Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
~04563Z
THIS INVENTION relates to insecticides and
more particularly, to synthetic insecticide~ of the
pyrethrin type, to their preparation, to compositions
containing them and to the insecticidal use of the
compounds and compositions.
In our Canadian Application No. 171,477
we have described and claimed esters of the general
formula:
3 2 IRl
R (R )C = C - C \ f H - COOR II
CH3 CH3
wherein Rl represents hydrogen or a methyl group: R2
represents hydrogen or a halogeno or alkyl group: R3
represents hydrogen or a halogeno, alkyl (which is
- differenb to R2 when R2 represents an alkyl group)
or carboalkoxy group which contains at lea~t 2 carbon
atoms in the alkoxy residue when R2 represents methyl
or R2 and R3 together with the carbon atom to which
they are attached represent a cycloalkylene ring
having at least one endocyclic.carbon to carbon double
bond; with the proviso that (a) R2 and R3 each
represent hydrogen only when Rl represents methyl and
(b) R3 contains at least 2 carbon atoms when Rl and
R each represent hydrogen: and R representq (a)
hydrogen (or a salt or acid halide derivative of
the acid) or an alkyl group, or (b) a group of formula:
_. ...
1045632
-- CH ~ Z--Y III
8
R ~H2.R12
or xl O
~ CH2 Y
x3/~
X4 0
CH
z3 ~ VI
zln Z2n
0~
~ CH2 . C--C~CH2-- VIA
0~
OCH2,C=C,CH2 VIB
2 --
~04S63Z
wherein Z represents 0, S, CH2 or C0, Y represents
hydrogen or an alkyl, alkenyl or alkynyl group or
an aryl or furyl group which is unsubstituted or
substituted in the ring by one or more alkyl,
alkenyl, alkoxy or halogeno groups, R7 and R8,
which may be the same or different, each represent
hydrogen or an alkyl, or alkenyl group,
R represents hydrogen or a methyl group,
R10 and R 1, which may be the same or different,
each represent hydrogen or an alkyl group,
R12 represents an organic radical having carbon-carbon
unsaturation in a position a to the CH2 group to which
R12 is attached,
~ indicates an aromatic ring or a dihydro or
tetrahydro analogue thereof,
xl, ~2, X and X4, which may be the same or different,
each represent hydrogen, chlorine or a methyl group,
Z3 represents -CH2- or -0- or -S- or -C0-, D
: represents H, CN or -C - CH, zl and z2, which may be
the same or different, each represent chlorine or a methyl
group and n=0, 1 or 2, with the proviso that R does not
represent hydrogen (or an acid chloride derivative of the
acid) or an ethyl or allethronyl group when Rl represents
hydrogen, R and R each represent chlorine and the
compound is racemic.
We now find that substantially pure optical
isomers of certain esters of formula II in which
represents hydrogen and R2 and R each represents
a halogen which is fluorine, chlorine or bromine, have
: - 3 -
1;0456;~Z
particularly potent insecticidal and/or knock down
properties.
Accordingly, the present invention provides a
cyclopropane carboxylic acid ester of the general formula:
R3
\ C = CH - CH CH - COOR
R2/ > \ IIA
CH3 CH3
wherein the cyclopropane carboxylate is in the form of
a substantially pure optical isomer with respect to the
cyclopropane ring and having the [R] configuration at C
of the cyclopropane ring and R2 and R3, which may be
the same or different, each represent fluorine, chlorine or
bromine and R represents 3-phenoxybenzyl or a-cyano-3-
phenoxybenzyl or, when at least one of R2 and R3 represents
fluorine, or when R2 and R3 each represent chlorine and the
cyclopropane ring has the [lR,cis~ configuration, R may
also represent 5-benzyl-3-furylmethylO
Our biological investigations indicate that esters
which are highly toxic to houseflies and mustard beetles are
derived from the dibromovinyl and from the dichlorovinyl
acid and esters structurally derived from these acidq are
preferred for this reason.
The stereochemistry of the esters around the
cyclopropane ring is such that the esters can exist
both as optical iQomers and geometrical isomers and our
biological investigations have indicated that ~or
the esters which are structurally derived from
3-phenoxybenzyl alcohol or its a-cyano analogue
, ,
~045632
and 2~2-dimethyl-3-(2~2-chloro- or dibrom~vinyl)
cyclopropane carboxylic acid, thc esters which are most
toxic to houseflies are those derived ~rom the [lR~cis~-
acid. Our biological investigations have al o indicated
that the toxicity of these particular esters? even when
derived from the [lR-trans] form of the acid, are still
exceptionally high, when compared to the toxicity of
existing pyrethroids and~ for this rcason, the [lR,trans
as well as op~ically active mixtures of cis and trans
i30mers are of interest.
The isomer~ of the present invention wherein R2
and R3 each represent fluorine and R represents 3-
phenoxybenzyl, a-cyano-3-phenoxybenzyl or 5-benzyl-3-
fuxylmQthyl have al30 been ~ound to have an unexpectedly
lS good oombination of toxic and knock-down propertie~ with
respect to houseflies. Intere~t in the fluorinated ~erie~
of esters centres on esters of the [lR~trans] a~d [lR~ci~]
acids.
For compounds of the invention which are substantially
pure optical isomers, we are u~ing the nomenclature [lR~cis]
and [lR~trana] as a convenient alternative to the strict
nomenclature based on the sequence rule tCahn. RS., Ingold C
and Prelog V~ angew. Chem. Int. Ed. 5 385 (1966) ) where,
for example, dihalovinyl cyclopropane carboxylates formally
derived from (+~-trans-[lR~3R~-chry~anthemates by replacement
of the vinyl methyl group~ wo~d be [lR,3S]. In acoordance
with our proposal, compounds we previously designated
(~)-ci~-[lR~3S] and (+)-trans-[lR,3R] are now designated
[lR, Ci8] and [lR,trans] respectively,
- 5 -
~04563Z
When the esters are derived from -cyano-3-
phenoxybenzyl alcohol, there is a further qite of molecular
asymmetry giving rise to a further site of optical activity
and these esters are obtainable in the (+), (+) or (-)
forms in relation to the stereochemi~try of the
"alcohol" part of the molecule.
One of our most toxic compounds to houseflies
and mustard beetles is (+)-a-cyano-3-phenoxybenzyl [lR,cis]-
2,2-dimethyl-3-(2,2-dibromovinyl) cyclopropanecarboxylate,
This ester has three centres of asymmetry giving rise to
optical isomers, two in the carbon atoms of the cyclopropane
ring and the other at the carbon atom bearing the a-cyano
substituent, Initially, we prepared this ester by the
reaction of (+)-a-cyano-3-phenoxybenzyl alcohol with the
acid chloride of the ~lR,cis] - acid giving an ester
in which the configuration at the carbon atoms of
the cyclopropane ring is retained but which is still
racemic at the carbon atom bearing the a-cyano
substituent. This product is a mixture of two stereo-
isomers and we have now found that one of these stereoisomers can be separated from the racemic mixture and
that, surprisingly, the stereo isomer which can be
separated is a crystalline isomer which exhibits
a higher insecticidal activity than the racemic mixture.
The esters of the present invention may be
prepared by the methods disclosed in our earlier
; mentioned application e.g. wherein a carboxylic acid
or esterifiable derivative thereof of formula:
- 6 -
"
104563Z
R2 C CH ~ CH - COQ '
\ C/
/ \
CH3 ~H3
is reacted with a compound of formula RQ, where Q' and Q
are functional groups which react together to form an ester
linkage and R2, R3 and R are as defined in claim 1,
the resolution into the desired configuration on the
cyclopropane ring taking place before or after formation
of the ester linkage. I~hen the ester is to be prepared
in the form of a pure optical anq~or geometrical isomer
in relation to the acid part of the molecule, it is
preferred to use the ester precur~or in the form of
the desired optical and/or geometrical isomer rather
than to attempt to resolve the ester after its preparation.
Thus, in the case where the ester is preparcd by the
reaction of an alcohol or derivative thereof with the
acid or a derivative thereof, the reaction can be carried
out using the appropriate isomer of the acid or derivative
thereof, e.g. the [lR,cis] isomer. The preparation of
trans isomers of the acids is described in our earlier
mentioned application. The cis-isomers of the acids can be
prepared by modification of the proceqses described
in that complete specification in which the trans-
chrysanthemates are replaced by cis-chrysanthemates.
- 7 ~
104563Z
In order to isolate the stereo isomer of
~-cyano-3-phenoxybenzyl [lR,cis]-2,2-dimethyl-3-
(2,2-dibromovinyl) cyclopropane carboxylate which is
optically pure at the carbon atom bearing the a-cyanO
substituent and which is substantially free from
other optical isomers, (+)-~-cyano-3-phenoxybenzyl
[lR,cis]-2,2-dimethyl-3-(2,2-dibromovinyl)cyclopropane
carboxylate may be dissolved in a solvent, particularly
a hydrocarbon solvent such as hexane, at a temperature
up to about 60C and the solution then cooled, when
one of the stereo isomers, having [S] configuration in
the alcohol residue will crystallize out from the solution.
The [s] stereo isomer may be removed from the solution,
e.g. by filtration and the solution evaporated to dryness
to leave a residue comprising the other stereo-isomer, the
[R]-isomer, contaminated with small quantities of the
[S~-isomer. Nuclear magnetic resonance indicates
that the crystalline isomer is substantially one form
while the non-crystalline isomer contains traces of
the other stereo isomer i.e. the crystalline
stereo isomer. While the insecticidal activity of the
crystalline stereo isomer is found to be higher than
the racemate, the insecticidal activity of the non-
crystalline isomer is found to be iess than that of the
racemate.
The dextro rotatory ~tereo isomer
-- 8 --
104S63Z
which can be readily separated from the racemic mixture
is derived from the t-) isomer of the alcohol and the
ester has the ~S] ab,sol.ute configuration in the
alcohol residue.
The fluorovinyl cyclopropane carboxylic acids
and their salts, acid halides and lower alkyl esters
of formula IIA (~ = R = F, R=H (or a salt or acid
halide thereof) or Cl - C4 alkyl) are new compounds
which can be prepared by the general method described
in our above mentioned ap~lication. This involves
reaction of an aldehyde of formula XIA with a phosphorane
or ylide of formula X under the conditions of the Wittig
reaction.
: ~3 z4
\ C = P ~ 4 + O = CH -CH -- CH -- COOR
R.2/ \~ z4 \C/
H3 ~3
X XIA
In formulae X and XIA, R2 and R3 are as
defined above and R is a group as defined above which
will not interfere in the Wittig reaction such as a
methyl or tert, butyl group and Z4, which in principle
can represent any organic radical, will normally be
a phenyl radical since the stability of the tri-
substituted phosphorus oxide which is formed as the
by-product in the reaction is particularly high. The
phosphorane of formula X can be prepared in situ
by introducing the aldehyde XIA into the reaction
mixture together with the triorganophosphine PZ4 and
104563Z
a salt of the appropriate chlorofluoroacetic acid
in accordance with proceclures ];nown ~er se.
The isomers of the present invention where
R represents a 3-phenoxybenzyl, ~-cyano-3-phenoxybenzyl
or 5-benzyl-3-furylmethyl group can be prepared
directly by the ~ittig reaction mentioned above
by using a starting aldehyde of appropriate configuration
in which R represents the required ester group required
in the final product in accordance with the second
method disclosed in our earlier mentioned application.
m e esters of this invention may be formulated
into insecticidal compo~itions of the type described
in our earlier mentioned application and the compounds
and the compositions may be used to control insects
in the manner described in our earlier mentioned
application.
The following examples are given to illustrate
the invention: Refractive indices are measured at 209C.
EXAMPIE 1
Methyl-[LR,cisl-caronaldehyde was obtained by
ozonolysis of methyl (+)-cis-chrysanthemate. The
procedure described in Example 16 of our above
identified application was then repeated using 5.3 g
triphenylphosphine, 3.36 g carbon tetrabromido and
60 mls. dry dichloromethane and 1.5 g methyl-[lR,cisl-
caronaldehyde. ~rhe raaction product was then refluxe~
3 hours with 9 mls. acetic acid, 6 mls. concentrated HBr
and 3 mls. water and then diluted with water and extracted
with ether. rrhe organic solution was extracted with
--10--
1045632
dilute ~odium hydroxide and thi~ extract acidified
and extracted with ether and evaporated to give a
residue of [lR,cis]-2,2-dimethyl-3-(2,2-dibromovinyl)-
cyclopropane carboxylic acid.
The carboxylic acid described above was
converted to its acid chlorido by reaction with
thionylchloride in pyridine as described in Example 17
of our above identified application and the re~ulting
ac~d chloride reacted with 3-phenoxybenzyl alcohol
in dry benzene in the presence of pyridine as described
in Example 17 of our above identified application
to give 3-phenoxybenzyl [11~, ~ -2,2-dimethyl-3-
~2,2-dibromovinyl)cyclopropane carbQxylate, mp 93,
nD 1.5848. (Compound P29A).
The esterification described above was
.. .
repeated by replacing 3-phenoxybenzyl alcohol by
-cyano-3-phenoxybenzyl alcohol to give (~
. . cyano-3-phenoxybenzyl [lR, Ci8 ]-2,2-dimethyl-3-(2,2-
- dibromovinyl) cyclopropane carboxylate, nD 1,5732
(Compound P29 B).
EXAMPLE 2
The esterification procedures described in
Example 1 were repeated replaci~ng the rlR,cis]-
dibromovinyl acid by ~LR,tran~-2,2-dimethyl-3-
(2,2-dibromovinyl)-cyclopropane carboxylic acid
(obtained as d~scribed in Example 16 of our above
identified application), ~l~,transl-2,2-
dimethyl-3-(2,2-dichlorovinyl)cyclopropane carboxylic
acid (prepared as described in EXample 15 of our
-- ~i --
~;)45632
above identified application). m e following
esters were prepared:
3-phenoxybenzyl[lR~trans3-2~2-dimethyl-
3-(2,2-dibromovinyl) cyclopropane carboxylate,
S nD 1.5828 (Compound P29C).
(+)-a-cyano-3-phenaxybenzyl [lR-trans]-
2~2-dimethyl-3-(2,2-dibromovinyl) cyclopropane
carboxylate, nD 1.5664 (Compound P29D).
~+)-a-cyano-3-phenoxybenzyl (lR,trans~-
2~2-dime~hyl-3-(2~2-dichlorovinyl) cyclopropane
car~oxylate, nD 1.5498 (Compound P29E)~
(~)-a-cyano-3-phenoxybenzyl [lR,c ]-
2,2-dimethyl-3-(2,2-dichlorovinyl) cyclopropane
carboxylate, (Compound P29J), nD 1.5622.
m e required i80mer of the acid for the
la~t me~tioned ester was obtained by resolution as
de~cribed in Example 7.
,:
.
- 12 -
~04563Z
EXAMPLE 3
~ +)-a-cyano-3-phenoxybenzyl [lR,cis]-
2,2-dimethyl-3-(2,2-dibromovinyl)cyclopropane
carboxylate was prepared by the procedure described
in Example 1. This racemate has the following
physical characteristics:
[a]2o 1 (C=0.4 in ethanol)
nD 1.5732
N.M.R. peaks associated with the C-H
group (carbon atom bearing the a-cyanO substituent)
~=3.65 and 3.72 (equal areas).
0.6 grams of the racemate was dissolved
in 25 ml. hexane and maintained at -20C until
precipitation of crystals was complete. The crystals
were the filtered off and recrystallised from hexane
to give the [lR,cis]-2,2-dimethyl-3-(2,2-dibromovinyl)
cyclopropane carboxylate of (-)-a-cyano-3-phenoxyben
alcohol in 0.25 g yield. This isomer has [S~
configuration at the carbon atom carrying the a-cyano
group. The physical characteristics of this
crystalline isomer are as follows:
m.p. 100C
[a]20 + 16 (C=0.4 in ethanol)
~.M.R. peaks associated with the C-H group
(carbon atom bearing the a_cyanO substituent) 'C = 3.65
but no peak at ~ = 3.72.
The mother liquors were combined and evaporated
104563Z
to dryness to give 0.32 g of the non-crystalline isomer
of the [lR,cls]-2,2-dimethyl-3-(2,2-dibromovinyl)
cyclopropane carboxylate of (+)-a-cyano-3-phenoxybenzyl
alcohol having the following properties:
nD 1.5749
[]20 _ 15 (C=o.4 in ethanol)
This isomer has [R] configuration at the carbon
atom carrying the a-cyano group.
N.M.R. peaks associated with the C-H bond
(carbon atom bearing the -cyano group)~= 3.72 with a
small peak (2~/o of the 3.72 peak) at 'r=3.65 attributable
to the crystalline isomer.
In the above examples, temperatures are in
degrees centigrade and refractive indices are measured
at 20C.
The insecticidal toxicity of the compounds
described in Examples 1-3 were tested against houseflies
and mustard beetles by the procedures described in our
above identified application and the following
relative toxicities were obtained in relation to
5-benzyl-3-furylmethyl (+)-trans-chrysanthemate which
is arbitrarily assigned a toxicity of ~000.
Com~ounds Houseflies Mustard Beetles
5-benzyl-3-furylmethyl-(+)-
trans-chrysanthemate 1,000 1,000
P29A 2,200 1,600
P29B 10,000 il,000
Crystalline isomer of
Compound P29B 23,000 14,000
Non-crystalline isomer of
Compound P29B. 3,500 4,000
P29C 1,100 4,000
104563Z
Compounds Houseflies Mustard Beetles
P29D 4,100 5,200
EXAMPLE 4
~lR,-Transl-3-(2(2-difl~orovinvl)-2,2-dimethyl
cYcloPropane carboxYlic acid.
a) A mixture of freshly distilled, dry, dimethyl
formamide (20 ml), triphenylphosphine (7.g g), methyl-
[lR,-trans]-caronaldehyde (3.0 g) and the sodium salt
of chlorodifluoro acetic acid (3.6 g) were heated at
90C with stirring for 20 hours. Water (60 ml) were
then added and the solution extracted with 2 x 30 ml
portions of diethylether. The combined ethereal extracts
were washed with water, saturated sodium carbonate
solution, saturated sodium chloride solution, and then
dried over sodium sulphate and the ether distilled off.
Distillation of the residue gave 2.25 g of methyl[lR,-
trans]-3-(2,2-difluorovinyl)-2,2-dimethyl cyclopropane
- carboxylate, b.p. 63C/20 mm, nD 1.4209.
b) An alkaline solution was prepared by dissolving
sodium hydroxide (200 mg) in water (1 ml) and ethanol
(10 ml) was added. The methyl ester described above
(0.5 g) wa~ stirred intothe alkaline solution and the
mixture was refluxed for 1 hour. ~he solvents were
removed under reduced pressure and water (30 ml) added.
The solution was washed with 2 x 20 ml portions of
diethylether and acidified with concentrated hydro-
chloric acid. The mixture was extracted with 2 x 30 ml
portions of diethylether, washed with saturated sodium
chloride solution, dried over sodium sulphate and the
solvents evaporated to leave 410 mg of [lR,-trans ]
10456;~2
3-(2,2-difluorovinyl)-2,2-dimethyl cyclopropane
carboxylic acid as an oil having nD 1.4400.
EXAM2LE 5
rlR~cisl-3-( 2l2-difluorovinyl)2r2-dimethyl
cYclopropane carboxYlic acid
a) The procedure described in Example 4a above was
repeated using 1.5 g methyl[lR,-cis]-caronaldehyde
2.92 g triphenylphosphine, 1.2 g sodium chlorodifluoro
acetate and 7 ml dimethylformamide. The residue
obtained after evaporating the final diethyl ether
extract was itself extracted with 3 x 40 ml portions
of petroleum ether and the petroleum ether evaporated
and the residue distilled to give 440 mg of methyl
[lR,-cis}3-(2,2-difluorovinyl)2,2-dimethyl cyclopropane
carboxylate b.p. 74 - 78C/20 mm nD 1.4288.
b) The methyl ester obtained above (380 mg) was added
to a solution of sodium hydroxide (200 mg)~n water
(1 ml) and ethanol (10 ml). The mixture was refluxed
for 1 hour with stirring and the solvents removed under
reduced pressure. Water (50 ml) was then added and the
solution washed with 20 ml diethylether, acidified with
concentrated hydrochloric acid and extracted with
diethyl ether. The ethereal extract was washed with
saturated sodium chloride, dried over sodium sulphate
and evaporated to give 290 mg of [lR,-cis]-3-(2,2-
difluorovinyl)-2,2-dimethyl cyclopropane carboxylic acid,
nD 1.4456.
- 16 -
.... . .. .
1045632
EXAMæLE 6
The acids described in Examples 4 and 5
were esterified with 5-benzyl-3-furylmethyl alcohol,
3-phenoxybenzyl alcohol and t+)-a-cyano-3-phenoxybenzyl
alcohol by the following procedure. A solution of the
acid(llO mg) in benzene (5 ml) was treated with
pyridine (50~ul) and thionyl chloride (45 ul) and left
to stand for three hours at the end of which time,
the acid has been converted into its acid chloride,
A solution of 3-phenoxybenzyl alcohol (137 mg)
or an equivalent quantity of the other alcohols and
pyridine (50 ~1) in benzene (5 ml) was added
to the acid chloride and the mixture left to stand
over night. The desired ester was recovered from the
solution by passing it through a column of neutral
alumina and eluting the column with benzene. The eluate
was evaporated to leave the ester as an oil, the
following results being obtained.
Com~ound Acid Alcohol nD
P31A lR,-trans 5-benzyl-3-furyl 1.5142
methyl
P31B lR,-trans 3-phenoxy-benzyl 1.5293
P31C lR,-trans (~) a-cyano-3- 1.5330
phenoxy-benzyl
P3LD lR,-cis 5-benzyl-3-furyl 1.513
methyl
P31E lR,-cis 3-phenoxybenzyl 1.5349
P3LF lR,-cis (+)-a-cyano-3- 1.5355
phenoxybenzyl
- 17 -
~045632
EXAMPLE 7
(+)-Ci s-trans-2,2-dimethyl-3-(2,2-dichlorovinyl)
cyclopropane carboxylic acid, prepared by reacting
ethyl diazoacetate with l,l-dichloro-4-methylpe~ta-
1,3-diene and hydrolysing the resulting ethyl ester,
was separated into the (+)-cis and (+)-trans isomers by
selective crystallisation in n-hexane, in which the
cis isomer is more soluble. The substantially pure
cis and trans isomers were then resolved into their
individual optical isomer~ by the following procedure.
Resolution of (+)-cis-2,2-dimethyl-3-(2,2-dichlorovinyl)-
cyclopropanecarboxyl_c acid. - The (+)-cis acid (14.6 g)
in benzene (250 ml), and (+~--methylbenzylamine (8.47 g)
in benzene (30 ml) were mixed at 50, and allowed to
cool to 20 overnight. The precipitate (13.2 g, 58%
required isomer) was recrystallised 3 times from
benzene to give the (+)-a-methyl benzylamine salt of
the [lS,-cis] acid (1.7 g) m.p. 1350, [a]D-17.1 (c,
1.6 in EtOH) was isolated. Repetition, using (-)--
methylbenzylamine gave, after 3 crystallisations, the
(-)--methyl-benzylamine salt of the [lR,-cis] acid
(6.1 g) m.p. 147 []D-26.1 (c,1.9 in EtOH) and from
the mother liquors the (-)-a-methylbenzylamine salt
of the [lS,-cis] acid (3.8 g) m.p. 139 []D + 14.8
(c,2.0 in EtOH).
Each of the four ~alts was shaken with benzene
(50 ml) and 3N HCl (50 ml) and the benzene layer
processed to give the reRolved acidR. ThuR were obtained
[lS,-cis]-2,2-dimethyl-3-(2,2-dichlorovinyl)cyclopropane
carboxylic acid (4.6 g) m.p. 90 []D ~ 26.9 (c, 1.7 in
.. , . . . _, .
104563Z
CHC13) and [lR,-cis]-2,2-dimethyl-3-(2,2-dichlorovinyl)
cyclopropane carboxylic acid (3.9 g) m.p. 90 []D +
27.2 (c, 2.1 in CHC13).
Resolution of (+)-trans-2,2-dimethYl-3-(2,2-
dichlorovinYl)cYclopropane carboxylic acid. - The
(+)-trans acid (15.6 g) in benzene (180 ml and L-(+)-
threo-l-p-nitro-phenyl-2-N,N-dimethylaminopropane-
1,3-diol (18.0 g) in benzene (180 ml) were mixed at 50
and cooled to 20 during 2 days. The precipitate
(14.2 g) was recrystallised 3 times from trichloroethylene
to give the L-(+)-threo-l-p-nitrophenyl-2-N,N-dimethyl-
aminopropane-1,3-diol salt of [lS,-trans]-2,2-dimethyl-3-
(2,2-dichlorovinyl3 cyclopropanecarboxylic acid (8.9 g)
m.p. 129-131 []D + 7 4 (c, 2.1 in EtOH). Correspondingly
D-(-)-threo-l-p-nitrophenyl-2-N,N-dimethylaminopropane-
1,3-diol gave the salt with the [lR,-trans] acid (9.4 g)
m.p. 129-131, [a]D-7.3 (c, 2.0 in EtOH). Decomposition
of the salts with 3~ HCl as described ~or the cls
acids gave [lS,-trans]-2,2-dimethyl-3-(2,2-dichlorovinyl)
cyclopropane carboxylic acid (3.8 g) m.p. 68-73, []D-
34.6 (c, 1.9 in EtOH) and [lR,-trans]-2,2-dimethyl-3-(2,2-
dichlorovinyl cyclopropane carboxylic acid (4.1 g)
m.p. 69-73, [a]D + 33.0 (c, 2.0 in EtOH).
The [lR,-cls] and [lR,trans] acids were converted
to their acid chloride and reacted with 3-phenoxybenzyl
alcohol by the procedure described in Example 1 to give
the 3-phenoxybenzyl ester of [lR,-cis] aAd of [lR,-trans-]
2,2-dimethyl-3-(2,2-dichlorovinyl)-cyclopropane carboxylic
-- 19 --
1~)4563Z
~cid, compounds P29L and P29M respectively.
The [1~ - ~ acid was also esterified with 5-benzyl-
3-furylmethyl alcohol by the same procedure to give
compound P29N, 5-benzyl-3-furylmethyl [lRj-c B-]
2~2-dimethyl-3-(2,2-dichlorovinyl) cyclopxopane
carbcxylate.
me toxicity of these new e6ters was tested
by the procedure described in detail in our above mentioned
application and the following results were obtained:
...
: Compound~ Relative Toxicity
.
Hou~eflies MNstard Beetles
_ ~ _ _ r
S-benzyl-3-furylmethyl
[l~-tra~n chrysanthemate
: ~Bioresmethrin) 1,000 1,000
P29L 1,600 1,400
P29M 740 2,100
~ P29~ 2,600 2,200
; ~
;
me toxicity of compounds P29L and P29M relative
to bioresmethrin was also determined again9t the
American cockroach, Peri~laneta ~mcrii31gg ~. with the
following results.
.. .,, . ._ .
. Compound Relative Toxicity
. . ~. . , . ..
Biore6methrin 100 *
P29L 2,100
P29M 800
. ~ LD50=2-5~ug/insect
-20 -
