Insecticidal method utilizing certain coumaranol esters of cyclopropane carboxylic acids

Cyclopropanecarboxylic acid esters of 3-coumaranol and substituted 3-coumaranols possessing useful insecticidal properties.

BACKGROUND OF THE INVENTION 
This invention relates to novel cyclopropanecarboxylic acid esters of 
3-coumaranol, and derivatives thereof, as well as insecticidal 
compositions containing said esters as an essential active ingredient. 
Current trends in the chemical control of insects call for inherently safer 
materials which degrade very rapidly to non-toxic substances once their 
purpose is accomplished. The safety of the widely used chlorinated 
hydrocarbons, notably DDT, is currently under question largely because of 
their poor biodegradability and concomitant persistence. Accordingly, 
there is a great demand for alternative broad spectrum insecticides which 
are suitable for the high volume usage entailed in agricultural 
applications. At the same time it is desirable for new insecticides to 
exhibit a low order of toxicity to warm-blooded animals. Of the several 
insecticidal classes which demonstrate low mammalian toxicity and good 
biodegradability, it has long been recognized that pyrethrum, a 
naturally-occurring insecticidal mixture, possesses these desirable 
properties. In addition to the safety advantages, this natural mixture 
causes rapid knock-down and kill of a broad spectrum of insects; however, 
it is unstable to light, air, and heat, and is very expensive. The most 
active component of pyrethrum is pyrethrin I and a number of analogous 
compounds have been proposed for insecticidal use. Allethrim, a typical 
synthetic pyrethrin-like insecticide, while more stable to light and heat 
than pyrethrum, is nevertheless expensive, a defect which is compounded by 
the fact that this substance is not appreciably synergized by the low cost 
synergizing agents such as piperonyl butoxide which are typically used in 
insecticidal compositions. Because of instability, high cost and limited 
supply, the use of pyrethrum and pyrethrin-like insecticides in 
agricultural applications has been precluded or seriously limited. 
At the same time, it is well known that certain insects, in time, become 
immune to the insecticidal properties of various chemical agents. To be 
efficient, an insecticide should be able to resist detoxification by the 
insect. While biological mechanisms whereby insects are capable of 
detoxifying the various types of insecticidal compounds are not fully 
understood, it is possible that, as with other biological systems, insects 
may in time develop new biochemical processes capable of detoxifying any 
particular insecticidal compound. In any event, it is desirable to have 
included in the insecticidal armamentarium compounds which can be utilized 
once a given class of insects is found no longer to respond to 
conventional insecticidal compounds. 
Many prior art insecticidal esters differ from one another and from the 
natural pyrethrin I esters by virtue of synthetic modifications in the 
alcohol moiety of the ester. Other synthetic insecticides are 
pyrethrin-like esters modified in the acid portion of the ester molecule. 
For example, the applications of Fanta, entitled "INSECTICIDAL ESTERS OF 
3-(2,2-TETRAMETHYLENE ETHENYL)-2,2-DIMETHYLCYCLOPROPANECARBOXYLIC ACID," 
Ser. No. 23,513, filed Mar. 17, 1970 (now U.S. Pat. No. 3,679,667, issued 
July 25, 1972); NOVEL ESTERS OF CHRYSANTHEMIC ACID", Ser. No. 2,443, filed 
Jan. 12, 1970 (now abandoned); the copending application of Crawford, 
entitled "INSECTICIDAL ESTERS OF 1-ACENAPHTHENOL", Ser. No. 198,434, filed 
Nov. 12, 1971, and now U.S. Pat. No. 3,840,584, issued Oct. 8, 1974; and 
U.S. Pat. No. 3,465,007, Sept. 2, 1969, to M. Elliott, all relate to 
various synthetic insecticidal esters of the pyrethrum type. It has now 
been discovered that 3-coumaranol, and the various derivatives thereof, 
can be used in conjunction with cyclopropanecarboxylic acids to provide 
insecticidal esters of the pyrethrum type. 
It is therefore an object of this invention to provide novel insecticidal 
3-coumaranol esters of cyclopropanecarboxylic acids which are 
biodegradable, effect rapid knock-down and kill of a broad spectrum of 
insects, possess low mammalian toxicity and are less susceptible to 
detoxification by insects than is pyrethrum. This and other objects are 
obtained by the present invention as will become apparent from the 
following disclosure. 
SUMMARY OF THE INVENTION 
The novel compounds of the present invention include certain 
cyclopropanecarboxylic acid esters of 3-coumaranol and substituted 
derivatives of 3-coumaranol. (The "3-coumaranol" compounds may be 
alternatively named as derivatives of 2,3-dihydro-3-benzofuryl compounds; 
the "chrysanthemic acid" esters herein can also be named as derivatives of 
2,2-dimethyl-3-(2-methylpropenyl)cyclopropanecarboxylic acid.) 
This invention also encompasses insecticidal compositions comprising as an 
essential ingredient an insecticidal amount of certain 
cyclopropanecarboxylic acid esters of 3-coumaranol or a substituted 
3-coumaranol. 
As a method aspect, the present invention encompasses a method of 
combatting insects comprising applying an insecticidal amount of a 
cyclopropanecarboxylic acid ester of 3-coumaranol or substituted 
3-coumaranol to an insect or insect habitat. 
DETAILED DESCRIPTION OF THE INVENTION 
The cyclopropanecarboxylic acid esters of 3-coumaranol, and derivatives of 
3-coumaranol are of the formula 
##STR1## 
wherein R is a cyclopropane moiety selected from the group consisting of 
##STR2## 
wherein n is an integer of from 4 to 6, preferably 4, and wherein R.sup.1 
is a 3-coumaranyl moiety of the formula 
##STR3## 
wherein R.sup.2 is selected from the group consisting of hydrogen, 
halogen, nitro, thiomethyl, alkyl (e.g., ethyl, methyl, propyl, butyl, 
neopentyl, isopropyl,), alkoxyl (e.g., methoxyl, ethoxyl), sulfonylmethyl, 
phenyl, benzyl, and the like. The esterification is at the 3-position on 
the coumaranol ring system. 
The insecticidal compounds of this invention are prepared by esterifying 
3-coumaranol and substituted derivatives thereof, with 
cyclopropanecarboxylic acids or acid halides in the manner hereinafter 
detailed. First, the 3-coumaranol compound is prepared by reacting 
salicylaldehyde or a 5-substituted salicylaldehyde with 
dimethyloxosulfonium methylide to secure the corresponding 3-coumaranol in 
accordance with the method described by B. Holt and P. A. Lowe, 
Tetrahedron Letters, No. 7, 683 (1966) as detailed by E. J. Corey and M. 
Chaykovski, J. Amer. Chem. Soc., 87, 1353 (1965). The reaction proceeds as 
follows: 
##STR4## 
wherein R.sup.2 is as above. Following this, the 3-coumaranol compound is 
esterified, e.g., by means of a cyclopropanecarboxylic acid halide, as 
follows: 
##STR5## 
wherein R is as disclosed above. 
According to the above outline, the esters of this invention are prepared 
by a step-wise process comprising: (1) preparing the 3-coumaranol compound 
according to the procedures described in the foregoing references; (2) 
esterifying the alcohol with a stoichiometric amount of a 
cyclopropanecarboxylic acid chloride which is also prepared by standard 
procedures (below). 
Alternatively, the esterification step of the present invention can be 
effected in other ways. The 3-coumaranol compound can be heated with the 
appropriate cyclopropanecarboxylic acid in the presence of a strong acid 
(e.g., H.sub.2 SO.sub.4, HClO.sub.4, etc.) in an organic solvent capable 
of azeotropically boiling with water, thereby removing the water formed in 
the esterification. THe 3-coumaranol compound can also be heated with a 
lower alkyl ester of a cyclopropanecarboxylic acid in the presence of a 
basic catalyst such as sodium hydroxide, potassium hydroxide, sodium 
alcoholate or potassium alcoholate, and the like, while continuously 
removing the lower alcohol formed through trans-esterification of the 
reaction system. In such cases, the methyl, ethyl, n-propyl and iso-propyl 
esters of the cyclopropanecarboxylic acids are suitable. In the most 
preferable esterification, the 3-coumaranol compound is allowed to react 
with a cyclopropanecarboxylic acid halide, preferably at temperatures from 
about 20.degree. C. to about 100.degree. C., in an inert solvent, 
preferably in the presence of an agent such as pyridine, triethylamine or 
other suitable amine, such that the esterification proceeds with the 
formation of a hydrohalic acid salt within a short period of time. For 
this purpose, the cyclopropanecarboxylic acid chloride is the most 
preferred, although the acid bromide and the acid iodide can be employed. 
The cyclopropane carboxylic acids used to prepare the insecticidal esters 
of the instant invention can be prepared by standard procedures disclosed 
in the art. U.S. Pat. No. 3,679,667, July 25, 1972, to W. J. Fanta, above, 
describes the preparation of 3-(2,2-tetramethylene 
ethenyl)-2,2-dimethylcyclopropanecarboxylic acid; chrysanthemoyl chloride 
can be prepared in the manner of Crombie, et al., J. Chem. Soc. 3552 
(1950); 2,2,3,3-tetramethylcyclopropanecarboxylic acid can be prepared in 
the manner of Matsui and Kitahara, Agr. Biol. Chem. (Tokyo) 31, 1143 
(1967) and converted to the acid chloride using thionyl chloride. 
Exemplary 3-coumaranol compounds useful herein include the 5-halo-(i.e., 
fluoro, chloro, bromo and iodo) 3-coumaranols, 5-nitro-3-coumaranol, 
3-coumaranol, 5-methoxy-3-coumaranol,5-butoxy-3-coumaranol, 
5-decyl-3-coumaranol, 5-sulfonylmethyl-3-coumaranol, 
5-thiomethyl-3-coumaranol and the like. 3-Coumaranol compounds preferred 
for use in the preparation of the compounds of this invention by virtue of 
their low cost, ease of preparation and the high insecticidal activity of 
the cyclopropanecarboxylic esters which they form include: 3-coumaranol, 
5-methoxy-3-coumaranol, 5-chloro-3-coumaranol, 5-methyl-3-coumaranol and 
5-nitro-3-coumaranol. 
The compounds of this invention can exist in several isomeric and optically 
isomeric forms, e.g., cis-configuration, trans-configuration, dextro- and 
levorotatory forms of each, etc., and mixtures and racemates thereof. It 
is intended that the claims herein be construed to encompass all such 
forms and mixtures thereof. Preferred insecticidal esters herein are 
3-coumaranyl chrysanthemate, 5-chloro-3-coumaranyl chrysanthemate, 
5-nitro-3-coumaranyl chrysanthemate, 5-methoxy-3-coumaranyl 
chrysanthemate, 3-coumaranyl 2,2,3,3-tetramethylcyclopropanecarboxylate, 
5-chloro-3-coumaranyl 2,2,3,3-tetramethylcyclopropane-carboxylate, 
5-nitro-3-coumaranyl 2,2,3,3-tetramethylcyclopropanecarboxylate, 
5-methoxy-3-coumaranyl 2,2,3,3-tetramethylcyclopropanecarboxylate, 
3-coumaranyl 3-(2,2-tetramethylene 
ethenyl)-2,2-dimethylcyclopropanecarboxylate, 5-chloro-3-coumaranyl 
3-(2,2-tetramethylene ethenyl)-2,2-dimethylcyclopropanecarboxylate, 
5-nitro-3-coumaranyl 3-(2,2-tetramethylene 
ethenyl)-2,2-dimethylcyclopropanecarboxylate, 5-methoxy-3-coumaranyl 
3-(2,2-tetramethylene ethenyl)-2,2-dimethylcyclopropanecarboxylate, 
5-phenyl-3-coumaranyl chrysanthemate, 5-benzyl-3-coumaranyl 
chrysanthemate, 5-phenyl-3-coumaranyl 
2,2,3,3,-tetramethylcyclopropanecarboxylate, 5-benzyl-3-coumaranyl 
2,2,3,3,-tetramethylcyclopropanecarboxylate, 5-phenyl-3-coumaranyl 
3-(2,2-tetramethylene ethenyl)-2,2-dimethylcyclopropanecarboxylate and 
5-benzyl-3-coumaranyl 3-(2,2-tetramethylene 
ethenyl)-2,2-dimethylcyclopropanecarboxylate. 
The preparation of the coumaranyl cyclopropanecarboxylic acid esters of the 
present invention is described in more detail in the following examples. 
The inert organic solvents used in the procedures are those which do not 
react with the 3-coumaranyl compounds or with the cyclopropanecarboxylic 
acids or acid halides. Such solvents are preferably aprotic solvents such 
as hexane, benzene, acetone, ether, glyme, and the like. The examples are 
not intended to be limiting but only to demonstrate the preparation of a 
variety of compounds of this invention.

EXAMPLE I 
Step 1. According to the precedure of Corey and Chaykovski, above, a 
nitrogen blanketed mixture of 2.52 g. (0.064 mol.) of sodium hydride (as a 
61% mineral oil dispersion) and 14.1 g. (0.064 mol.) of 
trimethyloxosulfonium iodide was stirred and treated dropwise over 15 min. 
with 70 ml. of dry dimethyl sulfoxide. The reaction mixture was then 
cooled to 10.degree. C. and a solution of 7.32 g. (0.06 mol.) of 
salicylaldehyde in 30 ml. of dry dimethyl sulfoxide was added in one 
portion with stirring. After 5 min. the cooling bath was removed and 
stirring was continued at room temperature for 2 hours and at 50.degree. 
C. for 1 hour. The cooled reaction mixture was poured into ice water and 
the aqueous mixture extracted with ether. The combined ether extracts were 
washed twice with water, once with saturated salt solution, and dried over 
magnesium sulfate. Evaporation of the solvent at reduced pressure yielded 
7.2 g. (88%) of 3-coumaranol). 
Further purification by passing through a Florisil column afforded 5.87 g. 
of product: ir (neat) 2.98, 6.20, 6.23, 6.75, 8.1, 10.4, 13.2.mu.; nmr 
(CCl.sub.4) .tau. 3.0 (multiplet, 4 hydrogens, aromatic), 5.0 (multiplet, 
1 hydrogen, -CHOH), 5.81 (multiplet, 2 hydrogens, --CH.sub.2 --), 6.62 
(singlet, 1 hydrogen, OH). 
Step 2. A mixture of 11 g. (0.059 mol.) of (.+-.)chrysanthemoyl chloride 
(mixture of cis- and trans-isomers) and 9.5 g. (0.12 mol.) of dry pyridine 
in 125 ml. of dry benzene was cooled to 0.degree. C. A solution of 8.05 g. 
(0.059 mol.) of the 3-coumaranol prepared in the first step in 25 ml. of 
dry benzene was added with stirring over several minutes. The cooling bath 
was removed and the reaction mixture was stirred at room temperature for 
24 hours. The reaction was added to saturated salt solution and the layers 
were separated. The aqueous layer was further extracted with ether and the 
combined organic layers were washed twice with 3% aqueous hydrochloric 
acid and several times with saturated salt solution prior to drying with 
magnesium sulfate. Evaporation of the solvent at reduced pressure gave 20 
g. of crude ester product. This was purified by passing through a Florisil 
column to yield 14 g. (83%) of (.+-.) cis,trans-3-coumaranyl 
chrysanthemate: ir(neat) 3.42, 5.79, 6.20, 6.23, 8.61, 13.2.mu.; 
nmr(CCl.sub.4) .tau. 2.64-3.4 (multiplet, 4 hydrogens, aromatic) 3.92 
(multiplet, 1 hydrogen, 
##STR6## 
4.75, 5.26 [ 2 doublets, 1 hydrogen, J = 8 Hz, cis and trans 
(CH.sub.3).sub.2 C.dbd.CH-] 5.62 (multiplet, 2 hydrogens, --CH.sub.2 O--), 
8.36 [singlet, 6 hydrogens, (CH.sub.3).sub.2 C.dbd.], 8.78, 8.90 [2 
singlets, 
##STR7## 
n.sub.D.sup.25.degree. 1.5271. 
In the above procedure, the chrysanthemoyl chloride is replaced by an 
equivalent amount of 3-(2,2-tetramethylene 
ethenyl)-2,2-dimethylcyclopropanecarboxylic acid chloride and 
2,2,3,3-tetramethylcyclopropanecarboxylic acid chloride, respectively, and 
the compounds 3-coumaranyl 3-(2,2-tetramethylene 
ethenyl)-2,2-dimethylcyclopropanecarboxylate and 3-coumaranyl 
2,2,3,3-tetramethylcyclopropanecarboxylate are secured. 
EXAMPLE II 
In the same manner as described in Example I, Step 1, 1.26 g. (0.032 mol.) 
of sodium hydride (as a 61% mineral oil dispersion) and 7. g. (0.032 mol.) 
of trimethyloxosulfonium iodide in 35 ml. of dry dimethyl sulfoxide was 
treated with a solution of 4.68 g. (0.030 mol) of 5-chlorosalicylaldehyde 
in 15 ml. of dimethyl sulfoxide. Chromatographic purification gave 2.5 g. 
(49%) of 5-chloro-3-coumaranol: m.p. 85.degree.-86.degree. C.; 
ir(CCl.sub.4) 2.78, 2.94, 3.38, 6.2, 6.78, 10.3.mu.; nmr (CDCl.sub.3) 
.tau. 2.5-3.4 (multiplet, 3 hydrogens, aromatic), 4.92 (multiplet, 1 
hydrogen, --CHOH), 5.76 (multiplet, 2 hydrogens, --CH.sub.2 --), 6.80 
(singlet, 1 hydrogen, OH). 
As described in Example I, Step 2, a solution of 2 g. (0.012 mol.) of 5 
-chloro-3-coumaranol in 8 ml. of dry benzene was allowed to react with a 
solution of 2.2 g. (0.012 mol.) of chrysanthemoyl chloride and 1.9 g. 
(0.024 mol.) of dry pyridine in 10 ml. of dry benzene to yield 2.33 g. 
(61%) of (.+-.) cis,trans-5-chloro-3-coumaranyl chrysanthemate, a viscous 
liquid: ir(film) 3.42, 5.78, 6.2, 6.78, 8.62.mu.; nmr (CCl.sub.4) .tau. 
2.64-3.4 (multiplet, 3 hydrogens, aromatic), 3.9 (multiplet, 1 hydrogen, 
##STR8## 
5.56 (multiplet, 2 hydrogens, --CH.sub.2 --), 8.36 [singlet, 6 hydrogens, 
(CH.sub.3).sub.2 C.dbd.], 8.74, 8.92 [2 singlets, 
In the above procedure, the chrysanthemoyl chloride is replaced by an 
equivalent amount of 3-(2,2-tetramethylene 
ethenyl)-2,2-dimethylcyclopropanecarboxylic acid chloride and 
2,2,3,3-tetramethylcyclopropanecarboxylic acid chloride, respectively, and 
the compounds 5-chloro-3-coumaranyl 3-(2,2-tetramethylene 
ethenyl)-2,2-dimethylcyclopropanecarboxylate and 5-chloro-3-coumaranyl 
2,2,3,3-tetramethylcyclopropane-carboxylate are secured. 
EXAMPLE III 
In the same manner as described in Example I, Step 1, 1.26 g. (0.032 mol.) 
of sodium hydride (as a 61% mineral oil dispersion) and 7 g. (0.032 mol.) 
of trimethyloxosulfonium iodide in 35 ml. of dry dimethyl sulfoxide was 
treated with a solution of 4.56 g. (0.030 mol.) of 
5-methoxysalicylaldehyde in 15 ml. of dimethyl sulfoxide. Chromatographic 
purification gave 1.6 g. (32%) of 5-methoxy-3-coumaranol: ir(neat) 2.98, 
3.4, 6.73, 8.8, 9.74, 10.4.mu.; nmr (CCl.sub.4) .tau. 2.3-3.5 (multiplet, 
aromatic) 4.92 (multiplet, --CHOH), 5.72 (multiplet, --CH.sub.2 --), 6.4 
(singlet, --OCH.sub.3), 7.2 (singlet, --OH). 
As described in Example I, Step 2, a solution of 2 g. (0.012 mol.) of 
5-methoxy-3-coumaranol in 8 ml. of dry benzene was allowed to react with a 
solution of 2.2 g (0.012 mol.) of chrysanthemoyl chloride and 1.9 g. 
(0.024 mol.) of dry pyridine in 10 ml. of dry benzene to yield 2.3 g. 
(61%) of (.+-.) cis, trans- 5-methoxy-3-coumaranyl chrysanthemate as a 
viscous liquid: ir(neat) 3.39, 5.79, 6.18, 6.25, 6.78.mu.; nmr(CCl.sub.4) 
.tau. 2.5-3.6 (multiplet, aromatic), 3.95 (multiplet, 
##STR9## 
6.04 (multiplet, --CH.sub.2 --), 6.4 (singlet, --OCH.sub.3), 8.4 [singlet, 
(CH.sub.3).sub.2 C.dbd.], 8.8, 8.95 [2 singlets, 
##STR10## 
In the above procedure, the chrysanthemoyl chloride is replaced by an 
equivalent amount of 3-(2,2-tetramethylene 
ethenyl)-2,2-dimethylcyclopropanecarboxylic acid chloride and 
2,2,3,3-tetramethylcyclopropanecarboxylic acid chloride, respectively, and 
the compounds 5-methoxy-3-coumaranyl 3-(2,2-tetramethylene 
ethenyl)-2,2-dimethylcyclopropanecarboxylate and 5-methoxy-3-coumaranyl 
2,2,3,3-tetramethylcyclopropanecarboxylalte are secured. 
In the above procedure, the 5-methoxysalicylaldehyde is replaced by an 
equivalent amount of 5-nitrosalicylaldehyde and 5-nitro-3-coumaranyl is 
secured. Esterification of the 5-nitro-3-coumaranyl with the respective 
cyclopropanecarboxylic acid chlorides in the foregoing manner affords 
5-nitro-3-coumaranyl chrysanthemate, 5-nitro-3-coumaranyl 
3-(2,2-tetramethylene ethenyl)-2,2-dimethylcyclopropane carboxylate and 
5-nitro-3-coumaranyl 2,2,3,3-tetramethylcyclopropanecarboxylate, 
respectively. 
Additional compounds encompassed by the present invention can be prepared 
as in Example I by replacing the salicylaldehyde in Step 1 with 
5-methylsalicylaldehyde, 5-ethylsalicylaldehyde, 5-phenylsalicylaldehyde 
and 5-benzylsalicylaldehyde, respectively. Esterification of the resulting 
5-substituted-3-coumaranols with the foregoing cyclopropanecarboxylic acid 
halides yields 5-methyl-3-coumaranyl chrysanthemate; 5-ethyl-3-coumaranyl 
chrysanthemate; 5-methyl-3-coumaranyl 3-(2,2-tetramethylene 
ethenyl)-2,2-dimethylcyclopropane carboxylate; 5-ethyl-3-coumaranyl 
3-(2,2-tetramethylene ethenyl)-2,2-dimethylcyclopropanecarboxylate; 
5-methyl-3-coumaranyl 2,2,3,3-tetramethylcyclopropanecarboxylate; 
5-ethyl-3-coumaranyl 2,2,3,3-tetramethylcyclopropanecarboxylate, and the 
5-phenyl-3-coumaranyl- and 5-benzyl-3-coumaranylchrysanthemates, 
2,2,3,3-tetramethylcyclopropanecarboxylates and 3-(2,2-tetramethylene 
ethenyl)-2,2-dimethylcyclopropanecarboxylates, respectively. 
The outstanding insecticidal properties of the compounds of this invention 
can be seen from the following examples: 
EXAMPLE VI 
3-Coumaranyl chrysanthemate, 5-chloro-3-coumaranyl chrysanthemate, 
5-methoxy-3-coumaranyl chrysanthemate, and natural pyrethrum, 
respectively, were dissolved in acetone and dispersed in distilled water 
with Triton X-100 emulsifier. The samples were applied for a 10 second 
period to houseflies retained in a 2 inches .times. 5 inches diameter 
screened cage. The spray is applied from the Water's vertical spray tower 
operating at 10 p.s.i. and discharging about 30 ml. of material per minute 
through an atomizer. The spray descends through an 8 inches stainless 
steel cylinder to test insects below the atomizer. The insects were 
retained in the sprayed cages for mortality observations. The results are 
set forth in Table 1 below. 
TABLE 1 
______________________________________ 
Housefly Mortality Tests 
Chrysanthemic % Mortality 
Acid Ester % W/V (24 hr.) 
______________________________________ 
3-coumaranol 
0.0025 6 
(Example I) 0.0025 + 0.025 PB* 
93 
0.00125 5 
0.00125 + 0.0125 PB* 
28 
5-chloro-3- 0.005 5 
coumaranol 
(Example II) 
0.005 + 0.05 PB* 99 
0.0025 + 0.025 PB* 
56 
5-methoxy-3- 
0.01 0 
coumaranol 
(Example III) 
0.01 + 0.1 PB* 100 
0.005 + 0.05 PB* 57 
Pyrethrum 0.0025 20 
0.0025 + 0.025 PB* 
96 
0.00125 1 
0.00125 + 0.0125 PB* 
46 
______________________________________ 
*Piperonyl butoxide, an insecticidal synergist, has essentially no 
insecticidal activity at the concentrations reported above. 
In the above test, the respective chrysanthemates are replaced by an 
equivalent amount of 3-coumaranyl 3-(2,2-tetramethylene 
ethenyl)-2-dimethylcyclopropanecarboxylate, 3-coumaranyl 
2,2,3,3-tetramethylcyclopropanecarboxylate, 5-chloro-3-coumaranyl 
3-(2,2-tetramethylene ethenyl)-2,2-dimethylcyclopropanecarboxylate, 
5-chloro-3-coumaranyl 2,2,3,3-tetramethylcyclopropanecarboxylate, 
5-methoxy-3-coumaranyl 3-(2,2-tetramethylene 
ethenyl)-2,2-dimethylcyclopropanecarboxylate, 5-methoxy-3-coumaranyl 
2,2,3,3-tetramethylcyclopropanecarboxylate, 5-nitro-3-coumaranyl 
chrysanthemate, 5-nitro-3-coumaranyl 3-(2,2-tetramethylene 
ethenyl)-2-dimethylcyclopropanecarboxylate, and 5-nitro-3-coumaranyl 
2,2,3,3-tetramethylcyclopropanecarboxylate, respectively, and equivalent 
results are secured. 
EXAMPLE V 
3-Coumaranyl chrysanthemate and natural pyrethrum, respectively, were 
formulated in deodorized kerosene to give a deposit rate of 100 milligrams 
per square foot of area for residual evaluation against houseflies and 200 
and 400 milligrams per square foot of area for residual evaluation against 
German cockroaches. The formulations were uniformly applied at the rate of 
8 milliliters/sq.ft. on unpainted plywood and 3.5 milliliters/sq.ft. on 
vinyl asbestos with a camel hair brush. Adult insects were exposed to each 
treated panel for 1 hour (houseflies) or 2 hours (cockroaches), 
transferred to clean cages, and held for mortality counts. The same 
treated panels were used for re-exposures after the aging period 
indicated. The results were as follows: 
TABLE 2 
______________________________________ 
Residual Activity Against Houseflies 
Surface Age of % Mortality 
Ester Type Residue (Days) 
(24 hr.) 
______________________________________ 
3-coumaranol 
Plywood 1 100 ( 9)* 
(Example I) 3 98 (21) 
7 83 ( 0) 
Vinyl 1 100 (68) 
3 100 ( 0) 
7 59 ( 0) 
______________________________________ 
Residual Activity Against Cockroaches 
Age % 
Surface Milligrams of Residue 
Mortality 
Ester Type per sq. ft. 
(Days) (48 hrs.) 
______________________________________ 
3-coumaranol 
Plywood 400 1 83 (100)* 
(Example I) 
3 83 (100) 
7 90 (100) 
14 73 ( 85) 
200 1 85 (100) 
3 83 (100) 
7 93 ( 95) 
14 85 ( 65) 
Vinyl 400 1 100 (100) 
3 100 (100) 
7 100 (100) 
14 83 (100) 
200 1 100 (100) 
3 95 (100) 
7 70 (100) 
14 20 ( 65) 
______________________________________ 
*The values set forth in parentheses are those secured for pyrethrum whic 
serves as a positive control. 
In the above procedure, the 3-coumaranyl chrysanthemate is replaced by an 
equivalent amount of the 5-ethyl-3-coumaranyl-, 5-methoxy-3-coumaranyl-, 
5-bromo-3-coumaranyl-, 5-thiomethyl-3-coumaranyl-, 5-nitro-3-coumaranyl-, 
5-sulfonylmethyl-3-coumaranyl-, 5-propoxy-3-coumaranyl-, 
5-butoxy-3-coumaranyl-, 5-benzyl-3-coumaranyl-, and 5-phenyl-3-coumaranyl- 
esters of chrysanthemic acid, 3-(2,2-tetramethylene 
ethenyl)-2,2-dimethylcyclopropanecarboxylic acid, and 
2,2,3,3-tetramethylcyclopropanecarboxylic acid, respectively, and 
equivalent results are secured. 
EXAMPLE VI 
3-Coumaranyl chrysanthemate has also been shown to be effective against 11 
other insects as follows. All test species except the webbing clothes moth 
larvae were sprayed in the Water's vertical spray tower as described in 
Example IV. For the fabric tests, a two inch square area of wool fabric 
was dipped in the test formulations. The results secured with various 
insects are set forth below. 
TABLE 3 
______________________________________ 
Insect Mortality Tests 
Test compound 
Pyrethrum + 
% 
+ synergist* 
synergist* Mortality 
Insect (% W/V) (% W/V) (days) 
______________________________________ 
Southern Armyworm 
0.05 + 0.2 70 (2) 
0.05 + 0.2 100 (2) 
Mexican Bean Beetle 
0.005 + 0.02 80 (2) 
0.005 + 0.02 
30 (2) 
Pea Aphid 0.005 + 0.02 65 (2) 
0.005 + 0.02 
100 (2) 
Mite 0.05 + 0.2 69 (5) 
0.05 + 0.2 100 (5) 
German Cockroach 
0.05 + 0.2 30 (2) 
0.05 + 0.2 85 (2) 
Adult mosquito 
0.05 + 0.2 100 (1) 
0.05 + 0.2 100 (1) 
Adult stable flies 
0.05 + 0.2 100 (1) 
0.05 + 0.2 100 (1) 
Black carpet 0.05 + 0.2 40 (7) 
beetle larvae 0.05 + 0.2 40 (7) 
Webbing clothes 
0.05 + 0.2 100 (7) 
moth larvae 0.05 + 0.2 100 (7) 
Adult rice weevils 
0.05 + 0.2 100 (3) 
0.05 + 0.2 100 (3) 
Adult saw toothed 
0.05 + 0.2 100 (3) 
grain beetles 0.05 + 0.2 100 (3) 
______________________________________ 
*Synergist - Piperonyl butoxide 
In the above procedure, the 3-coumaranyl chrysanthemate is replaced by an 
equivalent amount of the 5-ethyl-3-coumaranyl-, 5-methoxy-3-coumaranyl-, 
5-bromo-3-coumaranyl-, 5-thiomethyl-3-coumaranyl, 5-nitro-3-coumaranyl-, 
5-sulfonylmethyl-3-coumaranyl-, 5-propoxy-3-coumaranyl-, and 
5-butoxy-3-coumaranyl- esters of 3-(2,2-tetramethylene 
ethenyl)-2,2-dimethylcyclopropanecarboxylic acid and 
2,2,3,3-tetramethylcyclopropanecarboxylic acid, and the 
5-ethyl-3-coumaranyl-, 5-methoxy-3-coumaranyl-, 5-bromo-3-coumaranyl-, 
5-thiomethyl-3-coumaranyl-, 5-nitro-3-coumaranyl-, 
5-sulfonylmethyl-3-coumaranyl-, 5-propoxy-3-coumaranyl-, and 
5-butoxy-3-coumaranyl- esters of chrysanthemic acid, respectively, and 
equivalent results are secured. 
As can be seen from the foregoing examples, representative compounds of 
this invention possess excellent insecticidal properties, comparing 
favorably with pyrethrum in most aspects and surpassing it in residual 
effect. Additionally, the esters herein are less toxic to mammals than 
pyrethrum as can be seen by the LD.sub.50 values of one of the typical 
esters herein. 
______________________________________ 
Compound LD.sub.50 (rat) 
______________________________________ 
3-coumaranyl chrysanthemate 
&gt;7.57 g./kg. 
Pyrethrum 2.3 g./kg. 
______________________________________ 
The other esters herein are also less toxic than their corresponding 
pyrethrum analogs. 
Insecticidal compositions containing the esters of the present invention 
can be formulated and utilized as oil solutions, emulsifiable 
concentrates, wettable powders, dusts, aerosols, or impregnated into wood, 
fabrics, etc., and provide a long lasting residual effect. Such 
compositions can include the generally employed carriers or diluents and 
auxiliary agents which are well-known to those skilled in the art. For 
example, suitable dusts can be prepared by admixing the compounds of the 
invention with dry free-flowing powders such as clay, bentonite, fuller's 
earth, diatomaceous earth, pyrophyllite, attapulgite, calcium carbonate, 
chalk or the like. The active compounds of the invention normally comprise 
up to about 10% by weight of such dust formulations. An amount of up to 
about 3% is preferred and is suitable for most applications. 
Likewise, suspensions of dispersions of the compounds in a non-solvent, 
such as water, can be suitably employed for the treatment of foilage. Also 
suitably employed are solutions of the insecticides of this invention in 
oil which is emulsified in water. Examples of oil solvents include 
hydrocarbons such as benzene and toluene, halogenated hydrocarbons such as 
chlorobenzene, chloroform, fluorotrichloromethane and 
dichlorodifluoromethane, and commercial mixtures of hydrocarbons such as 
the common Stoddard solvent, petroleum ethers, and the like. 
Aerosols can be prepared by dissolving the compounds of the invention in a 
highly volatile liquid carrier such as trifluorochloromethane, 
nitromethane, dichlorodifluoroethane and the like, or by dissolving such 
compounds in a less volatile solvent, such as benzene or kerosene, and 
admixing the resulting solution with a highly volatile liquid aerosol 
carrier such as the polyfluorohydrocarbons commonly used as aerosol 
propellants. 
The insecticidal esters of this invention are useful for destroying a 
variety of insects. Accordingly, a method aspect of the present invention 
comprises combating insects by applying to said insects, or to an insect 
habitat, an insecticidal amount of one or more of the novel compounds 
disclosed herein. 
Preferably the esters of this invention are employed in combination with a 
synergistic agent, for example, piperonyl butoxide, piperonyl sulfoxide, 
.beta.-butoxy-2'-thiocyanodiethyl ether and the like.