Chromium derivatives as repellents or deterrents to bloodsucking, stinging invertebrates

Description

[0001] This application relates to chromone derivatives as attractants and repellents for blood-sucking biting invertebrates, particularly mosquitoes. This application also relates to compositions that attract or repel blood-sucking biting invertebrates.

[0002] Insects play a vital role in the ecological balance. They are responsible for most plant pollination and are an important link in the food chain. However, some insects are harmful to crops (pests) or even dangerous, as they are vectors of infectious agents for humans and animals. For example, mosquitoes are responsible for the majority of cases of transmission of pathogens that cause infectious diseases. In particular, the species Aedes albopictuswhich is a vector for several arboviruses such as Dengue, Chikungunya, Yellow Fever, and Zika. The most common method for controlling mosquito populations is the application of insecticides, which can be effective but pose significant pollution problems due to their toxicity and broad spectrum of action, which can kill non-target populations (beneficial insects). Furthermore, the emergence of insecticide resistance in vector species makes this approach generally incompatible with sustainable development. The use of repellents to protect exposed populations or attractants for constructing specific traps is increasingly seen as a complement to and / or alternative to the use of insecticides.Relatively effective repellents such as DEET, picaridin, and PMD already exist, but these molecules often have side effects (eye and skin irritation, headaches, respiratory problems) and / or limited effectiveness in terms of protection duration. There are also known attractants (isovaleric acid, 3-octenol, or carbon dioxide, etc.), but these lack selectivity towards mosquitoes and have short durations of activity (Andrianjafy Thesis, 2018, 119, 120p - "Chemical Ecology, an alternative method for controlling disease-carrying mosquitoes (Diptera: Culicidae): bioassay, synthesis, and field evaluation of repellents and attractants." Doctoral thesis at the Doctoral School of Valorization of Renewable Natural Resources, University of Antananarivo).The problem of the duration of activity is important and this parameter is linked to the high volatility of the products used, which are liquids with high vapor pressure. Coumarins are a family of molecules with low vapor pressure with either repulsive or attractive properties (Andrianjafy Thesis. 2018, 110-122p; Andrianjafy). et al.2018). These molecules are effective, but to obtain sufficiently high and selective repellent or attractive effects, it is generally necessary to use mixtures of attractants or repellents (Andrianjafy Thesis 2018, 120-121p; Andrianjafy MT, Ravaomanarivo LH, Vestalys Ramanandraibe V, Rakotomanga MF, Mavingui P, Lemaire M (2018) Synthesis, bioassays and field evaluation of hydroxycoumarins and their alkyl derivatives as repellents or kairomones for Aedes albopictus Skuse (Diptera: Culicidae). J Chem Ecol 44(3):299-311; Becker NM, Zgomba DP, and Ludwig M (1995) Comparison of carbon dioxide, octanol and oa houst-odour as mosquito attractants in the Upper Valley, Germany. Med Vet Entomol 9: 377-380; Hall DR, Beevor PS, Cork A, Nesbitt BF and Vale GA (1984) 1-octen-ol: a potent olfactory stimulant and attractant for tsetse isolated from cattle odors.Insect Sci Appl 5:335-339; Shone SM, Ferrao PN, Lesser CR, Glass GE and Norris DE (2003) Evaluation of carbon dioxide and 1-octen-3-ol-baited centers for disease control Fay-Prince traps to collect Aedes albopictus. J Am Mosq Control Assoc 19:445-447; Govere J, Durrheim DN, Du Toit N, Hunt RH (2000) Local plants as repellents against Anopheles arabiensis, in Mpumalanga Province, South Africa. Cent Afr J Med 46(8):213-6; Barnard DR (2004) Laboratory evaluation of mosquito repellents against Aedes albopictus, Culex nigripalpus, and Ochlerotatus triseriatus (Diptera: Culicidae). Journal of Med Entomol 41:726-730). Moreover, in nature, insects also use mixtures of molecules (semiochemical compounds) to interact with their environment, with each other and with other living beings.It is therefore necessary to search for new molecules capable of selectively interacting with harmful insects in order to prepare repellent formulations (sprays, creams, mosquito nets, clothing, etc.) and attractant formulations (lures, selective traps) to limit host-vector contact and control target insect populations, respectively. US 2012 / 329832 uses coumarins for this purpose.

[0003] The present invention aims to provide a family of compounds exhibiting attractive or repellent properties for blood-sucking biting invertebrates, particularly mosquitoes.

[0004] The present invention also aims to provide attractive or repellent compositions for blood-sucking biting invertebrates, particularly mosquitoes.

[0005] Thus, the present invention relates to the use of a compound with the following formula (I-1): R representing an alkyl group, linear or branched, comprising from 2 to 20 carbon atoms, said compound being achiral when R is a linear group or in the form of a racemic mixture, of an enantiomer ( R ) or an enantiomer ( S ) when R is a branched group, such as attractive or repellent to blood-sucking piercing invertebrates.

[0006] The term "blood-sucking invertebrates" refers to biting invertebrates that feed on blood, including biting insects that attack humans, livestock, or domestic animals.

[0007] According to one embodiment, the blood-sucking piercing invertebrates are chosen from among blood-sucking insects and mites, in particular blood-sucking insects.

[0008] According to a preferred embodiment, blood-sucking biting invertebrates are chosen from the group consisting of mosquitoes, ceratopogonids, phlebotomines, bedbugs, fleas and ticks.

[0009] According to a preferred embodiment, blood-sucking biting invertebrates are selected from mosquitoes of the genera Aedes , Anopheles And Culex.

[0010] According to a preferred embodiment, the blood-sucking biting invertebrates are mosquitoes selected from the group consisting of the following species: Aedes albopictus , Aedes aegypti , Anopheles gambiae sl , Anopheles mascarensis, Anopheles funestus, Anopheles stephensi, Culex pipiens quinquefasciatus And Culex pipiens pipiens.

[0011] According to the invention, a compound attractive to blood-sucking invertebrates is a compound exhibiting attractive properties for blood-sucking invertebrates, i.e., a compound that attracts blood-sucking invertebrates.

[0012] According to the invention, a repellent compound for blood-sucking biting invertebrates is a compound exhibiting repellent properties for blood-sucking biting invertebrates, that is to say, a compound which repels and therefore drives away blood-sucking biting invertebrates.

[0013] In the context of the present invention, the term "alkyl group" means a saturated, linear or branched, aliphatic hydrocarbon group comprising, unless otherwise specified, from 2 to 20 carbon atoms. Examples include ethyl, n-propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, nonyl, and decyl groups.

[0014] According to one embodiment, in the aforementioned formula (I-1), R represents an alkyl group, linear or branched, comprising from 4 to 20 carbon atoms.

[0015] According to one embodiment, in the aforementioned formula (I-1), R represents an alkyl group, linear or branched, comprising from 4 to 16, in particular from 4 to 10, carbon atoms.

[0016] As stated above, when R is a linear group in the formula (I-1) as defined above, the corresponding compound does not have an asymmetric carbon and is therefore an achiral compound.

[0017] When R is a branched group in formula (I-1) as defined above, the corresponding compound is then in the form of a racemic mixture, an enantiomer ( R ) or an enantiomer ( S ).

[0018] The present invention also relates to the use of a compound of the following formula (II): R' representing a linear alkyl group comprising from 2 to 18 carbon atoms, said compound being in the form of a racemic mixture of an enantiomer ( R ) or an enantiomer ( S), as an attractant or repellent to blood-sucking, piercing invertebrates.

[0019] According to an embodiment not included in the claimed invention, the aforementioned use of a compound of formula (III) may be envisaged: in which: either R1 is H or a methyl group and R2 represents an alkyl group comprising 3 to 18 carbon atoms, or R2 is H or a methyl group and R1 represents an alkyl group comprising 3 to 18 carbon atoms, as an attractant for blood-sucking, piercing invertebrates, said compound being in the form of a racemic mixture of an enantiomer ( R ) or an enantiomer ( S ).

[0020] The present invention also relates to the aforementioned use of a compound of formula (II): in which R' represents an alkyl group comprising from 3 to 18 carbon atoms, as attractive to blood-sucking biting invertebrates, said compound being in the form of a racemic mixture, an enantiomer (R) or an enantiomer ( S ).

[0021] According to an embodiment not included in the claimed invention, the aforementioned use of a compound of formula (II-1) may be envisaged: in which R" represents a linear alkyl group comprising from 4 to 20 carbon atoms, as attractive to blood-sucking, piercing invertebrates, said compound being in the form of a racemic mixture of an enantiomer ( R ) or an enantiomer (S).

[0022] The present invention also relates to the use of a compound of formula (II) as defined above, in which R' represents an alkyl group comprising 2 carbon atoms, as a repellent for blood-sucking biting invertebrates, said compound being in the form of a racemic mixture of an enantiomer ( R ) or an enantiomer ( S ).

[0023] According to one embodiment, the compound of formula (II) for the aforementioned use is in the form of the enantiomer ( R ) or a racemic mixture.

[0024] According to one embodiment, the compound of formula (II) for the aforementioned use is in the form of the enantiomer ( S ), and the compound is used in a composition in which the content of said compound is greater than or equal to 20% by weight relative to the total weight of said composition.

[0025] The present invention also relates to the aforementioned use of a compound of formula (II) as an attractant for blood-sucking biting invertebrates, in which R' represents an alkyl group comprising 2 carbon atoms, said compound being in the form of the enantiomer ( S ), and in which the compound is used in a composition in which the content of said compound is less than or equal to 20% by weight relative to the total weight of said composition.

[0026] The following compounds may be mentioned in particular as examples of compounds of formula (I-1) used according to the invention: 7- dry -butoxychromone; 7- dry -pentoxychromone; 7-sec-nonyloxychromone; 7-R-(-)- dry -butoxychromone; 7-S-(+)-sec-butoxychromone; R-(-)-sec-pentoxychromone; 7-n-decyloxychromone and 7-(2'-ethyl)hexyloxychromone.

[0027] The present invention also relates to compositions comprising the aforementioned compounds of formula (I-1), (II), (III) or (II-1), exhibiting attractive or repulsive properties.

[0028] The present invention also relates to an attractive or repellent composition for blood-sucking, biting invertebrates, comprising at least one compound of formula (I-1) as defined above, said compound being in the form of a racemic mixture of an enantiomer ( R ) or an enantiomer ( S ), said composition possibly further comprising an additional compound attractive or repellent to a blood-sucking, piercing invertebrate.

[0029] The present invention also relates to an attractive composition for blood-sucking, biting invertebrates as defined above, comprising: at least one compound of formula (I-1) as defined above, wherein R represents an alkyl group comprising from 2 to 16 carbon atoms, preferably from 5 to 10 carbon atoms, or at least one compound of formula (I-1) as defined above, wherein R represents an alkyl group comprising 4 carbon atoms, said compound being in the form of the enantiomer ( S ), and in which the compound is in the form of the enantiomer ( S ) is used in a content less than or equal to 20% of said composition.

[0030] The present invention also relates to an attractive composition for blood-sucking, biting invertebrates as defined above, comprising: at least one compound of formula (II) as defined above, wherein R' represents an alkyl group comprising from 3 to 18 carbon atoms, preferably from 3 to 10 carbon atoms, or at least one compound of formula (II) as defined above, wherein R' represents an alkyl group comprising 2 carbon atoms, said compound being in the enantiomer form ( S ), and in which the compound is in the form of the enantiomer ( S ) is used in a content less than or equal to 20% of said composition.

[0031] The present invention also relates to a repellent composition for blood-sucking, biting invertebrates as defined above, comprising: at least one compound of formula (I-1) in which R represents an alkyl group comprising 4 carbon atoms, the compound of formula (I-1) being in the form of the enantiomer ( R ) or a racemic mixture, or a mixture of enantiomers (R ) And ( S ) in mass contents other than 50 / 50%; or at least one compound of formula (I-1) in which R represents an alkyl group comprising 4 carbon atoms, said compound being in the enantiomer form ( S ) and in which said compound is in the form of the enantiomer ( S ) is used in a content greater than or equal to 1% by weight relative to the weight of said composition.

[0032] The present invention also relates to a repellent composition for blood-sucking, biting invertebrates as defined above, comprising: at least one compound of formula (II) in which R' represents an alkyl group comprising 2 carbon atoms, the compound of formula (I) being in the form of the enantiomer ( R ) or a racemic mixture, or a mixture of enantiomers ( R ) And ( S) in mass contents other than 50 / 50%; or at least one compound of formula (II) in which R' represents an alkyl group comprising 2 carbon atoms, said compound being in the enantiomer form ( S ) and in which said compound is in the form of the enantiomer ( S ) is used in a content greater than or equal to 1% by weight relative to the weight of said composition.

[0033] According to one embodiment, the repellent compositions according to the invention are in the form of a spray or cream, a support, for example a textile support or nets, or cartridges for diffusers.

[0034] According to one embodiment, the compositions of the invention are compositions that are attractive or repellent to mosquitoes selected from the group consisting of the following species: Aedes albopictus, Aedes aegypti, Anopheles gambiae sl , Anopheles mascarensis, Anopheles funestus , Anopheles stephensi , Culex pipiens quinquefasciatus And Culex pipiens pipiens.

[0035] The compositions of the invention may further include an additional compound that is attractive or repellent to a blood-sucking invertebrate. This combination further enhances the attractive or repellent properties of the composition of the invention.

[0036] For example, an attractive composition of the invention may comprise the attractive molecule 4-hydroxycoumarin, in association with a compound of formula (I-1) or (II), (II-1) or (III) as defined above. Such a combination is synergistic and enhances the attractive properties of compound (I-1), (II), (II-1) or (III) compared to a composition comprising only compound (I-1), (II), (II-1) or (III).

[0037] The present invention also relates to a kit for trapping a blood-sucking, biting invertebrate, in particular a mosquito, and in particular Aedes albopictus, including: at least one attractive composition comprising at least one compound of the following formula (I-1): R representing an alkyl group, linear or branched, comprising from 2 to 20 carbon atoms, said compound being achiral when R is a linear group or in the form of a racemic mixture, of an enantiomer ( R ) or an enantiomer ( S ) where R is a branched group, said composition possibly further comprising an additional compound attractive to a blood-sucking invertebrate, and at least one trap for a blood-sucking invertebrate, in particular a mosquito, and in particular Aedes albopictus.

[0038] The present invention also relates to a kit for trapping a blood-sucking, biting invertebrate as defined above, wherein the attractive composition comprises: at least one compound of formula (I-1), in which R represents an alkyl group comprising from 2 to 16 carbon atoms, or at least one compound of formula (I-1), in which R represents an alkyl group comprising 4 carbon atoms, said compound being in the form of the enantiomer (S), and in which the compound in the form of the enantiomer (S) is used in a content less than or equal to 20% of said composition.

[0039] The traps used according to the invention are those well known to a person skilled in the art.

[0040] Examples of traps include the BG sentinel trap (Biogent®) and the CDC light trap for capturing Aedes sp. and Anopheles sp., respectively.

[0041] The present invention also relates to the use of the aforementioned kit for trapping blood-sucking biting invertebrates, particularly mosquitoes, in particular Aedes albopictus And Anopheles sp.

[0042] The present invention also relates to a repellent support for blood-sucking biting invertebrates, particularly mosquitoes, and in particular Aedes albopictus, said support being impregnated with at least one repellent composition comprising: at least one compound with the following formula (I-1): in which R represents an alkyl group comprising 4 carbon atoms, the compound of formula (I) being in the form of the enantiomer ( R ) or a racemic mixture, or a mixture of enantiomers ( R ) And ( S ) in mass contents other than 50 / 50%; or at least one compound of formula (I) in which R represents an alkyl group comprising 4 carbon atoms, said compound being in the enantiomer form ( S ) and in which said compound is in the form of the enantiomer ( S) is used in a content greater than or equal to 20% by weight in relation to the weight of said composition, said composition possibly also including an additional repellent compound for a blood-sucking biting invertebrate, said support being in particular chosen from the group consisting of textiles, in particular mosquito nets, clothing for hiking, bracelets, necklaces or cartridges for diffusers.

[0043] Such a repellent support is prepared by impregnating a support as defined above with a repellent composition according to the invention as defined above. This impregnation step can be carried out, for example, by spraying or dipping. FIGURES

[0044] There Figure 1 represents the synergistic effect between the compounds 4-hydroxycoumarin and 7-nonyloxychromone with respect to Aedes albopictus.It represents the IK (in %) as a function of the amount deposited (in mg). The curve with the diamonds corresponds to 4-hydroxycoumarin, the curve with the squares corresponds to 7-nonyloxychromone, and the curve with the triangles corresponds to the synergy. Figure 2 represents the IK (in %) as a function of the amount deposited (in mg) for 7-n-decyloxychromone with respect to of Aedes albopictus. There Figure 3 represents the IK (in %) as a function of the amount deposited (in mg) for 7-(2'-ethyl)hexyloxychromone with respect to Aedes albopictus. EXAMPLES MATERIALS AND METHODS SYNTHESIS OF CHROMONE DERIVATIVES

[0045] 7-Hydroxy-4-chromone is used as the starting material to obtain the ether derivatives. The synthesis is carried out based on the effect of the molecule's structure on mosquito behavior. 1. Synthesis by phase transfer catalysis

[0046] The reaction with a phase-transfer catalyst is used for the synthesis of non-chiral products as shown below: Example 1 Summary of section 7 dry -racemic butoxychromone (1CPT)

[0047] In a 250 mL three-necked reflux reactor equipped with a magnetic stirrer and a thermometer, 100 mL of toluene and 8.4 g of K₂CO₃ (61 mmol) are added, followed by 2 g of 7-hydroxychromone (12 mmol) and 10.14 g of 2-bromobutane (82 mmol). For the phase-transfer catalyst, 0.1 g of tetrabutyl ammonium hydrogen sulfate is added. The mixture is stirred under reflux for 6 h at 120°C, and the organic phase is collected by decantation, washed with distilled water, dried with Na₂SO₄, and then evaporated. The resulting oily mixture is purified by silica gel column chromatography (ethyl 2-hexane acetate eluent). The pure product is obtained as a yellow oil with a yield of 73%. Example 2 Summary of section 7 dry -racemic pentoxychromone (2CPT)

[0048] In a 250 mL three-necked reflux reactor equipped with a magnetic stirrer and a thermometer, 100 mL of toluene and 4.2 g of K₂CO₃ (30.6 mmol) are added, followed by 1 g of 7-hydroxychromone (6.15 mmol) and 5 g of 2-bromopentane (41.2 mmol). For the phase-transfer catalyst, 0.05 g of tetrabutyl ammonium hydrogen sulfate is added. The mixture is stirred under reflux for 6 h at 120°C, and the organic phase is collected by decantation, washed with distilled water, dried with Na₂SO₄, and then evaporated. The oily mixture is purified by silica gel column chromatography (ethyl 2-hexane acetate eluent). The pure product is obtained as a yellow oil with a yield of 33.1%. Example 3 Synthesis of racemic 7-sec-nonyloxychromone (3CPT)

[0049] In a 250 mL three-necked reflux reactor equipped with a magnetic stirrer and a thermometer, 100 mL of toluene and 2.13 g of K₂CO₃ (15.3 mmol) are added. Then, 0.5 g of 7-hydroxychromone (3.1 mmol) and 3 g of 2-bromononane (20.6 mmol) are added to the mixture. For the phase-transfer catalyst, 0.025 g of tetrabutyl ammonium hydrogen sulfate is added. The mixture is stirred under reflux for 6 h at 120°C, and the organic phase is collected by decantation, washed with distilled water, dried with Na₂SO₄, and then evaporated. The oily mixture is purified by silica gel column chromatography (ethyl 2-hexane acetate eluent). The pure product is obtained as a yellow oil with a yield of 35.2%. Example 4 Synthesis of 7-isopropyloxychromone (4CPT)

[0050] In a sealed 15 mL tube equipped with a magnetic stirrer and a thermometer, 7 mL of toluene and 0.8 g of K₂CO₃ (5.8 mmol) are added, followed by 0.25 g of 7-hydroxychromone (1.54 mmol) and then 2 g of 2-bromopropane (16.26 mmol). As a phase-transfer catalyst, 0.4 g of tetrabutyl ammonium hydrogen sulfate is added. The mixture is stirred for 24 hours at 90°C, and the organic phase is collected by decantation, washed with distilled water, dried with Na₂SO₄, and then evaporated. The oily mixture is purified by silica gel column chromatography (ethyl 2-hexane acetate eluent). The pure product is obtained as white solids with a yield of 29.4%. 2. Synthesis by the Mitsunobu reaction

[0051] The Mitsunobu reaction is used to selectively transform an alcohol into different functional groups, such as ether, in a single step. This reaction also allows for the enantio-inversion of chiral alcohols, as shown below: Example 5 Summary of the R -(-)- dry -butoxychromone (5M)

[0052] In a 50 mL reactor equipped with a thermometer, a magnetic stirrer, and a slight nitrogen overpressure, 15 mL of dichloromethane, 1 g of 7-hydroxychromone (6.2 mmol), then 1.2 mL of S-butan-2-ol (12.4 mmol), and 3.2 g of triphenylphosphine (12.4 mmol) are added sequentially. The mixture is then stirred for a few minutes, and 2.2 mL of DEAD (diethyl azodicarboxylate) solution (24 mmol) is added dropwise. The reaction is carried out at room temperature for 15 to 24 hours. The solution is then evaporated, and the mixture is purified by silica gel column chromatography (ethyl 2-hexane acetate eluent). The pure product is obtained as a pale yellow oil with a yield of 52.6%. Example 6 Summary of the S -(+)- dry -butoxychromone (6M)

[0053] In a 50 mL reactor equipped with a thermometer, a magnetic stirrer, and a slight nitrogen overpressure, 30 mL of dichloromethane, 2 g of 7-hydroxychromone (12.4 mmol), then 2.4 mL of R-butan-2-ol (24.6 mmol), and 6.4 g of triphenylphosphine (24.6 mmol) are added sequentially. The mixture is then stirred for a few minutes, and 4.2 mL of DEAD solution (24 mmol) is added dropwise. The reaction is carried out at room temperature for 15 to 24 hours. The solution is then evaporated, and the mixture is purified by silica gel column chromatography (ethyl 2-hexane acetate eluent). The pure product is obtained as a pale pink oil with a yield of 53%. Example 7 : Summary of the ( R 7- dry -pentoxychromone (7M)

[0054] In a 50 mL reactor equipped with a thermometer, a magnetic stirrer, and a slight nitrogen overpressure, 30 mL of dichloromethane, 1 g of 7-hydroxychromone (6.2 mmol), then 1.4 mL of S-pentan-2-ol (12.3 mmol), and 3.23 g of triphenylphosphine (12.3 mmol) are added sequentially. The mixture is then stirred for a few minutes, and 2.1 mL of DEAD solution (12.3 mmol) is added dropwise. The reaction is carried out at room temperature for 15 to 24 hours. The solution is then evaporated, and the mixture is purified by silica gel column chromatography (ethyl 2-hexane acetate eluent). The pure product is obtained as a pale pink oil with a yield of 63.3%. Example 8 : Summary of the ( S ) 7-sec-pentoxychromone (8M)

[0055] In a 50 mL reactor equipped with a thermometer, a magnetic stirrer, and a slight nitrogen overpressure, 30 mL of dichloromethane, 1 g of 7-hydroxychromone (6.2 mmol), then 1.4 mL of R-pentan-2-ol (12.3 mmol), and 3.23 g of triphenylphosphine (12.3 mmol) are added sequentially. The mixture is then stirred for a few minutes, and 2.1 mL of DEAD solution (12.3 mmol) is added dropwise. The reaction is carried out at room temperature for 15 to 24 hours. The solution is then evaporated, and the mixture is purified by silica gel column chromatography (ethyl 2-hexane acetate eluent). The pure product is obtained as a pale yellow oil with a yield of 42.4%. Example 4bis Summary of section 7 n -decyloxychromone (5CPT)

[0056]

[0057] In a 50 mL three-necked reflux reactor equipped with a magnetic stirrer and a thermometer, 10 mL of toluene and 0.691 g of K₂CO₃ (5 mmol) are added. Then, 0.2 g of 7-hydroxychromone (1 mmol) and 0.660 g of 1-bromodecane (3 mmol) are added to the mixture. For the phase-transfer catalyst, 0.05 g of tetrabutyl ammonium hydrogen sulfate is added. The mixture is stirred under reflux for 3 h at 120°C, and the organic phase is recovered by decantation, washed with distilled water, dried with Na₂SO₄, and then evaporated. The oily mixture is purified by liquid-liquid partition extraction (hexane and distilled water). The pure product is obtained as a white solid (pf = 45°C) with a yield of 66%. Example 4ter Synthesis of 7-(2'-ethyl)hexyloxychromone

[0058]

[0059] In a 50 mL three-necked reflux reactor equipped with a magnetic stirrer and a thermometer, 10 mL of toluene and 0.691 g of K₂CO₃ (5 mmol) are added, followed by 0.2 g of 7-hydroxychromone (1.2 mmol) and 0.580 g of 1-bromo-2-ethylhexane (3 mmol). For the phase-transfer catalyst, 0.02 g of tetrabutyl ammonium hydrogen sulfate is added. The mixture is stirred under reflux for 6 h at 120°C, and the organic phase is collected by decantation, washed with distilled water, dried with Na₂SO₄, and then evaporated. The crude mixture is purified by silica gel column chromatography (hexane / ethyl acetate 98 / 2 eluent). The pure product is obtained as a yellow oil with a yield of 65%. CHEMICAL ANALYSIS

[0060] The 1<H and 13<C NMR spectra of the synthesized products are obtained with the BRUKER spectrometer.

[0061] An ATAGO POLAX-D polarimeter is used to determine the optical rotations of chiral products with a 2 dm observer tube. The products are diluted in 0.2% ethanol. EVALUATION OF THE REPULSIVE AND / OR ATTRACTANT EFFECT OF CHROMONE ETHERS IN A TUNNEL OLFACTOMETER

[0062] The tunnel olfactometer is a glass parallelepiped 1 meter long and 5 x 5 cm on each side. The tube has three openings: two on each side for inserting paper impregnated with the product to be tested, and one for paper containing a control. The middle opening allows for the introduction of mosquitoes. Both ends of the device are closed with lids.

[0063] The olfactometer is divided into three compartments or zones: a neutral zone which is in the middle; a test or treated zone which is on the product deposition side; and a control zone which is on the control deposition side.

[0064] For each test, 15 females Aedes albopictusMosquitoes aged 5 to 12 days were introduced into the neutral zone of the tunnel olfactometer. They were held for 10 minutes for an acclimatization period. Papers impregnated and dried with a product solution in ethanol and pure ethanol (as a reference) were then introduced, and the barriers were opened to allow the mosquitoes to move freely within the device. Three test replicates were performed for each product. Each replicate lasted 20 minutes, and the observed results were recorded every 5 minutes.

[0065] The recorded values ​​are the activity index and the repellency index. The activity index (AI) describes the percentage of mosquitoes found in the control area (T) and the treated area (P) relative to the total number of mosquitoes tested. This value must be greater than 30% for the test to be considered statistically significant.

[0066] The repellent index (RI) represents the percentage difference between the number of mosquitoes in the control and treated areas, divided by the sum of these two values. A negative value for the parameter (RI) indicates an attractiveness (Kairomone index, KI) of the tested product. IA = T + P 15 ∗ 100 IR = T − P T + P ∗ 100 AI: Activity index; IR: Repellency index; T: Number of mosquitoes in the control area; P: Number of mosquitoes in the treated area RESULTS SYNTHESIS OF CHROMONE DERIVATIVES 1. Synthesis by phase transfer catalysis

[0067] Five products were synthesized based on the length of the alkyl chain: 7-sec-butoxychromone, 7-sec-pentoxychromone, 7-sec-nonyloxychromone, 7-isopropyloxychromone, and 7-decyloxychromone. The results obtained are illustrated in Table 1. Table 1. Results obtained from the synthesis of non-chiral chromone ethers by phase-transfer catalysis reaction Entrance Haloalkane Product obtained Pure yield Appearance 1 CPT 2-bromobutane 7-sec-butoxychromone 73% Yellow oil 2 CPT 2-bromopentane 7-sec-pentoxychromone 33,1% Yellow oil 3 CPT 2-bromononane 7-sec-nonyloxychromone 35,2% Yellow oil 4 CPT 2-bromopropane 7-isopropyloxychromone 29,4% Solid white 5 CPT 1-bromodecane 7-n-decyloxychromone 66% Solid yellow 2. Synthesis by the Mitsunobu reaction

[0068] Four enantiomers were synthesized: the R -(-)- dry -butoxychromone, the S -(+)- dry- butoxychromone, the R -(-)- dry -pentoxychromone and the S -(+)- dry -pentoxychromone. Table 2 shows the results obtained during the synthesis reactions. Table 2. Results obtained from the synthesis of chiral products by the Mitsunobu reaction Entrance Chiral alcohol Product obtained Optical rotation (0.2% in EtOH) Pure yield Appearance 5 M ( S ) butan-2-ol R -(-)- dry- butoxychromone -35 52,6% Pale yellow oil 6 M ( R ) butan-2-ol S -(+)- dry- butoxychromone +35 53% Pale pink oil 7 M ( R ) pentan-2-ol R -(-)- dry- pentoxychromone -22,5 63,3% Pale pink oil 8 M ( S ) pentan-2-ol S -(+)- dry- pentoxychromone +22.5 42.4% Pale pink oil CHEMICAL ANALYSIS OF PRODUCTS BY NUCLEAR MAGNETIC SPECTROMETRY (NMR) 7- dry -butoxychromone racémique (1CPT)

[0069] NMR 1< H (300 MHz) in CDCl 3: 8.11 (1H, d, H 5 ), 7.77 (1H, d, H 2 ), 6.96 (1H, dd, H 6 ), 6.82 (1H, s, H 8 ), 6.26 (1H, d, H 3 ), 4.41 (1H, m, H 11 ), 1.77 (2H, m, H 13), 1.36 (3H, d, H 12), 1 (3H, t, H 14) NMR 13< C in CDCl 3: 177.05, 162.90, 158.31, 154.83, 127.18, 118.40, 115.49, 112.83, 101.82, 75.82, 28.99, 9.68 Yield = 73% (Pale yellow oil) 7- dry -pentoxychromone (2CPT)

[0070] RMN 1< H (300 MHz) dans CDCl 3 : 8.13 (1H, d, H 5 ), 7.75 (1H, d, H 2 ), 6.9 (1H, dd, H 6 ), 6.8 (1H, s, H 8 ), 6.28 (1H, d, H 3 ), 4.5 (1H, m, H 11 ), 1.75 (2H, m, H 13 ), 1.6 (3H, d, H 12 ), 1.38 (2H, m, H 14 ), 0.90 (3H, t, H 15 ) RMN 13< C dans CDCl 3 : 177.03, 162.90, 158.31, 154.79, 127.19, 118.40, 115.45, 112.84, 101.75, 74.42, 38.31, 19.44, 18.64, 13.95 Rendement = 33.1% (Huile jaune pâle) 7- dry -nonyloxychromone (3CPT)

[0071] RMN 1< H (300 MHz) dans CDCl 3 : : 8.09 (1H, d, H 5 ), 7.75 (1H, d, H 2 ), 6.93 (1H, dd, H 6 ), 6.8 (1H, s, H 8 ), 6.28 (1H, d, H 3 ), 4.46 (1H, m, H 11 ), 1.76 (2H, m, H 13 ), 1.62 (3H, d, H 12 ), 1.41 (2H, m, H 18 ), 1.34 (2H, t, H 17 ), 1.34 (2H, t, H 16 ), 1.28 (2H, t, H 15 ), 1.28 (2H, t, H 14 ), 0.87 (3H, t, H 19 ) RMN 13< C dans CDCl 3 : 177, 162.88, 158.30, 154.77, 127.18, 118.40, 115.44, 112.84, 101.77, 74.69, 36.18, 31.75, 29.46, 29.18, 25.40, 22.61, 19.45, 14.05 Yield = 35.2% (Pale yellow oil) 7-isopropyloxychromone (4CPT)

[0072] NMR 1< H (300 MHz) in CDCl 3: 8.09 (1H, d, H 5 ), 7.76 (1H, d, H 2 ), 6.93 (1H, dd, H 6 ), 6.8 (1H, s, H 8 ), 6.26 (1H, d, H 3 ), 4.64 (1H, m, H 11 ), 1.35 (3H, d, H 12), 1.35 (3H, d, H 13), NMR 13< C in CDCl 3: 176.98, 162.52, 158.27, 154.77, 127.15, 118.43, 115.43, 112.84, 101.81, 70.73, 21.77 Yield = 29.4% (White solid) 7-decyloxychromone

[0073] RMN 1< H (300 MHz) dans CDCl 3 : 8.02 (1H, d, H 5 ), 7.68 (1H, d, H 2 ), 6.89 (1H, dd, H 6 ), 6.75 (1H, d, H 8 ), 6.20 (1H, d, H 3 ), 3.87-3.85 (2H, d, H 11 ), 1.72 (1H, m, H 12 ), 1.49 (2H, m, H 13 ), 1.39(2H, m, H 17 ), 1.26 (2H,m, H 16 ), 1.19 (2H, m, H 15 ), 0.90(3H, m, H 14 ), 0.85 (3H, m, H 18 ), RMN 13< C dans CDCl 3 : 177.98 (C 4 ), 164.24 (C 7 ), 158.49 (C 10 ), 155.60 (C 2 ), 126.79 (C 5 ), 118.08 (C 9 ), 115.32 (C 3 ), 112.34 (C 6 ), 100.78 (C 8 ), 71.21 (C 11 ), 39.15 (C 12 ), 30.36 (C 15 ), 28.95 (C 16 ), 23.72 (C 13 ), 22.88 (C 17 ), 13.83 (C 18 ), 10.88 (C 14 ) 7-(2'-ethyl)hexyloxychromone

[0074] NMR 1< H (300 MHz) in CDCl 3: 8.03 (1H, d, H 5 ), 7.68 (1H, d, H 2 ), 6.84 (1H, dd, H 6 ), 6.75 (1H, d, H 8 ), 6.20 (1H, d, H 3 ), 3.87-3.85 (2H, d, H 11 ), 1.72 (1H, m, H 12 ), 1.49 (2H, m, H 13 ), 1.39 (2H, m, H 17 ), 1.26 (2H, m, H 16 ), 1.19 (2H, m, H 15 ), 0.90 (3H, m, H 14 ), 0.85 (3H, m, H 18 ), NMR 13< C in CDCl 3: 177.98 (C 4 ), 164.24 (C 7 ), 158.49 (C 10 ), 155.60 (C 2 ), 126.79 (C 5 ), 118.08 (C 9 ), 115.32 (C 3 ), 112.34 (C 6 ), 100.78 (C 8 ), 71.21 (C 11 ), 39.15 (C 12 ), 30.36 (C 15 ), 28.95 (C 16 ), 23.72 (C 13 ), 22.88 (C 17 ), 13.83 (C 18 ), 10.88 (C 14) EVALUATION OF THE REPULSIVE AND / OR ATTRACTANT EFFECT OF CHROMONE ETHERS IN A TUNNEL OLFACTOMETER Chromone derivatives with repellent properties against Aedes albopictus Example 9 : Evaluation of racemic 7-sec-butoxychromone (1CPT)

[0075] The results obtained for the evaluation of repellent or attractive activity against Aedes albopictus with the racemic compound 7-sec-butoxychromone are described in Table 3 for product doses corresponding to 5, 10, 30 and 60 mg / ml. Table 3. t-test dry- Comparison of average mosquito numbers in the two areas: control and treated. Activity index and repellent index for 7-butoxychromone. Dose (mg / ml) Product (±SD) Control (±SD) t p-value AI (%) IR (%) 5 3,3 ± 0,1 7,3 ± 0,4 -12,8 0,0002 71,1 37,6 10 3,6 ± 0,4 7,2 ± 0,9 -4,52 0,01 71,8 37,9 30 3,4 ± 0,9 8,3 ± 0,5 -5,43 0,006 78 56,1 60 1,8 ± 0,2 11,8 ± 0,7 -16,5 <0,0001 90,6 72,9 Example 10 : Evaluation de la R -(-)-sec-butoxychromone (5M)

[0076] The results obtained for the evaluation of repellent or attractive activity against Aedes albopictus with compound 7- dry -racemic butoxychromone are described in Table 3 for product doses corresponding to 5, 10, 30 and 60 mg / ml. Table 4. t-test R dry- Comparison of average mosquito numbers in the two areas: control and treated. Activity index and repellency index for -(-)-butoxychromone. Dose (mg / ml) Treated (±SD) Control (±SD) t p-value AI (%) IR (%) 5 3,1 ± 0,1 9,5 ± 0,3 -25,12 < 0,0001 84 51,3 10 2,3 ± 0,7 11 ± 0,3 -16,4 < 0,0001 88,9 65,6 30 1,4 ± 0,1 12,4 ± 0,1 -93,3 < 0,0001 92,2 79,5 60 1,6 ± 0,2 12,2 ± 0,1 -66,7 < 0,0001 92 76,6 Example 11 : Evaluation de la S-(+)- dry -butoxychromone (6M)

[0077] The results obtained for the evaluation of repellent or attractive activity against Aedes albopictus with the racemic compound 7-sec-butoxychromone are described in Table 5 for product doses corresponding to 5, 10, 30 and 60 mg / ml. Table 5. t-test S dry- Comparison of average mosquito numbers in the two areas: control and treated. Activity index and repellency index for -(+)-butoxychromone. Dose (mg / ml) Treated (±SD) Control (±SD) t p-value AI (%) IR (%) 5 9,0 ± 0,2 4,8 ± 0,5 10,4 0,0004 91,7 -31,2 10 8,9 ± 1,1 4,2 ± 0,9 4,03 0,016 87,2 -35,8 30 3,3 ± 0,2 9,3 ± 0,8 -8,8 0,001 83,3 47,9 60 2,0 ± 0,0 11,4 ± 0,8 -15,6 < 0,0001 89,4 70,5

[0078] The activity indices are very high (>70%), indicating that the results are reliable. The racemic and compound ( R ) are repellent regardless of the dose. Compound (S) is attractive at low doses and repellent at high doses. This reversal of effect has already been observed with certain coumarins.

[0079] It is noted that the racemic has an effect corresponding approximately to the average of the effects of the two enantiomers. Example 12 Comparison of (R) 7-sec-butoxychromone with picaridin and DEET

[0080] We now compare the repulsive properties of ( R 7- dry -butoxychromone with those of known repellents at equivalent doses of 10 and 30 mg / ml we observe that this new repellent is as effective as and more effective than Picaridin and DEET which are considered the most effective products on the market. Table 6. Comparison of the effects of (R) 7-sec-butoxychromone with DEET and picaridin. Repulsion index: 5 mg deposit Repulsion index: 10 mg deposit Repulsion index, 30 mg deposit ( R ) 7- dry- butoxychromone 51% 65.6% 79.5% DEET 55.5% 60.4% 59.1% Picardin 42.6% 49.6% 59.7% Chromone derivatives with attractive properties towards Aedes albopictus

[0081] Obtaining products that attract harmful insects is equally important, as it allows for the manufacture of selective and effective traps for dangerous insects. Certain substituted chromones have demonstrated attractive activity.

[0082] The syntheses of these compounds are carried out using the same processes as for 7-sec-butoxychromones: by phase-transfer catalysis for the racemic and by Mitsunobu reaction for the enantiomers. R And S . Example 13 : Evaluation of the 7- dry -pentoxychromone racemic or (+ / -) (2CPT)

[0083] The results obtained for the evaluation of the attractiveness of the activity with respect to Aedes albopictus with compound 7- dry -racemic pentoxychromone are described in Table 7 for product doses corresponding to 1, 5, 10 and 30 mg / ml. Table 7. t-test 7-sec- Comparison of average mosquito numbers in the two areas: control and treated. Activity index and repellency index for pentoxychromone. Dose (mg / ml) Treated (±SD) Control (±SD) t p-value AI (%) IK (%) 1 9,3 ± 0,7 3,5 ± 0,5 8,49 0,001 85 -45,6 5 9,5 ± 0,2 2,5 ± 0,3 23,5 < 0,0001 80,1 -59,2 10 9,8 ± 1,1 3,4 ± 0,4 6,8 0,002 88,3 -47,9 30 8,7 ± 0,4 4,8 ± 0,4 8,5 0,001 90 -28,6 Example 14 : Evaluation de la (R) 7-sec-pentoxychromone (6M)

[0084] The results obtained for the evaluation of the attractiveness of the activity with respect to Aedes albopictus with the compound ( R 7- dry -racemic pentoxychromone are described in Table 8 for product doses corresponding to 1, 5, 10 and 30 mg / ml. Table 8. t-test R dry- Comparison of average mosquito numbers in the two areas: control and treated. Activity index and repellent index for pentoxychromone. Dose (mg / ml) Treated (±SD) Control (±SD) t p-value AI (%) IK (%) 1 8,6 ± 0,2 5,3 ± 0,3 10 0,001 92,2 -24,3 5 10,8 ± 0,6 2,2 ± 0,4 14,7 0,001 86,7 -66,6 10 8,6 ± 0,1 3,6 ± 0,4 16 < 0,0001 81,1 -47,1 30 6,9 ± 0,3 6,6 ± 0,4 0,89 0,42 90 -2,8 Example 15 : Evaluation de la ( S ) 7- dry -pentoxychromone (7M)

[0085] The results obtained for the evaluation of the attractiveness of the activity with respect to Aedes albopictus with the compound ( S 7- dry -racemic pentoxychromone are described in Table 9 for product doses corresponding to 1, 5, 10 and 30 mg / ml. Table 9. t-test S dry- Comparison of average mosquito numbers in the two areas: control and treated. Activity index and repellency index for -(+)-pentoxychromone. Dose (mg / ml) Treated (±SD) Control (±SD) t p-value AI (%) IK (%) 1 10,3 ± 0,7 3,8 ± 0,3 10,3 0,0004 93,3 -46,3 5 9,5 ± 0,7 3,1 ± 1,2 5,9 0,004 83,9 -52,4 10 8,4 ± 0,1 5,8 ± 0,2 13,8 0,0001 95 -18,2 30 6,5 ± 0,7 5,2 ± 0,3 2,15 0,09 77,8 -10,7

[0086] The two enantiomers R, S and the racemic form of 7-pentoxychromone are attractive to Aedes albopictus. The effect of the racemic product appears to be cumulative, combining the effects of the two pure enantiomers.

[0087] We observe a bell-shaped curve, as seen with known kairomones (isovaleric acid, 1-octen-3-ol) (Andrianjafy et al. 2017). Example 16 : Evaluation de la 7- dry -nonyloxychromone (3CPT)

[0088] 7-sec-nonyloxychromone was evaluated in a tunnel olfactometer at doses of 2 to 30 mg / ml. The results are presented in Table 10. Table 10. t-test dry- Comparison of average mosquito numbers in the two areas: control and treated. Activity index and repellent index for 7-nonyloxychromone. Dose (mg / ml) Treated (±SD) Control (±SD) t p-value AI (%) IK (%) 0.1 11,2 ± 0,6 2,5 ± 0,2 19,6 < 0,0001 91,1 -63,5 2 12,3 ± 0,0 1,4 ± 0,4 29,8 < 0,0001 91,1 -79,8 5 10,4 ± 0,1 2,2 ± 0,3 35 < 0,0001 83,9 -65,8 10 11,3 ± 0,0 2,5 ±0,5 15,1 0,0001 91,7 -63,6 30 8.4 ± 0.2 4.8 ± 0.4 10.4 0.0004 88,3 -27,1

[0089] As with 7-sec-pentoxychromone, a bell-shaped curve is obtained with a maximum IK value close to 80% at a dose of 2 mg / ml. Attractiveness remains above 65% up to 10 mg / ml. Even at high doses (30 mg / ml), 7-nonyloxychromone remains attractive. And considering that the vapor pressure of this product should be low due to its high molecular weight, the duration of effectiveness will be long. Example 17 : Evaluation of the attractive properties of 7-n-decyloxychromone towards Aedes albopictus

[0090] The results obtained for the evaluation of the attractiveness of the activity with respect to Aedes albopictus with the racemic compound 7-n-decyloxychromone are presented in Table 11 for the corresponding product dose of 10 mg / ml. Dose (mg / ml) Treated (±SD) Control (±SD) THERE IS (%) CI (±SD) (%) 10 8,8 ± 0,9 3,9±0,3 85 -37,8±5,2

[0091] 7-N-Decyloxychromone has an attractive effect equivalent to that of 7-sec- nonyloxychromone but has the advantage of being much less expensive (inexpensive primary halide and bio-based). Example 18 Comparison of 7- dry -pentoxychromone and 7-sec-nonyloxychromone with octen-3-ol

[0092] We now compare the attractive properties of racemics 7-sec- pentoxychromone and 7-sec-nonyloxychromone with octen-3-ol. Table 12 . dry dry Comparison of 7-pentoxychromone and 7-nonyloxychromone with octen-3-ol Repulsion Index Deposit 5mg Repulsion Index Deposition 10 mg Repulsion Index Deposition 30 mg 7- dry- pentoxychromone -59,2% -47,8% -28,7% 7- dry- nonyloxychromone -65,8% -63,7% -27,1% Octen-3-ol -41,7% -54,7% -61,6%

[0093] Analysis of the results on alkoxy chromones shows an attractant activity equivalent to that of octenol. However, it is known that octenol has a high vapor pressure, unlike alkoxy chromones, which can therefore have a longer-lasting effect.

[0094] The results above show that the compounds of the invention have significant attractive or repulsive properties on Aedes albopictus depending on the structure of the substituent (chain length, stereochemistry,...).

[0095] Unlike hydroxyl or methoxy groups, 2-butoxy groups produce significant repellent effects that are dependent on the stereochemistry of the 2-butoxy chain. The repellent effect of the R enantiomer is as strong as that of DEET and picaridin at identical doses.

[0096] Secondary alkoxy groups higher than butyl (pentyl and nonyl) lead to products with high molecular weights and attractive properties. The attractive effect also depends on the stereochemistry of the 2-alkoxy group. Similarly, chromones with long-chain primary alkoxy substituents (e.g., decyl) have a very high attractive effect. And when compared to the most commonly used attractant (octenol) at the same doses, alkoxychromones exhibit a higher attractive effect.

[0097] With 7-butoxychromones, it is possible to formulate protective sprays, creams and textiles containing the products alone or in mixture with other repellent products.

[0098] With attractive products, traps (mechanical, materials impregnated with glues, etc.) baited with products alone or mixed with other attractants allow for mass trapping of mosquitoes and other blood-sucking insects.

[0099] These 7-hydroxychromone derivatives have the advantage of high molecular weights, allowing them to have a long duration of effectiveness in terms of repulsion and attraction towards of Aedes albopictus. Example 19 Evaluation of repulsive properties in a caged olfactometer

[0100] The long-term evaluation (24 hours) is carried out in a cage system (1m x 1m x 2m) equipped with two traps, one baited and the other a control. The tests are conducted in parallel in two experimental rooms (3.5m x 2m x 2m) maintained at 25 + / - 5°C, 60% relative humidity, for a 12-hour photoperiod (Andrianjafy). et al. 2017). Inside the large cage is placed a smaller cage (35 cm × 35 cm × 35 cm) containing the mosquitoes before release, as well as two traps (one with the product being tested and the other with the control). These traps are separated by 1.45 m. For the tests, 100 µl of the solutions are placed on filter paper using ethanol as the solvent. The ethanol is evaporated before being placed in the trap. A CO2 source is placed outside the cage to increase mosquito activity. 25 females Aedes albopictus are used for each test, which lasts 24 hours and begins at 9 a.m. Six replications are performed for each dose of a product. > 24-hour cage test for the repellent properties of ( R 7- dry- butoxychromone. > 24-hour cage test for the attractive properties of ( RS 7- dry- nonyloxychromone. > Test in nature with a "sentinel" trap of the racemic ( RS 7- dry- nonyloxychromone. > Test of synergistic effects for the attractive properties of ( RS 7- dry- nonyloxychromone and 4-hydroxycoumarin Example 20 Tests with traps

[0101] Tests in nature » of a compound or mixture according to the invention are carried out with the BG sentinel trap (Biogent®) and the CDC light trap to capture Aedes sp. and Anopheles sp., respectively. The results obtained are conclusive. Example 21 Evaluation of the combination of a compound of the invention with a chromone compound

[0102] It is possible to associate a chromone compound with other compounds of different structures. For example, 4-hydroxycoumarin is a selective attractant. of Aedes albopictus, The use of a 50 / 50 mixture of 4-hydroxycoumarin and 7-(2-nonyloxy)chromone has a greater attractive power than the two compounds used separately.

[0103] 7-Nonyloxychromone exhibits attractiveness at low doses (or quantities), with a Kairomone Index (IK) of 57%. A significant decrease in this effect is observed starting at a dose of 10 mg. Similarly, 4-Hydroxycoumarin also demonstrates attractiveness at low doses, with an IK of approximately 40%. A 10% increase in attractiveness was recorded for higher doses (10 and 30 mg).

[0104] A synergistic effect is observed between 4-hydroxycoumarin and 7-nonyloxychromone (cf. Figure 1This effect is generally relatively independent of concentration, unlike pure products, with an IK > 55% for all tested doses, which is a significant practical advantage. We hypothesize that 4-hydroxycoumarin (appearance: solid) stabilizes 7-nonyloxychromone (appearance: liquid) to generate a stronger attractant effect. Example 22 : Evaluation of 7-n-decyloxychromone and 7-(2'-ethyl)hexyloxychromone

[0105] The evaluation of the attractive properties of 7-n-decyloxychromone and 7-(2'-ethyl hexyloxychromone) was carried out in a tunnel olfactometer by varying the quantity of product to be tested, according to the protocol described above.

[0106] THE Figures 2 And 3 represent the results thus obtained.

Claims

1. The use of a compound with formula (I-1): R being a linear or branched alkyl group comprising from 2 to 20 carbon atoms, said compound being achiral when R is a linear group or in the form of a racemic mixture, an enantiomer (R) or an enantiomer (S) when R is a branched group, as an attractant or repellent for blood-sucking, biting invertebrates, preferentially for mosquitoes, in particular of the genera Aedes, Anopheles and Culex, or alternatively ceratopogonidae, phlebotominae, bugs, fleas and ticks.

2. The use according to claim 1 of a compound with the formula (II): wherein R' represents an alkyl group containing 3 to 18 carbon atoms, as an attractant for blood-sucking, biting invertebrates.

3. The use according to claim 1 of a compound with the formula (II): wherein R' represents an alkyl group containing 2 carbon atoms, as a repellent for blood-sucking, biting invertebrates.

4. The use according to claim 3, wherein the compound with the formula (II) is in the form of the enantiomer (R) or a racemic mixture, or wherein the compound with the formula (II) is in the form of the enantiomer (S), and wherein the compound is used in a composition wherein the content of said compound is greater than or equal to 20% by weight with respect to the total weight of said composition.

5. The use according to claim 2 of a compound with the formula (II) as attractant for blood-sucking, biting invertebrates, wherein R' represents an alkyl group comprising 2 carbon atoms, said compound being in the form of the enantiomer (S), and wherein the compound is used in a composition wherein the content of said compound is less than or equal to 20% by weight with respect to the total weight of said composition.

6. An attractant or repellent composition for blood-sucking, biting invertebrates comprising at least one compound of the following formula (I-1): R being a linear or branched alkyl group comprising from 2 to 20 carbon atoms, said compound being achiral when R is a linear group or in the form of a racemic mixture, an enantiomer (R) or an enantiomer (S) when R is a branched group, said composition optionally further comprising an additional compound which is attractant or repellent for a blood-sucking, biting invertebrate.

7. The attractant composition for blood-sucking, biting invertebrates according to claim 6, comprising: - at least one compound with the formula (I-1), wherein R represents an alkyl group comprising from 2 to 16 carbon atoms, or - at least one compound with the formula (I-1), wherein R represents an alkyl group comprising 4 carbon atoms, said compound being in the form of the enantiomer (S), and wherein the compound in the form of the enantiomer (S) is used in a concentration smaller than or equal to 20% of said composition.

8. The repellent composition for blood-sucking, biting invertebrates according to claim 6, comprising: - at least one compound with the formula (I-1) wherein R represents an alkyl group containing 4 carbon atoms, the compound with the formula (I-1) being in the form of the enantiomer (R) or of a racemic mixture, or of a mixture of the enantiomers (R) and (S) in mass concentrations different from 50 / 50%; or - at least one compound with the formula (I-1) wherein R represents an alkyl group comprising 4 carbon atoms, said compound being in the form of the enantiomer (S) and wherein said compound in the form of the enantiomer (S) is used in a concentration greater than or equal to 20% by weight with respect to the weight of said composition, said composition being in particular in the form of a spray or cream, a support or cartridges for diffusers.

9. A kit for trapping blood-sucking, biting invertebrate, in particular Aedes albopictus, comprising: at least one attractant composition comprising at least one compound of the following formula (I-1): R being a linear or branched alkyl group comprising from 2 to 20 carbon atoms, said compound being achiral when R is a linear group or in the form of a racemic mixture, an enantiomer (R) or an enantiomer (S) when R is a branched group, - said composition optionally further comprising an additional compound which is attractant for a blood-sucking, biting invertebrate, and at least one blood-sucking, biting invertebrate trap, in particular Aedes albopictus.

10. A kit for trapping blood-sucking, biting invertebrate according to claim 9, wherein the attractant composition comprises: - at least one compound with the formula (I-1), wherein R represents an alkyl group comprising from 2 to 16 carbon atoms, or - at least one compound with the formula (I-1), wherein R represents an alkyl group comprising 4 carbon atoms, said compound being in the form of the enantiomer (S), and wherein the compound in the form of the enantiomer (S) is used in a concentration smaller than or equal to 20% of said composition.

11. The use of the kit according to claims 9 or 10 for trapping blood-sucking, biting invertebrates, in particular mosquitoes, more particularly Aedes albopictus and Anopheles sp.

12. A repellent support for blood-sucking, biting invertebrates, in particular Aedes albopictus, said support being impregnated with at least one repellent composition comprising: - at least one compound with the following formula (I-1): wherein R represents an alkyl group containing 4 carbon atoms, the compound with the formula (I-1) being in the form of the enantiomer (R) or of a racemic mixture, or of a mixture of the enantiomers (R) and (S) in mass concentrations different from 50 / 50%; or - at least one compound with the formula (I-1) wherein R represents an alkyl group comprising 4 carbon atoms, said compound being in the form of the enantiomer (S) and wherein said compound in the form of the enantiomer (S) is used in a concentration greater than or equal to 20% by weight with respect to the weight of said composition, said composition optionally further comprising an additional compound which is attractant for a blood-sucking, biting invertebrate, said support being chosen in particular from the group consisting of textiles, in particular mosquito nets, clothing for hiking, bracelets, necklaces or cartridges for diffusers.