, however, does not contemplate the ;~
15 use of phytotoxic rates wh.ich exert a herbicidal effect. In ~;
addition, it will be recognized that single or multiple -~
applications may be used to exert the desired response.
Although this invention has been described with respect to speciEic modifications, the details thereof are not to be construed as limitations, for it will be apparent that ~;
various equivalents, changes and modifications may be resorted to without departing from the spirit and scope thereof and it ~ .
is understood that such equivalent embodiments are intended to be included herein~.

Claims

The embodiments of the invention in which an exclu-sive property or privilege is claimed are defined as follows:

1. A compound having the formula (I) wherein R is hydrogen or lower alkyl; R2 is substituted pyridyl and agriculturally acceptable salts thereof, said substituted pyridyl being selected from the group consisting of:

, , (II) (III) (IV) wherein X and Y are independently selected from the group consisting of hydrogen, halogen, CF3, lower alkyl and lower alkoxy; provided that neither X nor Y may be chlorine in the 4 position when the nitrogen atom is in the 3 position;
and with the proviso that when the pyridyl is that of Formula III, when one of X or Y is lower alkoxy, the other of X or Y is other than H.

2. A compound according to claim 1 which is N-(2-chloro-3-pyridyl)phthalamic acid.

3. A compound according to claim 2 which is the sodium salt of N-(2-chloro-3-pyridyl)phthalamic acid.

4. A method for altering the development of the reproductive components of a corn plant which comprises applying to said corn plant an effective, non-lethal amount of a compound of the formula (I) wherein R is hydrogen or lower alkyl; R2 is substituted pyridyl and agriculturally acceptable salts thereof, said substituted pyridyl being selected from the group consisting of:
(II) (III) (IV) wherein X and Y are independently selected from the group consisting of hydrogen, halogen, CF3, lower alkyl and lower alkoxy; provided that neither X nor Y may be chlorine in the 4 position when the nitrogen atom is in the 3 position; and with the proviso that when the pyridyl is that of Formula III, when one of X or Y is lower alkoxy, the other of X or Y is other than H.

5. A method according to claim 4 wherein said compound has the formula wherein R2 is substituted pyridyl.

6. A method according to claim 5 wherein said compound is N-(2-chloro-3-pyridyl)phthalamic acid.

7. A method according to claim 5 wherein said compound is the sodium salt of N-(2-chloro-3-pyridyl)phthalamic acid.