Note: Descriptions are shown in the official language in which they were submitted.
~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.
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.. ~ :.~
~",
l~L12645 AG -1 0 9 8
,~
Z Z
`3 1` oo
~:1
~ ~ ~ U~
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:
a:
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,
~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 ~
: " ~ ~ ~
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~; r~ ~
: ~J O ~ '
~; r4 ~D
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~ _ ,
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_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
--5
~,
~ 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.
' . ' '~ ~
,.~
.
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-
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~,' '
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6~5 AG-l O 98
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a).o . I
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~D O
o
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r~
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:~ o . ~,
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:'.1 ~ ~
-., ~ C) o ~ ~ CO ~ .-
~ - X Z ~ ~ O O
, -:1H O- ~_) C,' - O SL) ~ . . . . `~
`.~'J ~ /~
~ ~ U~
.. ,o '~ Lr, o ~ a~ : - -.;
.'~ ~ -.,.
,`' ~ C) ~ ~: '
.; O ~ ~ ~ In ' :':
:. QI co
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., ~
:~
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V V r~
1~ 1~ ~ ~ V~
: ~:`
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AG-1098
CO
~r o ~
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Z Ou~
a~
C) ~ ~ ~ ~
S ~ ~~1 ~1 0
a) ~ . . .
:
~, ~ O N 0~
O ~ N N t'`l ~ r
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OCJ! N N
. ~ U~ ~ ':~ N
''`' ~
t` CO C~' ~ ' '
~r ~ o o
,
0~ a~
t~ .~ ~ O o
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: E~ aJ ,1
a~ 0~ ~0
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k
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--8--
~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.
': '`
': ~
AG-1098
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
--10--
AG-1098
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
1 67
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,
AG-1098
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
1300
2060
1940 2940
1650 1540
174 0 1680
1700 I740 1720
1910 2170 1660
1810 2430 1390
1850 2230 1480
1770 1730 1130
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~.
-15-
