Note: Descriptions are shown in the official language in which they were submitted.
THIS INVENTION relates to new derivatives of
1,2,4-oxadiazin-5-one and to processes for their
preparation.
The new derivatives of 1,2,4-oxadiazin-5-one of
the present invention are those compounds of the general
formula:
R
O~ N
~ ~ Ar
wherein R represents a hydrogen atom or an alkyl radical
~ containing 1 to 4 carbon atoms, or a phenyl radical, and
: 10 Ar represents a phenyl radical substituted by 1, 2 or 3
substituents, which - when two or three substituents are
present - may be identical or different, selected from
halogen atoms, the hydroxy radical, alkyl radicals
containing 1 to 4 carbon atoms, alkoxy radicals containing
1 to 4 carbon atoms, alkylthio radicals containing 1 to 4
carbon atoms, alkylsulphonyl radicals containing 1 to 4
carbon atoms, the trifluoromethylthio radical, the nitro radical,
dialkylamino radicals containing 1 to 4 carbon atoms in
.,~
o~
each alkyl group, the sulphamoyl radical and
dialkylsulphamoyl radicals containing 1 to 4 carbon atoms
in each alkyl group, or Ar represents a thienyl, pyrrolyl
or furyl radical unsubstit~lted or substituted by a halogen
atom or an alkyl radical containing 1 to 4 carbon
atoms.
Preferred compounds of the invention are those
1,2,4-oxadiazin-5-ones of general formula I wherein
R represents a hydrogen atom or a methyl or phenyl
radical, and Ar represents the phenyl radical substituted
by 1, 2 ox 3 substituents selected from halogen atoms and
methyl, hydroxy, methoxy, methylthio, methylsulphonyl,
trifluoromethylthio, nitro, dimethylamino, sulphamoyl
and dimethylsulphamoyl radicals, or Ar represents a
thienyl, pyrrolyl or furyl radical unsubstituted or
substituted by a halogen atom or the methyl radical.
.. j, .
,~ .
~0'3Z~D~
Of outstanding importance are those l,2,4-
oxadiazin-S-one derivatives of general formula I wherein
Ar is a thienyl radical optionally substituted by a halogen
atom or an alkyl radical containing 1 to 4 carbon atom~,
for example 3-(5~chlorothien 2-yl)-5,6-dihydro 4H-1,2,4-
oxadiazin-5-one, 3-(thien-2 yl)-5,6-dihydro-4H,l,2,4-
oxadiazin-5-one, 6-methyl-3-(thien-2-yl)-5,6-dihydro-4H-
1,2,4-oxadiazin-5~one, 3-(thien-3-yl)-5,6-dihydro-4H-1,2,4-
oxadiazin-5-one, 3-(5-methylthien-2-yl)-5,6-dihydro-4H-1,2,4-
oxadiazin-5-one, 3-(3-methylthien-2-yl)-5,6-dihydro-4H-1,2,4-
oxadiazin-5-one, 3-(3-bromothien-2-yl)-5,6-dihydro-4H-1,2,4-
oxadiazin-5-one, 6-ethyl-3-~thien-2-yl)-5,6-dihydro-4H-1,2,4-
oxadiazin-5-one, and 6-phenyl-3-(thien-2-yl)-5,6-dihydro-4H-
1,2,4-oxadiazin-5-one.
; lS According to a feature of the present invention,
; the compounds of general formula I are prepared by the
process which comprises cyclising an amidoxime derivative
of the general formula:
-- 4 --
~ . . , ~ .,
.~i~- ~
~ s~,
10~2~
R
OCH - COOR1
. Ar - \ . II
- NH2
wherein Ar and R are as hereinbefore defined, and Rl
represents an alkyl radical containing 1 to 4 carbon
atoms.
Generally the cyclisation is carried out by
¦ heating the amidoxime derivative in a basic medium at
¦ temperature between 20 and 70C. It is particularly
¦ advantageous to work in an organic solvent, such as pyridine
or in an alcohol such as ethanol, in the presence of an alkali
metal alkoxide such as sodium methoxide or sodium ethoxide.
The amidoxime derivatives of general fonnula II
can be obtained in accordance with one of the following
methods~
(1) By the reaction oE an a-halogeno-ester of the
general formula:
Y - CH - COORl III
. . R
(wherein R and Rl are as hereinbefore defined, and Y
represents a halogen atom) with an amidoxime of the general
formula: .
'
-- 5 --
2.11L0~9
~ N ~ OH
Ar - C~ IV
~2
wherein Ar is as hereinbefore defined. The reaction is
genera]ly carried out in an aqueous organic solvent, such
as a mixture of ethanol and ~ater or dimethylforrnamide
and water, in the presence of an alkaline condensation
agent, such as sodium hydroxide, potassium hydroxide or a
tetraal];ylammonium hydroxide, and at a temperature between
20 and 80C. In certain cases, this reaction makes it
possible to obtain directly the cyclised compound of
general formula I without going through the intermediate
compound of general formula II.
The amidoximes of general formula IV can be
obtained by the action of hydroxylamine on a nitrile of the
general formula:
1~ Ar - C~ V
wherein Ar is as hereinbefore defined. The reaction is
generally carried out in an aqueous organic solvent, such
as aqueous ethanol, at a temperature getween 20 and 80C.
(2) By the reaction of an ~-aminoxy-ester of the
general formula-
' ,
H2N - o - CE - COORl VI
~wherein R and Rl are as hereinbefore defined) or an acid
-- 6 --
3Z1L~
.
addition salt, e.g. hydrochloride, thereof, with an
imino-ether salt of the general formula:
Ar - C \ . HA VII
- C2~5
wherein Ar is as hereinbefore defined and HA represents a
molecule of hydrogen chloride (HCl) or of fiuoboric acid
(HBF~). The reaction is generally carried out in a basic
oxganic solvent, such as pyr.idine, at a temperature between
15 and 35C.
The imino-ether salt of general formula VII can
be obtained by the action of a solution of hydrogen chloride
in ethanol on a nitrile of general formula V, or by the
action of triethyloxonium fluoborate ~eerweinsalt) on an
amide of the general formula:
Ar - CO~H2 VIII
.wherein Ar is as hereinbefore defined.
(3) By the reaction of a compound of the general formula:
R
- 0 ~ CH - COCl
Ar - C~ IX
\ ~H2 HCl
(wherein R and Ar are as hereinbefore defined) with an
alcohol of the general formula: .
RlOH X
109210'.r3
wherein Rl is a~ hereinbefore defined. The reaction is
carried out by heating the compounc1 of yeneral formula IX
in the presence of the alcohol of general formula X at a
temperature between 50C and the boiling point of the
alcohol.
According to another feature of the invention,
the compounds of general formula I are prepared by the
reaction of an a-amino~y-ester of general fonnula VI with
I an imino-ether salt of general formula VII in a basic organic
i 10 solvent, such as pyridine, at a temperature between 80 and 120C.
According to a still further feature of the
invention, the co~pounds of general fonmula I are prepared
by the process which comprises treating a compound of
the general formula:
x I ~o~N XI
¦ wherein R and Ar are as hereinbefore defined and X represents a
halogen (preferably chlorine or bromine) atom, with an alkali
metal hydroxi*e in an aqueous solution at a temperature between
15 and 35C.
The compounds of general formula XI can be obtained
by the action of an acid chloride of the general formula:
X - CH - CGCl
R XII
.
-- 8 --
3Z~
(wherein R and X are as hereinbe~ore defined) with an
amidoxime of general formula IV.
The reaction is generally carried out in an
organic solvent, such as dioxan or toluene, in the presence
of pyridine.
The compounds of general formula-I obtained by
the aforedescribed processes can optionally be purified
by physico-chemical methods such as crystallisation or
chromatography.
The 1,2,4-oxadiazin-5-one derivatives of the
present invention exhibit remarkable properties which
render th~m particularly useful in the agricultural field.
¦ The following Examples illustrate the preparationof 1,2,4-oxadiazin-5-one derivatives of general formula I
by processes hereinbefore described.
~XAMPLE 1
A mixture of ethyl 4-chlorobenzimidate hydrochloride
(47.8 g), ethyl aminooxyacetate hydrochloride (34 g) and
anhydrolls pyridine (~20 cc) is heated at the boiling p~int,
~0 whilst stirring, for 16 hours. The pyridine is then
evaporated under reduced pressure (20 mmHg) and the
concentrate is taken up with ethyl acetate (600 cc) and
water (300 cc). The organic phase is decanted and then
washed with water (3 x 100 cc). After drying over anhydrous
sodium sulphate, the solvent is evaporated under reduced
_ . . ,._ .. . .
~Z~L09
pressure (20 mm~Ig). The solid res:idue is taken up in
diisopropyl ether (100 cc) and the crystals are filkexed
off. 3-(4-Chlorophenyl)--5,6-dihydro-4H-1,2,4-oxadiazin-5-
one (24.1 g) is thus obtained. After recrystallisation
from ethanol (7 parts by volume), the p~oduct melts at
170C
Ethyl 4-chlorobenzimidate hydrochloride, used as
starting material, can be prepared by the method of
L. Weintraub, 5.R. Oles and N. Kalish, J. Org. Chem. 33,
7,679 (1963).
EXAMPLE 2
Following the procedure of Example 1, but starting
with ethyl 2-chlorobenzimidate hydrochloride and ethyl
aminoxyacetate hydrochloride, 3-(2-chlorophenyl)-5,6-
dihydro~4H-1,2,4-oxadiazin-5-one, melting at 132C, is
¦ obtained in a yield of 80%.
Il By proceeding as described in Example 1 but using
I appropriate starting materials of general formulae VI and
I VII there were obtained the following products having the
stated melting points aftex recrystallisation.
EXAMPLE 3
3-(4-Hydroxyphenyl)-5,6-dihydro-4H-1,2,4-
oxadiazin-5-one, m.p. 251C (yicld 66%).
- EXAMPLE 4
3-(4-Methoxyphenyl)-5,6-dihydro-4H-1,2,4-
oxadiazin-5-one, m.p. 212C (yield 63%).
-- 10 --
.
.
EXAMPLE 5
3-(2,4 Dichlorophenyl)-5,6-dihydro-4H-1,2,4-
oxadiazin-5-one, m.p. 179C (yield 58%).
EX~MPLE 6
3-[3~(Methy]thio)phenyl]-5,6-dihydro~4H-1,2,4-
oxadiazin-5~one, m.p. 128C (yield 67%~.
EXAMPLE 7
0-Ethoxycarbonylmethyl-5-chlorothiophene-2-
car~oxamidoxime (14.1 g) and dry sodium methoxide (2.9 g)
in ethanol (140 cc3 are stirxed at ambient temperature for
3 hours. The ethanol is then evaporated under reduced
pressure and the solid residue is taken up in distilled
water (100 cc). The solution thus obtained is acidified
by adding ~ hydrochloric acid t54 cc). The white crystals
which are forned are filtered off and washed with water.
After drying, 3-(5-chlo~othien-2-yl)-5,6-dihydro-4H-1,2,4-
oxadiazin-5-one (10.7 g), melting at 210C, is ob-tained.
By proceeding as described in Example 7 but using
appropriate starting materials of g~neral formula II, there
were obtained the follo~ing products having the stated
melting points.
EXAMPLE 8
3-(Thien-2-yl)-5,6-dihydro-4H-1,2,4~oxadiazin-5-
~ne, m.p. 180C (yield 72%).
EXAMPLE 9
6-Methyl-3-(thien-2-yl)-5,6-dihydro-4H-1,2,4-
f~
oxadiaz:;n-5-one, m.p. 187C (yield 87%).
EXAMPLE lO
,
3-(Thien-3-yl)-5,6-dihydro-4H-1,2,4-oxadiazin-5-
one, m.p. 183C (yield 96%)-.
EY~MPLE 11
3-(Fur-2-yl)-5,6-dihydro-4H-1,2,4-oxadiazin-5-
one, m.p. 186C (yield 77%).
EX~MPEE 12
3-(5-Methylthien-2-yl)-5,6-dihydro-4H-1,2,4-
oxadiazin-5-one, m.p. 215C (yield 92%)~
EXAMPLE 13
3-tN-Methylpyrrol-2 yl) 5,6-dihydro-4H-1,2,4--
oxadiazin-5-one, m.p. 143C (yield 69%).
EXAMPLE 14
3-(Pyrrol-2-yl)-5,6-dihydro-4H-1,2,4-oxadiazin-
S-one, m.p. 261C (yield 91%).
EXAMPLE 15
.
3-(3-Methylthien-2-yl)-5,6-dihydro-4H-1,2,4-
oxadiazin-5-one, m.p. 100C (yield 89%).
EXAMPLE 16
3-(3-Bromothien-2-yl)-5,6-dihydro-4H-1,2,4-
oxadiazin-5-one, m.p. 127C (yield 89%)~
EXAMPLE 17
3-(4-Dimethylaminophenyl)-5,6-dihydro-4H-1,2,4~
oxadiazin-5-one, m.p. 210C (yield 81%).
,
- 12 -
.. ~ _ .... . .
~2~
E~MPL3 18
3-(3-Nitrophenyl)-5,6-dihydro~4H-1,2,4-oxadiaæin-
5-one, m.p. 210C (yield 90%).
EX~MPLE 19
3-(2-Iodophenyl)-5,6-dihydro-4H-1,2,4-oxadiazin-
5-one, m.p. 146C (yield 84%).
EXAMPLE 20
3-(3-Hydroxyphenyl)-5,6~dihydro-4H-1,2,4-oxadiazin-
5-one, m.p. 184C (yield 73%).
EXAMPLE 21
3-(3-Chlorophenyl)-5,6-dihydro-4H-1,2,4-oxadiazin-
5-one' m.p. 130C (yield 81%).
EXAMPLE 22
3-(4-Chloro-3-nitrophenyl)-5,6-dihydro-4H-1,2,4-
oxadiazin-5-one, m.p. 203C (yield 68%).
EX ~MPLE 2 3
3-(3-Fluorophenyl)-5,6-dihydro-4H-1,2 4-oxadiazin-
5-one, m.p. 148C (yield 76%).
EXAMPLE 24
3-(2-Fluorophenyl)-5,6-dihydro-4H-1,2,4-oxadiazin-
5-one, m~p. 126C ~yield 71%).
EXAMPLE 25
3-(4-N,M-Dimethylsulphamoylp~enyl)-S,6-dihydro-4H-
1,2,4-oxadiazin-5-one, m~p. l90~C (yield 81%).
~ .
~' ' ' .
-- 13 --
~L0~;21()~3
EXAMPLE 26
3-(3~ -Dimethylsulphamoylpheny~)-5,6-dihydro-
4H-1,2,4-oxadiazin-5-one, m.p. 164C (yield 93%~.
~.XAMPLE 27
3-(3-Sulphamoylphenyl)-5,6-dihydro-4~I-1,2,4-
oxadiazin-5-one, m.p. 205C (yield 64%).
EXAMPLE 28
3-[3-(Trifluoromethylthio)phenyl~-5,6-dlhydro-
4H-1,2,4-oxadiazin-5-one, m.p. 132C (yield 76%).
EXAMPLE 29
I 3-(3-Methylsulphonylphenyl)-5,6-dihydro-4H-1,2,4-
¦ oxadiazin~5-one, m.p. 203C (yield 97%).
EXAMPLE 30
3-(2 Bromophenyl)-5,6-dihydro-4H-1,2,4-oxadiazin-
5-one, m.p. 123DC (yield 77%).
EXhMPLE 31
Chloroacetyl chloride (1.13 g) is added dropwise,
! over the course of 10 mlnutes, to a solution of thiophene-
2-carboxamidoxime (1.42 g) in dioxan (20 cc). The white
precipitate obtained is dissolved by adding pyridine (3 cc)
to the reaction mixture. After 16 hours at a temperature
of about 20C, a brown oil separates out. The solvents
are evaporated at a temperature of about 20C under reduced
pressure ~0 m~Ig followed by 1 mmHg), and the concentrate
is then taken up in water ~10 cc). The precipitate obtained
~l0~JZ~ 3
is filtered off and washed with water (2 x 5 cc). After
drying, 0-chloroacetyl-thiophene-2-carboxamidoxime
(1.1 g), melting at 156C, is obtain~d.
0-Chloroacetyl-thiophene-2-carboxamidoxime (1 g)
is d.issolved in toluene (20 cc) and the solution is heated
under reflux for 16 hours. After decolourising with
charcoal, the solution is concentrated under reduced
pressure (20 m~Ig) and the crystals which are deposited are
dried under reduced pressure ~1 ~Hg) at a temperature of
about 20C. 5-Chloromethyl-3-(thien-2-yl)-1,2,4-oxadiazole
(0.9 g), melting at 57C, is thus obtained.
5-Chloromethyl-3-(thien-2-yl)-1,2,4-oxadiazole
(0.67 g) is dissolved in dimethylformamide (5 cc). A 2N
~ aqueous sodium hydroxide solution (5 cc) is added to the
¦ 15 solution obtained and the mixture is stirred for 30 minutes.
It is then acidified with 11~ hydrochloric acid (0~9 cc)
and the crystals obtained are filtered off and washed with
I water (4 x 10 cc). After drying, 3-tthien-2-yl)-5j6-
dihydro-4~-1,2,4-oxadiazin-5-one (o.46 g), melting at 180C,
is obtained.
- The following Examples illustrate the preparation
of a 1,2,4-oxadiazolin-5-one derivative of general formllia
I by the reaction of compounds of general formula III and IV
without separation of an intermediate amidoxime derivative
~5 of general fo,rmula TI which is formed and is cyclised
- 15 -
,,
2113~
immediately.
EXAMPLE 32
Thiophene~2-carbo~amidoxime (28.4 g) is added
to a 2~ ethanolic sodium hydroxide solution (200 cc),
and a solui-ion of ethyl bromobutyrate in ethanol (200 cc)
is then added over the course of 30 minutes. The reaction
mixture is stirred for 16 hours and the alcohol is then
distilled at a temperature of about 25C under reduced
pressure (20 m~g). The residue obtained is taken up in
water (200 cc) and diethyl ether (100 cc). The organic
phase is decanted and washed with water (100 cc). The
aqueous liquors are combined and acidified with citric acid
(14 g). A precipitate is obtained, which is filtered off
and washed with water (3 x 20 cc) and then dried at a
temperature of about 20C under reduced pressure (1 mmHg).
6-Ethyl-3-(thien-2-yl)-5,6-dihydro-4H-1,2,4-oxadiazin-5-
one ~10.38 g), melting at 171C, is thus obtained. After
recrystallisation from acetonitrile, the pure product
melts at 176C.
~0 EXAMPLE 33
By following the procedure of Example 32 but
starting with thiophene-2-carboxamidoxime (20 g) and ethyl
bromophenylacetate (34.2 g), 6-phenyl-3-(thien-2-yl)-
5,6-dihydro-4H-1,2,4-oxadiazin-5-one (10.3 g), melting at
173C after recrystallisation, is obtained.
- - 16 -
Zl~!~
As mentioned heretofore the 1,2,4-oxadiazin-5-
one derivatives of general formula I possess properties
useful in the ~gricultural field.
When they axe use~ at doses of between 1 and 100
g/hl of water, they exhibit phytohormonal properties. In
that case, they possess auxinic actions analogous to those
of indolylacetic acid or of derivatives of the phenoxyacetic
acidsD They are particularly useful in assisting the se~ting
of fruit on certain plants (tomatoes), preventing the
shedding of leaves or fruit, or increasing the formation of
roots.
When they are used at rates of application of
~etween O.S and 10 kgjha, the 1,2,4-oxadiazin-5-one
derivatives of the present invention exhibit herbicidal
properties, in particular against dicotyledon plants, both in
pre~ emergence and in post-emergence application.
For practical application the 1,2,4-oxadiazin-
5-one derivatives of general formula I are rarely employed
by themselves, but instead are generally employed in
association with at least one carrier and/or a surface-
active agent compatible with the active material and
suitable for use in agricultural or horticultural
compositions. In such compositions the content of active
compound can be from 0.005 to 95% by weight according
to the form of presentation.
The term "carrier" in the sense of the present
~z~
description denotes an organic or inorganic, natural or
synthetic, material with which the active material is
associated in order to facilitate its application to the
plant, to seeds or to the soil, or to facilitate its
S transportation, or its handling. The carrier can be solid
(e.g. clays, natural or synthetic silicates, resins, waxes
and solid fertilisers) or fluid ~e.g. water, alcohols,
ketones, petroleum fractions, chlorinated hydrocarbons or
liquefied gases).
The surface-active agent can be an emulsifying
agent, a dispersing agent or wetting agent, which can be
ionic or non-ionic, for example, salts of polyacrylic acids
and of ligninsulphonic acids, and condensates of ethylene
oxide with fatty alcohols, fatty acids or fatty amines, and
especially products based on condensates of ethylene oxide
such as the condensates of ethylene oxide with the octylphenol
or nonylphenol.
The cornpositions can be prepared in the form of
wettable powders, dusting powders, granules, solutions,
suspensions, emulsifiable concentrates, emulsions,
suspension concentrates and aerosols.
The wettable powders are usually prepared in such
a way that they contain from 20 to 95% by weight of active
compound; they usually contain, in addition to a solid
carrier, from 0 to 5% by weight of wetting agent, from 3 to
- 18 -
, ~ ~ ., .
.. i ,~ .
10~3~
10% by weight of a dispersi.ny agent and, where necessary,
from 0 to 10% by we.iyht of one ox more stabilisers and/or
other adjuvants such as penetrating agents, adhesives or
- anti-caking agents and dyestuffs.
~y way of example, the composition of a wettable
powder is given below, the percelltages being expressed by
weight 7
EXAMPLE 34
Compound of formula I 50%
calcium lignosulphate (deflocculating agent) 5%
isopropyl naphthalenesul~honate (wetting agent) 1%
silica anti-caking agent 5%
ll kaolin filler 39%.
'I . The powders for dusting are usually pr~pared in
the form of a dust concentrate having a composition sirnilar
to tbat of a wettable powder but without dispersing agent,
1. they can be diluted on site by means of a supplementary
I amolmt of a solid carrier so that a composition which usually
contains from 0.5 to 10% ~y weight of active compound is
obtained.
- The emulsifiable concentrates which can be applied
by spraying usually contain, in addition to the solvent and,
where necessary, a co-solvent, from 10 to 50% (w/v) of
active com~,ound, from 2 to 20% (w/v) of emulsifiers and
from 0 to 20% (w/v) of appropriate additives, such as
.. . -- 19 --
. , .
.
__ _
~Z~L0~3
stabilisers, penetrating agents, corrosion inhibitors,
dyestuffs and adhesives.
The suspension concentrates, which can also be
applied by spraying, are prepared in such a way that a
stable fluid product which does not sediment is obtained.
They usually contain frorn 10 to 75% by weight of active
compound, from 0.5 to 15% by weight of surface-active agents,
from 0.1 to 10% by weight of anti-sedimentation agents such
as protective colloids and thixotropic agents, from 0 to 10~/o
by weight of appropriate additives, such as anti-foam agents,
corrosion inhibitors, stabilisers, penetrating agents and
adhesives and, as the carrier, water or an organic liquid
in which the active material is substantially insoluble,
certain organic solid materials or inorganic salts can be
dissolved in the carrier to assist in preventing the
sedimentation or to act as anti-freeze agents for the water.
Aqueous dispersions and emulsions, for example
~ompositions obtained by diluting a wettable powder or an
emulsifiable concentrate as hereinbefore described with
water, are also useful. These emulsions can be of the water-
in-oil type or of the oil-in-water type and can have a
thick consistency such as that of a "mayonnaise".
For a so-called "ultra-low volume" application,
entailing spraying as very fine droplets, solutions in
- 20 -
r~ .
}~ .
~1,9;~
organic solvents, which contain from 70 to 95% of active
compound, are prepared n
The compositions can contain other ingredients,
for example protective colloids, adhesives or thickeners,
thixotropic agents, stabllisers or sequestering agents,
as well as other substances which are known to have pesticidal
properties, in particular insecticides or fungicides.
A further example of an agricultural composition
is given below.
EXAMPLE 35
A condensation product (10 parts~ of ethylene
oxide and octylphenol, having 10 molecules of ethylene
oxide per molecule of octylphenol, is added to a solution
of 3- ( thien-2-yl)-5,6-dihydro-1,2,4-oxadiazin-5-one
(25 parts) in a mixture (65 parts~ of equal parts of toluene
and acetophenone. The solution is used for agricultural
purposes, after dilution with water, at the rate of 100 cc
of solution per 100 litres of water.
The phytohormonal activity of the 1,2,4-oxadiazin-
5-one derivatives of the present invention is demonstrated in
the following experiments.
(1) Settinq of fruit of tomatoes
1 drop (0.05 cc) of the solution or suspension of
th~ compound to be studied is deposited on the ovary of
- 21 -
~, - ..
......
2~
emasculated flowers of tomato plants. After a perlod of
I observation of 15 days, the percentage of fruit forrned
3 relative to the control is noted.
Used in this way, at a concentration of 100 mg/litre,
, 5 the product of Example 8 shows a degree of setting of fruit
of 100%, relative to the control (0%). The fruit formed i5
devoid of pips.
' , (2) Propaqation of tomato leaves
¦ , The 3rd and 4th leaves are taken from tomato stems
(Marmande variety) having 5 to 6 l~aves. l~e petiole of
, ' each leaf is di,pped, over a length of 2 to 3 cm, into the
¦ , ' solution to be studied, contained in a test tube. 8 Days
, after startlng the experiment, the'number of roots fol^med
¦ on the petioles of the treated leaves is counted and their
j 15 aspect is observed.
Used in this wayj at a concentration of 10 mg/litre,
the product of Example 8 causes the formation of 100% of
rooted leaves, whilst the formation is zero in the case of
' ' the petioles of control plants. In the same way, but at a' 20 concentration o* 1 mg/litre, the pro~ucts of Exarnples 9 and 11
,cause the formation of 100% of rooted leaves~ With the
''product of Example 9 the roots are short and thick: with the
product of Example 11 the roots are short,and thin.
22 -
,
1. ' ' , , .
~3~
The herbicidal activity of the comE)ounds of general
formula I is demonstrated i.n the following,manner:
Seeds of various sp0cies, namely wheat (Triticum
sativum), lentil (Lens culinaris), radish tRaphanus
sativus), sugar beet (Beta vulqaris) and slender foxtail
E~S~ aqrestis), are sown in plastic pot,s (180 cc
capacity) containing to a height of 6 cm a mixture composed
of 1/3 of clean earth, 1/3 of vegetable mould and 1/3 of
river sand, at the rate of about 30 seeds psr pot. For each
concentration of compound, two pots of wheat and four pots
ll of the other species are used~
! For the purpose of a post-emergence treatment, the
I sowing is carried out in a greenhouse one week before the
I . start of the experiment so that the small plants are at the
i 15 following stage at the time of treatmsnt:
¦ ' wheat and foxtail : 2 or 3 leaves
lentil : 3 leaves
beet and radish : 2 well-developed cotyledon leaves.
The treatment is carr,~ed out by spraying the
solution or suspension of the product, the pots being placed
on a pot-turner. Each pot is given 1 cc of the solution.
The doses of the product to be studied are 1, 8 and 10 kg/ha.
In pre-emergence testing, the seeded surface of
the pots is ~llowed to dry, then covered to a depth of 1 cm
with the same earth mixture: twice a day the pots are watered
.
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il 0~3Z10~3
by sprinkling. In post-emergence testing, the treated small
plants are allowed to dry. rrhe earth mixture is moistened by
placing the base of the pots in a tray containing water.
In both cases, the pots are kept in a greenhouse
(22 to 24C, 70 to 8Q% relative humidity) under artificial
light which provides 5,000 to 6,000 Lux at the level of the
plants, for 17 consecutive hours per day.
Three weeks after the start of the treatment, the
number of plants in each pot is counted, and their height
is measured.
The results are expressed in percentages relative
to the control plants.
¦ ~he results are summarised in the '~able which
! follows. The doses of active compound used are ln kg/hectare.
rrhe percentage destruction of treated plants is noted. In
the Table the figure O indicates that the compound is inactive,
the figure 100 indicates max~n~ activity.
.
- - 24 -
.
~z~
- - -. - - - - -
~- 1- 1- 1- 1-' ~
rS~ ~n ~ I_ O ~ CO ~ '~
. ~h
1- ~ 1- - ----_ ~ ~ n t
O 1-- O 1-- 01-- rx1 I-- Co I-- Co I-- r 1-- CO 1-- ~D ~- (D
. pJ l-h
_ _ __ _ _ _ _ __
`. 00 00 00 00 00 oo oo Ulo (D .
_ _ _ _ It
1_ ~ 1- 1-1- 1- 1-1- 1- ~ ~
O C5~ O O O ~) O O O r~o O O O ~:) ~) rl ~d
C~O 00 00 00 00 00 00 U10 1- L113
_ . _ W
.'. ' . O ~ ~1~> 0~ ~ 0~ ~ ~
Oo 00 O(n 00 00 00 00 00 ~ ~
. . .. b~ W
' . ~n u~ u~ ~ r~ ~ O ~ ~1 rD
I. . oo oo oo, oo oo oo oo oo
.. .. . _ ~ l_ . __ _~
~ Vl r Ul ~ ~ O r ,~1 ~n. ~D Ul
oo u~o 00 o~ oo ulo ulo oo ~
.... _ _- _ ~_
o o o o O o O o o o O o o o o O~
_ ~t
U~ O Ul O ~) ~1 ~ Ul ~ O ~1 O ~ ~ O
00 00 00 UlO 00 00 00 O IJ- ~3
_ _ _ ~ k
o ~9
. oo oo oo oo oo oo oo o ~ C~
_ _ . . _ W
1~ !~ (D
00 00 00 00 00 00 00 O ' 0
~ ~ ~ . .
00 00 00 00 00 00 00 O pJ, .
-- 25 --
~z~
The present invention also includes within its
scope a method of treating useful plants, lor example to
assist the setting of fruit, to prevent the shedding of
; leaves or fruit or to increase the formation of roots,
which comprises applying to the plant and/or its
environment a composition compxising a 1,2,4-oxadiazin-5-
one deri~ative of general formula I and a,carxier therefor
and/or at least one surface active agent as hereinbefore
described.
, A method for the control of weeds is also another
', , aspect of the present invention, said method comprising
applying to the weeds, or to a locus in which weeds are
growing or are expected to grow, a composition as mentioned
above for treating useful plants.
.
.
- '
,
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.
