Note: Descriptions are shown in the official language in which they were submitted.
1066708
This invention relates to certain diphenylheterocyclic
compounds useful in regulating the growth of, or killing,
plants, to a process for preparing them and to method of
regulating the growth of, or killing, plants using them.
S The compounds have the general formula (I) :
R4 R7
R3 ~ R5 R6 ~ R8 (I)
~2 ~ ~ Q ~ R9
R1
wherein each of R1 to R10, which may be the same or different,
is hydrogen, lower alkyl, halogen, amino, nitro, cyano or
-CORll wherein Rll is hydroxy, lower alkoxy, aralkoxy,
aryloxy, unsubstituted amino or ~~ 7n Mn0 or -S~ 7n Mn0
wherein Mn0 is an ammonium, alkali metal or alkaline earth
metal ion and n is 1 or 2 accordingly, Rl being -CORll, at
least three of R2 to RS being hydrogen and at least four of
R6 to R10 being hydrogen and wherein Q is a heterocyclic
ring which is isoxazole-3,5-diyl, thiazole-2,4-diyl, 1,2,4-
triazole-3,5-diyl, 1,3,4-thiadiazole-2,5-diyl, 1,2,4-oxadiazole- - -
3,5-diyl or 1,3,4-oxadiazole-2,5-diyl.
The halogen atom is suitably a chlorine atom preferably
in the o- or ~- positions but it can be a bromine or iodine
atom.
, ' ' :, ,.: ., ~:
1066708
The t~rms "lowe~ alkyl" and "lower alkoxy" as used
herein refer to groups containing 1 to 6 carbon atoms.
Examples of these preferred compounds of the invention
are shown in Table (I),
- 3 - ::--. -
'' ' - ,
'
s~ ~
,, " ", " ". " ,.. , ":, . . ," : .. ,:, ,, " " ,, ", ,~ ' : x; ' ~
`- 1066~708
TABLE I
O - N
/1
__
~43
. HN N
,` ~
. .
~ .
,,
- 4 -
:,
.. . ,. .. - . ..
- . ` . .: :
.~
.
.` ' ., ` ' '` ~ . ~.
1066708
The compositions of the invention comprise the
compounds of general formula (I) and a carrier, e.g.
one comprising a diluent and/or surface active agent.
The compositions of the invention are of use
either as plant growth regulants or as herbicides. The
activity obtained using any particular composition
depends inter alia on the concentration of the active
ingredient, the time or rate of application of the
composition, and upon the plant species being treated.
The compositions can be used in treating both
monocotyledonous and dicotyledonous plants and may be
applled in either a pre- or post-emergent manner. When
applied in a post-emergent manner either the roots or
foliage of the plants may be treated, the former for
example by aqueous foliar spray.
The solid compositions may be in the form of seed
dressings, dusting powders or granules, wherein the
active ingredient is mixed with a finely divided solid
diluent, e.g. kaolin, bentonite, kieselguhr, dolomite,
calcium carbonate, talc, powdered magnesia, Fuller's
; earth and gypsum. They may also be in the form of
dispersible powders or grains, comprising a wetting agent
to facilitate the dispersion of the powder or grains in
liquid.
Liquid compositions are generally preferr`ed
especially for foliar application, since they are more
convenient to use.
-5-
.. ..
. . : . . . : .
~, . ... . .... ... . .. :
- . .: . ... . . . . , .
, . : . .... . , ~ . ,
- ' : .'' ' ' ~ :.... ' ~. .
: .: . .... .. .
,' ~, ' : " : '.,~ ' .:
1066708
Liquid compositions include aqueous solutions,
dispersions or emulsions containing the active ingreaient
together with surface-active agent(s) such as wetting
agent(s), dispersing agent(s), emulsifying agent(s), or
suspending agent(s).
Surface-active agents may be of the cationic,
anionic, or non-ionic type. The cationic agents are, for
example, quaternary ammonium compounds (e.g. cetyltrimethyl-
ammonium bromide). Suitable anionic agents are soaps;
salts of aliphatic mono esters or sulphuric acid, for example
sodium lauryl sulphate; and salts of sulphonated aromatic
compounds, for example sodium dodecylbenzenesulphonate,
sodium, calcium, and ammonium lignosulphonate, butylnaphthal-
enesulphonate, and a mixture of the sodium salts of di-
isopropyl- and triisopropyl-naphthalene-sulphonic acid.
$uitable nonionic agents are the condensation products of
ethylene oxide with fatty alcohols such as oleyl alcohol
and cetyl alcohol, or with alkylphenols such as octyl- or
nonyl-phenol or octylcresol. Other non-ionic agents are
.
the partial esters derived from long chain fatty acids
and hexitol anhydrides, for example sorbitan monolaurate; -
the condensation products of the partial esters with ethylene
oxide; and the lecithins. Suitable suspending agen~s
., ~ ,
are hydrophilic colloids, for example polyvinylpyrrolid~ne
and sodium carboxymethylcellulose, and the vegetable
gums, for example gum acacia and gum tragacanth. ~-~
.
. ~ , . , , :.
6 ~ -
.
.
.: .
1066~708
The aqueous solutions, dispersions or emulsions
may be prepared by dissolving the active ingredient in
water or an organic solvent optionally containing wetting,
dispersing, or emulsifying agent(s) and then, when
organic solvents are used, adding the mixture so obtained
to water optionally containing wetting, dispersing or
emulsifying agent(s). Suitable organic solvents are
ethylene dichlorlde, isopropyl alcohol, propylene glycol,
diacetone alcohol, toluene, kerosene, methylnaphthalene,
the xylenes and trichloroethylene.
The composltions for use in the form of aqueous
solutions, dispersions or emulslons are generally supplied
ln the form of a concentrate contalning a high proportion
of the actlve ingredient, and the concentrate is then
diluted with water before use. These concentrates are
-` usually required to withstand storage for prolonged
periods and after such storage, to be capable of dilution
with water to form aqueous preparations which remain
homogeneous for a sufficient time to enable them to be
applied by conventional spray equipment. Concentrates
conveniently contain 10 - 8S%, preferably 25 - 60~, by
weight of the active ingredient(s). Dilute preparations
ready for use may contain varying amounts of the active
ingredient(s), depending upon the intended purpose; amounts
of 0.01~ and 10.0%, preferably 0.1~ and 1%, by weight of
active ingredient(s) are normally used.
.;
-7-
.' `'
,. . .. . .. . . . .. . . ..
-, : . :
, : , , ; . :. . :
1066708
The composit~ons for use as plant growth regulators
may also contain other plant growth regulating agents,
for example maleic hydrazide, chlorflurecol and
carbetamide. Such plant growth regulating agents may
also be herbicides effective against broad leaved weeds,
particularly such herblcides which are selectlvely active
agalnst broad leaved weeds, for example hormone herbicides
such as 2,4-D, MCPA, mecoprop and dichlorprop.
The plant growth regulating effects are manifested
chiefly as a stunting or dwarfing effect in the plants
to which they are applled. Such stunting or dwarfing may
be us~ful, for example, in cereals, where reduction in
stem growth may reduce the risk of lodging. It may also
~ be useful in stunting the growth of sugar cane thereby
- 15 increasing the concentration of sugar in the cane at
harvest. Grass may be treated to siow down growth, so
J that it need not be mown so often.
The compounds can also have a plant stimulating
effect e.g. they can increase the shoot growth of vine
seedlings.
The amount of active ingredient compound applied
to regulate the growth of plants will depend upon a
number of factors, for example the particular formulation
i-~
selected for use, whether the compound is to be applied
for foliage or root uptake, the effect desired, and the
identity of the plant species in question. However, an
appllcation rate of 0.5 to 20, preferably 2 to 5, kg per
hectare is generally suitable. Where herbicidal effects
,. . .
' -8-
_. -. . , . . - - , . - . ~ ............ , ,., , ~.. , - .
- . , . ' .: . ~:, :, '.. . - -.,- . -
1066708
are desired, the rates used are naturally in general
higher than for growth stunting. In all cases, routine
tests are necessary to determine the best rate of
application of a specific formulation for any speclfic
purpose for which it is suitable.
Certain of the compounds of general formula (I)
are novel compounds. The lnvention thus provides the
compounds of general formula (I) wherein Rl to R and
A as defined above, with the additional proviso that when
A is a ring of general formula (B) and X is oxygen, then
Y and Z may not both be imino nitrogen.
The compounds of general formula (I) may be prepared
by known methods, the particular method being primarily
chosen according to the nature of A. These methods are
illustrated in Table II.
. ,
TABLE II
Examples of SYnthetic Routes to Compounds of Formula
X A - Y
whereln X = R3 ~ RS
R
` ~1
R7
. R6`~_ R8
and Y =
. R10
~ ' :
_g_ : -
. , , , -- , . .
.. , . , . : .
. ., ;. ~ . ~ , . ~
, , ,~ , ,,
. '
' ' ~'
-
1066~08
and wherein Rl to R10 and Z are as deflned above.
Moiety A Preparation - General Method
- XCN + Y - C
1,2,4-Triazole ~NH-NH2
oxidiz e H
,
% 1l CH2 ~ ICl ~ Y heat ~ X~Y
Isoxazole HO O - N
~ . .
`~.0 X C~O+Y ~
. H H-NH2
1,3,4-Oxadiazole hOeadi 3 ~ Y
~` I I
R5 ~ _ I
1,2,4-Oxadiazole ~ \ O ~ Y - C~
. R3- ~ C /o ~NH-N~2
:~ ~ X~y: I
`''I :, ~
~10-~
: : . , . , : , , -. ~ , . : :
, :, , , : .
. ,, . :,~ ', . ,, : ,
1066708
The invention therefore provid~s:
(1) a process for preparing a compound of general formula
(I) wherein Q is 1,2,4-triazole-3,5-diyl and Rl is COOH, the
process comprising oxidising a compound of general formula
(I) wherein Q is 1,2,4-triazol.e-3,5-diyl and Rl to Rl are
as defined above, subject to the proviso that R is lower
alkyl;
(2) a process for preparing a compound of general formula
(I) wherein Q is isoxazole-3,5-diyl, the process comprising
cyclising a compound of general formula (II):
C-CH2-C ~ R9
O NOH
wherein Rl to R10 are as defined above;
,. .
; (3) a process for preparing a compound of general formula
~ (I) wherein Q is isoxazole-3,5-diyl, the process comprising
`- reacting with hydroxylamine, a compound of general formula ~ ::
: 15 (III):
R4 R7
R3 ~ ~
_O CH-C R10
- o X o
.. .. .. ..
-- 1 1 --
.-, i
A~ , i
. .; . . . .; ... . .. . . .
.. ... , ... .. . ~ ,. .. ... .
. , " . .,~ .. ..... . ~ , .
. " , , . . ~,, ,, .
... .. ..... . . .. . . . . .
1066708
wherein Rl to R4 an~ R6 to R10 a~e as ~efined abo~e! and
is halogen (e.g. chlorine, bromine or iodine);
(4) a process for preparing a compound of general formula
~I) wherein Q is 1,3,4-oxadiazole-2,5-diyl and Rl is COOH,
the process comprising oxidising a compound of general
formula (I) wherein Q is 1,3,4-oxadiazole-2,5-diyl and R to
R10 are as defined above subject to the proviso that Rl is
lower alkyl;
~5) a process for preparing a compound of general formula
(I) wherein Q is 1,3,4-oxadiazole-2,5-diyl, the process
comprising oxidising with cyclisation a compound`of general
formula (IV): R4 R7
2 ~ CU=NNHC ~ R (IV)
; R R10
,'' .
' wherein Rl to R10 are as defined above;
- . .
~6) a process for preparing a compound of general formula
~ 15 (I) wherein Q is thiazole-2,4-diyl, the process comprising
.~ xeacting a compound of general`formula (V):
.
R4 -
R ~ RCSCH2X ~V)
.
. - 12 -
,' ' '
;~i' ' I
- 1066708
wherein Rl to R5 and X are as defined above; with a corlpound
of the general formula (VI): R7
R6 ~ R8
S ~ ~ R9 (VI)
H2N R10
wherein R6 to R10 are as defined above, and if neccssary or
desired hydrolysing any ester formed; and
(7) A pxocess for preparing a compound of general formula
~I) wherein A is 1,3,4-thiadiazole-2,5-diyl and Rl is COOH,
the process comprising oxidising a compound of general
formula (I) wherein A is 1,3,4-thiadiazole-2,5-diyl and
to R10 are as defined above subject to the replacement
proviso that Rl is lower alkyl.
` The invention is illustrated by the following Examples.
.~- - :.
1`~ .
- EXAMPLE 1
This Example illustrates the method of the present
`~ inventiQn wherein the growth regulant composition is applied
, , .
to the roots of plants.
In the following test, the compound was applied to the
roots of test plants grown in sand in flower pots. When the
roots of the plants were established in this medium, 25 ml -
of a dilute aqueous emulsion comprising 500 ppm of 3-(o~
carboxyphenyl)-5-phenylisoxazole was applied to saturate the
sand within the pot. The percentage reduction in size of
treated plant compared with untreated control plants was
assessed after 10 days.
- 13 -
,' ` ~ ~' '
.' ~ , , ''~
" .
;, : .,: ' , ' , ', . ` ' ' : ' . ~ ' .
~ 1066708
The results are given in Table III below.
TABLE III
Test Plant% Reduction in Other
Size Obser~ations
Wheat 15 Increased number of
sideshoots. Root growth
severely inhibited.
Barley 20 Leaves paler green
Brussel 20 Inhibition of apical
Sprouts growth.
EXAMPLE 2
This Example illustrates the method o~ the invention
wherein the growth regulant composition is applied to the
foliage of plants.
- 5 Test plants grown in pots as in Example 1 were
sprayed with a dilute aqueous emulsion comprlsing
3{o-carboxyphenyl]-5-phenylisoxazole at a rate equivalent
to 5 kg/ha (the volume of liquid used being equivalent to
1000 l/ha). The plants were observed after 14 days and
compared with untreated control plants. The results are
shown in Table IV below.
.
TABLE IV
: ,
Test Plant Effect of foliar application of 3~ ~-
carboxyphenyl~-5~phenylisoxazole
'~i
f Barley 10% reduction in growth
Tomato Reduced leaf area
Brussel Sprouts Accelerated leaf senescence
i
-14-
.- - .: , , , ;: : : . , ,: :
. , . - , . . ..
, , : , : . . , : . : .
:: , , . . . :
.: . .. ,, . ." .
,
, . : , :
1066708
Example 3
A grass sward in an old pasture was cut to a
constant level and then dressed with nitrogenous fertilizer
to encourage vigourus new growth. Plots (3 x 2 m) were
pegged out on the grass and 10 days afterwards a group of
3 such plots was sprayed with a dilute aqueous emulsion
comprising 3-to-carboxyphenyl]-5-phenylisoxazole at a
rate equivalent to 1 kg per hectare, and a second group
;` of 3 plots was retained untreated as a control. The a~ueous
sprays were applied at a volume equivalent to 400 litres/
hectare.
Observations of the plots were made 14 days and
22 days after treatment and it was notice~ that the grass in
the treated plots had grown considerably less than that in
the control area. The results are presented in Table V
` below.
~ Table V
;~J
. . . ,,,.
Rate of Application of ~ Growth reduction of rass
Active Ingredinet Compound After 14 days After ~ days
~. . _ .. ..
, 20 1 kg/ha 68 61
2 kg/ha 73 77
~ . . . ._.
: . . ._ - . .. _
Example 4
This Example illustrates the method of the invention
in modifying the root geotropism of plants.
Seeds of cress (LeFidium satirum) were allowed to
germinate on agar in a Petri dish until the roots were 1 cm
long. Agar compositions, each comprising one of the com- -
pounds listed in Table VI below and present in the concentration
,, ' :'
- 15 -
1066708
indicated therein, were prepared in Petri dishes and three
seedlings were transferred to the surface of each of these
compositions.
For the purpose of comparison a group of seedlings
were transferred to a Petri dish containing agar comprising
no active ingredient compound.
Each of these Petri dishes was then turned verti-
cally so that their root tips initially pointed horizontally,
and were then placed in darkness at 24C ~or 24 hours. At
the end o~ this period, the plants were examined for any
alteration to their normal response to gravity.
It was observed that the roots of those seedlings
; placed in the agar compositions comprising an active ingre-
dient compound had continued to grow horizontally i.e.
t ~ r normal geotropic response had been destroyed. The
untreated plants had exhibited a normal response i.e. their
, root tips had turned downwards.
Table VI
,.. .. .. _ _. ., .. . _
Active Ingrediènt Compound Concentration
(M x 10-6)
3-[o-carboxyphenyl]-5-phenyl-1~2~4-triazole 1
3-phenyl-5-to-carboxyphenyl]-1,2,4-oxadiazole 0.1
5-lo-carboxyphenyl]-3-phenylisoxazole
. ' .. '-".'.'"'''
.. ~ ,.' ~ ' .
,. . .
f -
- 16 -
, '
,
....
,, : .:.... .: . .
66708
EXAMPLE 5
This Example lllustrates the method of the
invention in modlfylng the growth of the plant species
Arabidopsis thaliana.
An aqueous nutrlent medium comprislng a suitable
small concentration of each of the lngredients potassium
dihydrogen phosphate, potasslum nitrate, calcium nitrate,
and magneslum sulphate was prepared and the pB of this
medium was adjusted to 6Ø A small amount of an acetone
solutlon of each of the compounds listed in Table VII
below was added to an aliquot of the nutrient medlum to
provide the active ingredient concentration shown in this
Table.
Each aliquot was then mixed with sufficient molten
agar to solidify it, and 7 mls of each mixture was
poured into a sterilized test tube which was then plugged
with cotton wool. Each test tube was then seeded with a
single seed of Arabldopsis thaliana. Several test tubes
containing solidified nutrient medium and not comprising
- an active ingredient compound was also seeded.
After standing at 4C for 24 hours all the test
tubes were maintained at 25C, at 65% humidity, and
continuously illuminated at 15 t to 20,000 lux from
fluorescent tubes. Germination of the seeds occurred
within 72 hours and growth was allowed to proceed for 20
days. At the end of this period it was observed that the
pattern of growth of both the foliage and roots of those
plants grown in the agar compositions comprising an active
-17-
, - :, ; ~ '' " ~ .
. " ., .' -' ' ' '' ,: .,: ~,.
.. . . . . . . . . . .
''' "; ~ ' ' .. : .:
.
. . . . .. . .
, ", :, , '
1066708
compound was markedly different from that of the untreated
plants.
Table VII
Active Ingredient Compound Concentration
(ppm)
. .
,~ 5-(o-carboxyphenyl)-3-phenylisoxazole 0.1
2-(o-carboxyphenyl)-5-phenyl-1,3,4-oxadiazole 0.5
3-(o-carboxyphenyl)-5-phenyl-1,2,4-triazole 4.0
~-phenyl-5-(o-carboxyphenyl-1,2,4-oxadiazole 1.0
Example 6
A dilute aqueous emulsion of each of the compounds
; listed in Table VII was sprayed onto separate plots of soil
` at a rate equivalent to 1 to 8 kg/ha of active ingredient
and a volume equivalent to 1000 litres per hectare. Seeds
of peas, mustard, barley, maize, linseed, and ryegrass
,,r~ were then sown in each plot and allowed to germinate and
mature. Each species of plant in each plot exhibited plant
~ growth regulatory effects in the form of either leaf``~ 20 epinasty, anti-geotropic root growth, or loss of apical
dominance.
Example 7 ---
This Example illustrates the plant growth regu-
' lating activity of compositions of the invention when applied
to s variety of plant species in both the pre- snd post-
.-: .
'.
- 18 - -
, -
. ~, . . , , , - .
: ................................. -,, , . , , , :.
`` 1066708
-emergent manner.
Seeds of wheat,wild oats, ryegrass, Japanese
millet, peas, ipomoea, mustard and sunflower were
sprinkled onto the surface of soil in separate boxes
and covered with a thin layer of sand. The contents of
each box werethen sprayed with a dilute aqueous
composition comprising one of the compounds listed in
Table VIII and at one of the application rates indicated
thereln r
The contents of the boxes were then lightly watered
wlth an overhead spray and placed ln a glass-house to
encourage germination of the seeds. Three weeks later
the boxes were removed from the glass-house and the
growth pattern of emerged plants was compared to that of
a set of untreated control plants to assess the pre-
emergent plant growth regulating activity of the
compositions applied. The results are presented in Table
VIII.
In addition,seeds of whea~ wild oats, ryegrass,
Japanese millet, peas, ipomoea, mustard, and sunflower were
covered with sand, lightly watered in the manner described
above, and then placed in a glass-house for one week to -
permit germination of the seeds and plant growth to a
height of 4 to 5 inches. The boxes were then removed from
the glass-house and the contents of each box weresprayed
with a dilute aqueous composition comprising as active
ingredient one of the compounds listed in Table VIII and
at one of the application rates indicated therein.
--19--
. ,,' ~, .," ' . ', ;;''.' ' . '
... .
,. . . , -; "
- ~ 1066708
After spraying the boxes Were returned to the
glass-house for a further 3 weeks. The growth pattern
of the plants was then compared with that of a set of
untreated plants to assess the post-emergent plant growth
regulating activity of the compositions applied. The
results are presented in Table VIII.
TABLE VIII
_
Actlve Ingredient Plant - Plant Growth Pattern*
Compound Species Pre-emergence Post-ëmergence
at appllcation at application
.~ _rate * 10 rate o~: 10
. wheatSt ep0 Sl St
: Watds 0 epSl St Sl St
ryegrass epep 0 Sl St
3-(o-carboxy- Japanese ep ep St St
phenyl)-5-phenyl millet
: -1,2,4-triazole
: peasSv St St 0 0
. ipomoea St Sv St St St
mustard St Sv St St 0
Sunflower Sv St Sv St Sl St St
._
wheatSt S1 St 0 0
wild 0 Sl St 0 0
3-phenyl-5- ~- oats
carboxypheny~ -
.~ 1,2,4-oxadiazole ryegrass St St _ 0
_ _ _ millet St St _ St
.
'
-20-
~, , , : ::
: ,. , : , ,, :
' ' '' ' , ' ' ~'' ' ;: ~ . ,
1066708
TA~LE VIII continued
Actlve Ingredient Plant Plant Growth Pattern*
Compound Specles I _
Pre-emergence Post-emergence
at application at application
rate ** of: rate of:
~ -5 10 10
PeasSv St Sv St O O
ipomoead Sv St St St
mustardd Sv St St St
sunflower~ Sv St ¦ Sv St ¦ S
* Plant growth pattern compared to control set of untreated
plants:
S1 St = slightly stunted
St = stunted
Sv St = severely stunted
ep = leaf epinasty
O = substantially unaffected
d = plant died
` - = no test was performed at this concentration.
, 10 ** Kilograms per hectare of active ingredient compound.
EXAMPLE 8
This Example illustrates the use of compositions of
the ~vention in regulating the growth of two species of
grass.
Seeds of Wimmera ryegrass and cocksfoot were sprinkled
onto the surface of soil in separate boxes and covered with
.,
-21-
., ., : . ,., .. ~ ; . . :
.. .. . . .. . .
. .
. ., ~ , . ,, -
" , ., ~ . ~; :
, : . ; ~ , . ::
. .
- - 1066708
a thln layer of sand, lightl~ watered and then placed in
a glass-house to germinate and grow When the plants were
approximately 10 cm high, a box of each specles was
sprayed with a volume of a dilute aqueous emulsion of one
of the active ingredient compounds listed in Table IX
e~uivalent to 1000 litres per hectare and at the application
rate indicated therein. The plants were then returned to
the glass-house and after a period of twenty days their
growth was compared to that of an untreated set of control
plants. The results are presented in Table IX.
TABLE IX
:. _ _ . _
Active Ingredlent Application Reduction in height of
Compound Ratecompared to control
(kg/ha) plants
_ ,
WimmeraCocksfoot
ryegrass
3-lo-carboxypheny~ 1 19 12
-5-phenyl-1,2,4- 5 24 8
triazole ~
3-phenyl-5-~o- 1 19 8
carboxypheny~ - 5 19 8
- 1,2,4-oxadiazole
2-.(o-carboxyphenyl 1 10 16
-5-phenyl-1,3,4- 5 24 28
oxadiazole
.
EXAMPLE 9
Certaln of the compounds of formula (I) were tested
on various plants, e.g. chrysanthemums, Brussels sprout
and soybean for growth regulating properties. The results
-22-
, ,. ~ . , . . . - - . .-. .
.
- . : . , . . , , .. ,. : .
- : :,
. . , : , . ~ . .
. , , - , , ' :' ' '
,, ., ~ , , .
~066708
are shown in Tables X - XI; the compounds tested were
3-phenyl-5-(o-carboxyphenyl) isoxazole (Compound A),
2-(o-carboxyphenyl)-5-phenyl-1,3~4-oxadiazole (Compound
3~(o-car~oxyphenyl~-5-phenyl-1,2,4-tria~ole (Compound C)
and 3 phenyl-5-(o-carboxyphenyl,1,2~4-oxadiazole (Compound
D).
TABLE X
. . ~ ,~ .... _ ......... _
Compound Rate %Growth Reduction (52 days)
kg/ha
Chrysanthemums Brussels Soy-
. sprout bean
-........................... .
D 5 -1 22 s 73 s
D 2 _16 1 s 68 s
A 5 -4 26 s 80 s
A 2 -10 7 58 s
B 5 -27 -9 s 80 s
3 1 2 -13 -3 s 1 88 s
S = side shoots
:
.:In nearly all cases,compounds A and D caused side
shoots on Brussels sprouts and soybean. However whilst
;Brussels sprouts were only stunted by these two compounds
at the higher rate, soybean proved very sensitive to all
`~10 of compounds A, B and D at both high and low rates giving
~short green plants with some leaf curl.
. . .
-23-
. : ; ;~
. . . ~ .
, ~ , . ~, : . .
' : : ,`` . . .
.
---- 1066708
Both compounds A and B caused marked stunting of
Italian rye grass (Lolium multiflorum)with a certain
amount of leaf scorch; the results are shown in Table
XI.
- TABLE XI
,
, r _
Compound Rate % reduction in growth compared
kg/ha with untreated grass
.~ . . ~
First Assessment Second Assessment
: _ (9) (29)
D 5 12 - 40
D 2 11 33
A 5 244 82
C 5 15 49
` C 2 17 54
.. _ _ . . . _ . .__ .,
.
Assessments were made by ta~ing fresh weights of cut grass
. 5 (g). Figures in brackets de~ote time of assessment as days
: after spraying.
,
s Compound C as sprayed onto plants grown in 10 cm pots
at about the 4th leaf stage, at a rate of 5 kg/ha (1000 l/ha).
The results are shown in Table XII.
.
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.
.
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, ~ . : ., ... ; :., , ~ . :
1066~08
TABLE XII
.
.: . - .......... - . ........... _ ,
CompoundPercent growth reduction compared with
untreated plants
Tomato Brussels Soyabean
Sprout
Int. Final Int. Final Int. Final
-36* -35- 10 -12 56- 67*
*epinasty. Negatlve figures are growth increases compared
with check plants,
EXAMPLE 10
Plots measurlng 2 x 2 metres were marked out on a
short sward of St. Augustine grass in the field in the
U.S.A. Sprays of 5,60 ! 2,24 or 1.12 kg/hectar~
; of Compound D were applied to the grass on respective
; plots. There were two replicate plots for each treatment
'~ and two untreated control areas.
- Phytotoxicity of the chemical sprays was assessed 6
and 13 days after treatment and 14 days after treatment,
the plots were cut and the grass weighed. Results in
Table XIII below show that Compound D retarded the growth
of the grass while inducing only neglible damage.
.
i
~ -25-
.
,
... . .
.. .. .
.. . . . ...
,,, ~,, . ; . .
~066708
TABLE XIII
~ . . _ , __ _ . .
Compound D Percent Phytotoxlcity Fresh Wt(g)
Rate _
kg/hectare 6 DAT 13 DAT 14 DAT
I .
5.60 1,5 1.5 825
2~24 2 0.5 605
1.12 O O 1190
O O O 1 995
(DAT = days after treatment)
EXAMPLE 11
Plots 2 rows (approx. 1.2 m wide) and 15 m. in length
were marked out in a crop of an indeterminate variety of
soyabean growing the the field in the U.S.A. and were
sprayed when 10 per cent of the plants were in flower with
Compound D at rates equivalent to 4.~8, 2.24 or
;- 1.12 kg/hectare. Other plots were retained untreated as
controls. There were two replicates of each treatment.
Aqueous suspensions of Compound D were prepared by
diluting an appropriate volume of the miscible liquid
composition of Example 20 below with a solution of 0.05
per cent Agral 90 and were sprayed in a volume equivalent
` to 300 litres/hectare.
The average height of plants in each treatment was
-; 15 determined at intervals after spraying by measuring 10
plants at random in each plot. As will be seen from Table
XIV below, the treated soyabean plan~s were markedly
-26-
- , , .. . . . : . .. ..
. .,: . - , - .. . ... . . . .. .
,. . .. ~ .. .. .
.. . , .. . . . . . . . ~ . . ., .: . ~ , .. :
,, ::, . : . .; . -.:
. . , . ,, :
... ,, ... .. ~ , .
1066708
shortened b~ the Compound D spr~s and this growth
retardation resulted in a complete absence of lodglng
which was present ln the controls and in other plants
in the surrounding field. The beans in each plot were
picked and weighed 90 days after treatment. The average
weight of bean found in each treatment is shown in the
Table and indicates that at only 4.48 kg/hectare of
Compound D was there a yleld decreàse. At 2.24 and 1.12
kg/hectare, Compound D increased bean yields.
TABLE XIV
. ._ ,. _
Compound DMean Plant height Final mean bean yield
Rate lb/acre (cm) (kg)/plot (adjusted
to zero percent
. 11 DAT 18DAT 27DAT moisture).
4 46 56 60 5.25
2 48 60 69 6.65
1 49 62 74 7.25
0 (CoAtrol)-70 87 94 6.50 _
. . .
DAT = days after treatment
EXAMPLE 12
The following Example illustrates the stimulation of
plant growth by a compound of the invention.
Seedlings of grapevine were grown singly in 10 cm
diameter pots containing compost. When they had a stem
--27--
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.
.
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1066708
length of approximately 5 cm, they were sprayed with
Compound A at rates equivalent to 5 and lO kg/ha in a
volume equivalent to 1000 l/ha of an aqueous solution
of O.l per cent Agral 90. Other seedling plants were
left untreated as controls. There were 8 replicate
plants per treatment.
The length of the stem of each plant was measured
from compost level to apex, immediately prior to spraying
and at 13 and 19 days after treatment and the number of
leaves per plant was counted after 29 days. The results
are shown ln Table XV.
',
;
.
'
. . .
-28- .
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,
1066708
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o
h
~O~
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r4 ~
~4
_~
~ U~ ~ ~
~ C~ 1~ ~ ~1
: ~~ a~
~ . '
~' ~ ~ ~ ~ O
.. ; ~ _ _~ _l _l
..___
~ S ~ u~
~:~. ~ ~ ~ _
O ~ o~
,~ ~ ,~ ~ ~1
' ~ ~
,. C~
~' O U~
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,.' ~ ~ O
~ 0~1 50
." ,a ~0 ~ u~ O
. ~ O - . ,
:~ ~ ~ .`
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-` 1066708
Although there is a slight tendency for an
increased rate of leaf production after plant were
sprayed with Compound A, the marked stimulations of
growth were accounted for by a more rapid rate of
internode extension.
EXAMPLE 12A
2-(o-carboxyphenyl)-5-phenyl-1,3,4-thiadiazole
(Compound E), 2-(o-carboxyphenyl)-5-(0-chlorophenyl)-
1,3,4-thiadlazole (Compound F) and 2-(o-carbox~phenyl)-
5-(~-chloropehnyl)-1,3,4-thiadlazole (Compound G) were
tested in varlous plants.
The plants were grown in 7.5 cm pots and sprayed
at approxlmately the 2~ leaf stage for the tomato, Brussels
; sprout and soyabean plants, and 11 days after sowing for
the cereal. Sprays were at 5 kg/ha (1000 l/ha) of the
compounds and the plants were assessed visually 9 days
after treatment.
`':
-. , l
COMPOUNDP ~RCENTAGE REDUCTII ~N IN GROW rH
Wheat Barley Timothy Tomato Brussels Soya-
` grass sprout bean --
E 15 15 15 0* 20 70*
F O 15 O 0* 30 50*
G 60 15 O 80 50* 50
i
*leaf curling and stem twisting
The results show that the compound have plant growth
retardant activity.
-30-
.
:. , '. ',, ' . ::
1066708
EXAMPLE 13
This Example describes the preparation of 3-phenyl-
5-to-carboxyphenyl)isoxazole (Compound A) according to
the equations:
~C CH2-11 ~ 2
C02H
C-C~2-C~
02H
heat
.C\,~ , rC
,
-31-
- ,
,. " ,
,: . ', " - - ': , ,:
'- ' ' , , . , '', .,
" --` 1066708
l-o-carboxyphenyl-3-phenylpropane-1,3-dione (1.4 g)
was dissolved in glacial acid (20 ml) and hydroxylamine
hydrochloride (0.5 gm) and sodium acetate (1.0 gm) added.
The mixture was boiled under reflux ~or 2 hours. The
yellow solution was poured into water (100 ml) and the
precipitated solid was collected by filtration and then
crystallised from aqueous ethanol to yield 1.1 g of the
product as yellow plates, m.p. 193-195C.
:.
EXAMPLE 14
This Example illustrates another wa~, which i5 in
fact preferred, for preparing Compound A.
2-Carboxybenzaldehyde (15 g) and acetophenone (12 g)
were dissolved in ethanol (60 ml). A solution of sodium
hudroxide (8 g) in water (40 ml) was added and the mixture
~stirred at room temperature for 4-6 hours. The mixture
was then poured into water (500-600 ml) and the solution
.` acidified. The oily product slowly solidified and was -
`` collected and crystallized from ethanol td give
o~-phenacyl phthalide as colourless needles, m.p. 143-145.
Yield 21-23 g (88-92%).
0~-Phenacyl phthalide (5 g) was suspended in dry benzene
(75 ml) and the mlxture stirred and bo'led under reflux~
Bron~ne~ ml) was added dropwise over 15 min to:~he solution,
and stirring and refluxing were continued for 1 hr. The
25 solution was then filtered and the benzene removed in vacuo. -
The crude bromo compound was suspended in ethanol (50 ml)
and hydroxylamine hydrochloride (4.2 g) and anhydrous sodium
acetate (8.2 g) added and the mixture boiled under reflux
-32-
`` 1066708
for 2 hours. About half the ethanol was xemoved in
vacuo, and 5~ sodi~m bicarbonate solution (200 ml) added.
The mixture was then filtered through Celite, and the
filtrate acidified with conc. hydrochloric acid. The
crude product was filtered off and recrystallized from aqueous
ethanol to glve the isoxazole (2.7 g, 51~) as fine
buff-coloured plates, m.p. 190-193.
EXAMPLE 15
Benzoyl hydrazide (6,8 g) (from ethyl benzoate and
hydrazine hydrate - see below) was dissolved in glacial
acetlc acid (30 ml) and added to 2-carboxybenzaldehyde
(7,5 g) in glacial acetic acid (50 ml). The mixture was
warmed briefly and allowed to stand at room temperature
for 30 mins, during which time the product crystallized.
It was filtered and washed with glacial acetic acid-
lS -petroleum ether (1:2) and dried. The hydrazone ~12.6 g,
94%) was obtained as a colourless powder, m.p. 201-203.
The hydrazone (5.4 g) was suspended in glacial acetic
acid (75 mlj and finely-powdered anhydrous sodium acetate I -
; (8.0 g) was-added. Then bromine ( 1 ml) in glacial ¦ -
acetic acid (10 ml) was added to the rapidly-stirred
mixture. After stirring for about 5 mins, the brick-red
precipitate was removed by filtration. The precipitate
was then suspended in glacial acetic acid (40-50 ml) and
the mixture boiled. The solid mhterial gradually dissoived
and the solution became pale orange. After 10-li mins, the ~ ¦
volume had been reduced to about 25 ml, and then wa~er was
added slowly until crystallization o~ the product commenced.
I ' .
-33-
~ ;
1066708
Cooling gave 2-(o~carboxyphenyl)-5~phenyl-1,3,4~
-oxadiazole (3.6 g, 70%) as colourless plates, m.p.
178-180. The product may be purified further by re-
crystallization from aqueous ethanol.
The hydraz~de starting material can be made as
follows. Ethyl benzoate` (40 g) and hydrazine hydrate
(50 ml) were refluxed gently for 5-6 hrs. On cooling,
the react~on mixture solidified and the solid material
was crystallized from water to give the hydrazide (33 g,
90~) as fine, buff-coloured needles, m.p. 122-124.
EXAMPLE 16
This Example illustrates the preparation of
3-[o-carboxyphenyl]-S-phenyl-1,2,4-triazole according to
the equations
~ ~N~-NN2 ~ CN ~ )
.. ..
-
`. ~ / .
- 4 /
.~ ~C02H ~
-- ` .
.
`
. ' ' ' `
,
i ' ' - .... .. .. . .
.
- 1066708
o-Toluhydrazide (20 g) and benzonitrile (150 ml)
were treated ln an autoclave at 250 for 3 hrs. The
contents were allowed to cool, diluted with ether t200 ml)
and extracted with 5~ NaOH (3 x SO ml). The combined
alkaline extracts were washed with ether (2 x 50 ml)and
brought to pH 5 with 10% HCl. 3-o-Tolyl-5-phenyl-1,2,4_
triazole precipitated as a gummy solid (18 g, 57~) which
was used without purification in the next step.
The o-tolyl-triazole (crude product, 18 g) was
dissolved in 10% NaOH (300 ml) and KMnO4 (45 g) added.
The mixture was s~i~rred under reflux or 1 hr, filtered
through Celite and acidified with conc.HCl. The crude
product which precipitated was boiled with ethanol (100 ml)
for 10 min, chilled and collected to give 3-o-carboxyphenyl- ¦
5-phenyl-1,2,4-triazole was obtained as a white
microcrystalline powder (10 g, 50%)~ mp 237-239. !-
EXAMPLE 17
o-Carboxyacetophenone (14.7 g) was dissolved in dry '
benzene (100 ml) and treated with bromine (4 5 ml). After
the addition o~ the first few drops of bromine, the flask
was warmed to initiate the reaction. When the solution had ~ '
~eco~e decolourized, the remaining bromine was added rapidly
dropwise, with stirring. Stirring was continued for 5 mins
after the addition was complete, then the solvent was ~
removed in vacuo. The syrupy residue crystallised on trituration
-''with light'petrole~m (boiling range 60-80) and the crude -
o-carboxyphenacyl bromide (quantitati~e yield, m.p. 127-128)
was used dlrectly in the next step. ' '-
.: " . .'
-35-
1~
", ", . . ..
1066708
A solution of thiobenzamide (1.45 g) and
_-carboxyphenacyl bromide (2.45 g) in ethanol (50 ml)
was refluxed for 24 hrs. The solvent was removed in
vacuo and the product recrystallised from aqueous ethanol
to give 2-phenyl-4- (o-ethoxycarbonylphenyl)-thiazole
(2.2S g, 73%) as colourless needles, m.p. 77-79. The
ethyl ester (4.5 g) was heated under relux for 1 hr in
ethanol (50 ml) containing 10% sodium hydroxide solution
(10 ml). The mixture was then poured into water (200 ml)
and acidified with 10% hydrochloric acid. On chilling,
` the product, i.e. 2-phenyl-4-(o-carboxyphenyl)-thiazole,
crystallised as fine needles (4.1 g), m.p. 159-161.
EXAMPLE 18
This Example illustrates a composition according to
the invention in the form of an emulslfiable concentrate
formulation, suitable for dilution with water.
Weight %
`~ 3-Phenyl-S-(o-carboxyphenyl)-1,2,4~oxadiazole 20
Condensate of 2 moles ethylene oxide with a
; mixture of oleyl a~d cetyl alcohols 5
Mixture of calcium dodecyl benzene sulphonate
with ethoxylated castor oil S
Technical grade methylcyclohexanone 70
100~ ,
-36-
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, ' ' ' ` ' ', ' ' ` ','' '; ," ~
.. . . . . . .
`--` 1066708
EXAMPLE 19
This Example illustrates a solid composition
according to the invention suitable for application in
the form of granules.
Weight
2-(o carboxyphenyl)-5~phenyl-1,3,4-
oxadiazole 3
Pumice granules 97
100
EXAMPLE 20
This Example illustrates a miscible liquid composition.
Weight
3-Phenyl-5-(o-carboxyphenyl)-1,2,4-
oxadiazole 20
Triethanolamine 12.2
Isopropanol 20
Water to 100
R~P/SG 37
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