USE FOR CONIFER SAPLING PROTECTION

Abstract: The present invention relates to the use of at least one compound with formula (I), for conifer sapling protection. It also relates to the use of a composition for conifer sapling protection.

Description: Use for conifer sapling protection The present invention relates to the use of at least one compound for conifer sapling protection. It also relates to the use of a composition for conifer sapling protection. Background of the invention The pine weevil, Hylobius abietis, kills through its gnawing on the bark a large proportion of the conifer saplings that are planted after felling. The damage costs Swedish forestry hundreds of millions Swedish crowns yearly (Weslien 1998). The pine weevil is, therefore, one of the economically most important insects in Sweden. The species is known as a serious noxious insect in large parts of Europe and Asia. In North America there are some closely related species with a similar way of living (Hylobius pales, Hylobius congener, and Pachylobhis picivorus). The damage by the pine weevil could to a certain degree be reduced by a fallow period, soil scarification and regeneration beneath shelterwood trees. The fallow period should be avoided because of production loss and problems with competing vegetation. Soil scarification and regeneration beneath shelterwood are silvicultural methods that currently are further developed, and that in many areas could be included as a part of the management of the pine weevil problem (Orlander & Nord- lander 1998). However, further protection of the saplings is needed in most places. Different ways of mechanical protection are presently tested but there is not yet any method really working in practice (Orlander & Petersson 1998). Since a long time, the pine weevil problem has mainly been managed by immersion or spraying the saplings with a relatively persistent insecticide (LangstiOm 1998). At present, the synthetic pyrethroid permethrin is allowed for this purpose in Sweden. However, the Swedish National Chemicals Inspectorate has the intention to prohibit this treatment of saplings after the year 2004 because of environmental reasons. Possibly the other Nordic countries will also follow this example. Therefore, it is very urgent to find alternatives to protection treatment with insecticides. Some alternatives to insecticides have been described in the literature such as insect repellents and the use thereof. For example, Viktorov-Nabokov (1980) describes methyl-4-hydroxybenzoate as a blood sucking mosquito repellent. SE 7709013-2 describes the use of a composition comprising halogen substituted phenols and phenol ethers designed for conifer sapling protection against noxious insects. No publications describe the use of the compounds according to the invention for conifer sapling protection. We have analysed the methanol extracts of the faeces of Hylobius abietis by GC- MS and pyrolysis GC-MS. Comparison of the mass spectra obtained, with the spectra in the Finnigan Nist library indicated that the unknown chemical structures were substance 15 and 22 or closely related analogues (see below). Further separation of the extracts from the faeces by column chromatography gave a polar fraction with high biological activity. The function of this signal substance is probably that gnawing where a female has laid eggs should be avoided, whereby the eggs should not be destroyed. Moreover, laboratory tests have shown that also several similar substances have a more or less gnawing-inhibiting effect. The toxicity of these substances is low. The risk of resistance development towards the substances is insignificant due to the fact that saplings constitute a small part of the pine weevil diet (Nordlander 1998). Summary of the invention The present invention relates to the use of at least one compound for conifer sapling protection. It also relates to the use of a composition for conifer sapling protection. Detailed description of the invention One object of the present invention is the use of at least one compound for conifer sapling protection, characterised in that the compounds are selected from the fol- lowing compounds with Formula I: Formula I wherein Ri, R 2 , R 3 , R 4 , and R 5 each independently stand for - hydrogen; - hydroxy; - a Cι-Cι 2 -alkyl group, preferably a Cι-C 8 -alkyl group, more preferably a Cι-C 6 - alkyl group, optionally substituted with one or more halogen, hydroxy or -C 12 alkoxy groups, preferably Cp -alkoxy groups, more preferably C C 6 -alkoxy groups; most preferably wherein the Cι-Cι 2 -alkyl group is a methyl group; - a Cι-Cι -alkoxy group, preferably a C C 8 -alkoxy group, optionally substituted with one or more halogen, hydroxy or Cι-Cι -alkoxy groups, preferably Cj-C 8 - alkoxy groups, more preferably Ci-Cδ-alkoxy groups; most preferably wherein the Cι-Cι 2 -alkoxy group is a methoxy, piperonyl or n-octyloxy group, - a nitro group; or - halogen, preferably chloro or bromo; R' stands for - a Cι-Cι 2 -alkyl group, preferably a Cι-C 8 -alkyl group, more preferably a C[-C 6 - alkyl group, optionally substituted with one or more halogen, hydroxy or Cι-Cι 2 - alkoxy groups, preferably C C 8 -alkoxy groups, more preferably Cι-C 6 -alkoxy groups, most preferably wherein the CrCι 2 -alkyl group is a 1-propenyl or a 2- propenyl group; - a hydroxy substituted Cι-C !2 -hydrocarbon group, preferably a hydroxy substituted CrCβ-hydrocarbon group, more preferably a hydroxy substituted C C 3 - hydrocarbon group, most preferably a hydroxymethyl or a 3 -hydroxy -n-propyl group; - a methylcarboxylic group, preferably a methylcarboxylic acid or a methylcar- boxylic Ci-C 6 -ester group, more preferably a methylcarboxylic acid group; or - C(0)XR " , wherein - X stands for a heteroatom; and - R " stands for - hydrogen; - a C[-Cι 2 -alkyl group, optionally substituted with one or more deuterium, halogen, hydroxy, aryl, optionally substituted with one or more C i -C h alky 1 groups, preferably Cι-C -alkyl groups, more preferably Cι-C 6 -alkyl groups, C Cι 2 -alkoxy groups, preferably C C 8 -alkoxy groups, more pref- erably -C ό -alkoxy groups, or Cι-Cι 2 -alkoxy groups, preferably C C 8 - alkoxy groups, more preferably CpC 6 -alkoxy groups, most preferably wherein the Cι-Cι -alkyl group is a methyl, ethyl, trideuteriomethyl, 2,2,2- rrifluoroethyl, isopropyl, 3-(3,4-dimethoxyphenyl)-n-propyl, (E)-3-n- hexenyl or a n-dodecyl group; or - an aryl group, optionally substituted with one or more -Cι -alkyl groups, preferably Cι-C 8 -alkyl groups, more preferably Cι-C 6 -alkyl groups, Cι-Cι 2 -alkoxy groups, preferably Cι-C 8 -alkoxy groups, more preferably -C ό -alkoxy groups, most preferably wherein the aryl group is a 2- methoxy-4-(2-propenyl)pheny 1 group ; as well as esters and salts thereof. Another object of the present invention is the use of a composition for conifer sapling protection, characterised in that it comprises at least one of the following compounds with Formula I: Formula I wherein Ri, R , R , R- ! , R 5 , and R ' are as defined above, pure or in a solvent, with or without a suitable carrier such as wood, cellulose, wood-flour, straw, cork, cane, lignin, lig- nocellulose, rubber, gum, leather or skin, milled carbon, fats or waxes of animal, vegetable, or synthetic origin, natural resins of animal or vegetable origin, plastic, organic polymers such as polyvinyl acetate, polyaciylates, polyvinyl chloride, chlorinated polyethylene, polyols such as polyethylene glycol, synthetic or natural latexes, silicone polymers or resins, silicates, pumice, silica, or any mixture thereof. A suitable solvent is selected from the group consisting of Ci-Cδ-alkohols and C C ό -alkyl esters of Cι-C 6 -alkanoic acids, preferably methyl acetate, methanol, and isopropanol. As used in this application: a) the term "Cι-Cι -alkyl" refers to a saturated or unsaturated, straight or branched chained alkyl radical containing from 1 to 12 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, 1-propenyl, 2-propenyl, n-butyl, isobutyl, t-butyl, 1- butenyl, 2-butenyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n- undecyl, n-dodecyl etc; For parts of the range "Cι-Cι 2 -alkyr all subgroups thereof are contemplated such as d-Cn-alkyl, C,-Cι 0 -alkyl, C,-C 9 -alkyl, C r C 8 -alkyl, C C 7 -alkyl, C,-C 6 -alkyl, Cι-C 5 -alkyl, C C -alkyl, C C 3 -alkyl, Cι-C 2 -alkyl, etc; b) the term "halogen" refers to a fluoro, chloro, bromo or iodo group; c) the term "Cι-Cι 2 -alkoxy" refers to a saturated or unsaturated, straight or branched chained alkoxy radical containing from 1 to 12 carbon atoms, such as methoxy, ethoxy, ethenoxy, n-propoxy, isopropoxy, 1-n-propenoxy, n-butoxy, isobutoxy, t- butoxy, n-pentoxy, n-hexoxy, n-heptoxy, n-octoxy, n-nonoxy, n-decoxy, n- undecoxy, n-dodecoxy, etc; For parts of the range "Cι-Cι 2 -alkoxy" all subgroups thereof are contemplated such as Ci-C i i -alkoxy, CpCio-alkoxy, -Cg-alkoxy, Cj-C 8 -alkoxy, Cι-C 7 - alkoxy, Cι-C 6 -alkoxy, -Cs-alkoxy, Cι-C -alkoxy, C C 3 -alkoxy, C C -alkoxy, etc; d) the term "hydroxy substituted CpCι 2 -hydrocarbon group" refers to a saturated or unsaturated, straight or branched acyclic hydrocarbon radical containing one or more hydroxyl groups and containing 1 to 12 carbon atoms, such as hydroxymethyl, 1-hydroxyethyl, 2-hydroxyethyl, 1-hydroxy-n-propyl, 2-hydroxy-n- propyl, 3-hydroxy-n-propyl, 1-hydιoxyisopropyl, 2-hydroxyisopropyl, 1- hydroxy-n-prop-2-enyl, 1-hydroxy-n-butyl, 2-hydroxy-n-butyl, 1 -hydroxy -n-but- 2-enyl, l-hydroxy-n-but-3-enyl, 1 -hydroxy -n-pentyl, 5 -hydroxy -n-penta- 1,3- dienyl, 1-hydroxy-n-hexyl, 1,3-dihydroxy-n-hexyl, 1,5-dihydroxy -n-hexyl, 1- hydroxy-n-heptyl, 1-hydroxy-n-octyl, 1-hydroxy-n-nonyl, 1-hydroxy-n-decyl, 1- hydroxy-n-undecyl, 1-hydroxy-n-dodecyl, etc; For parts of the range "C Cι 2 -hydrocarbon" all subgroups thereof are contemplated such as CpC ii -hydrocarbon, C Cιo-hydrocarbon, Ci-Cg-hydrocarbon, C C 8 -hydrocarbon, Cι-C 7 -hydrocarbon, C C 6 -hydrocarbon, Cι-C 5 -hydrocarbon, Cι-C 4 -hydrocarbon, C C 3 -hydrocarbon, C C 2 -hydrocarbon, etc; e) the term "methylcarboxylic group" refers to a methylcarboxylic acid, a methylcarboxylic Cι-C 6 -ester or a methylcarboxylic C 0 -C 6 -amide group; f) the term " methylcarboxylic Ci-C 6 -ester" refers to a saturated or unsaturated, straight or branched alkyl ester of a methylcarboxylic acid group and wherein the ester portion contains 1-6 carbon atoms, such as methylcarbomethoxy, methyl- carbethoxy, 1-methylcarbopropoxy, 2-methylcarbopropoxy, 2- methylcarbopropenoxy, 1-methylcarbobutoxy, 1-methylcarbopentoxy, 1- methylcarbohexoxy, etc; g) the term " methylcarboxylic Co-C 6 -amide" refers to a saturated or unsaturated, straight or branched primary, secondary or tertiary amide of a methylcarboxylic acid group and wherein the amide portion contains 0-6 carbon atoms, such as methylcarboxamide, N-methyl-methylcarboxamide, N,N-dimethyl- methylcarboxamide, N-ethyl-methylcarboxamide, N-(n-propyl)- methylcarboxamide, N-isopropyl-methylcarboxamide, N-methyl, N-isopropenyl- methylcarboxamide, N-(n-pentyl)-methylcarboxamide, N-(n-hexyl)- methylcarboxamide, etc.; h) the term C(O) refers to a carbonyl; i) the term "heteroatom" refers to an oxygen, nitrogen, sulphur, etc; j) the term "aryl group" refers to a phenyl, naphthyl, anthracene, etc.; k) the term "C C 6 -alcohoι" refers to a saturated or unsaturated, straight or branched alkyl alkohol and containing 1-6 carbon atoms, such as methanol, ethanol, n- propanol, isopropanol, n-butanol, tert-butanol, 1-butenol, n-pentanol, n-hexanol, etc; and 1) the term "C C 6 -alkyl ester of a Ci-C ό -alkanoic acid " refers to a saturated or unsaturated, straight or branched alkyl ester and containing 1-6 carbon atoms of a saturated or unsaturated, straight or branched alkanoic acid and containing 1-6 carbon atoms, such as methyl formiate, ethyl formiate, isopropyl formiate, iso- propenyl formiate, methyl acetate, ethyl acetate, ethyl propionate, ethyl butyrate, ethyl valerate, ethyl hexanoate, etc. It should be noted that both E- and Z-isomers of the compounds, optical isomers, as well as mixtures thereof, and all isotopes are included within the scope of the invention. By the expression "isotopes" is meant all compounds with naturally occur- ring isotopes such as all possible deuterium and 13 C-isotopes of the compounds according to the invention. It should be noted that both esters and salts of the compounds according to the in- vention are included within the scope of the invention. As examples of esters of the compounds are intended e.g. methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl and n-pentyl esters. As examples of salts of the compounds are intended in particular environmentally acceptable acid and base addition salts. The expression "environmentally acceptable acid addition salts" are intended to be any non-toxic organic or inorganic acid addition salt of the base compounds with the formula I. Examples of illustrative inorganic acids that form suitable salts are hydrochloric acid, hydrobromic acid, sulphuric acid, phosphoric acid and acid metal salts such as sodium monohydrogen ortophosphate and potassium hydrogensul- phate. Examples of illustrative organic acids that form suitable salts are mono-, di- and tricarboxylic acids. Examples of such acids are acetic acid, glycolic acid, lactic acid, pyruvic acid, malonic acid, succinic acid, glutaric acid, fumaric acid, malic acid, tartaric acid, citric acid, ascorbic acid, maleic acid, hydroxymaleic acid, ben- zoic acid, hydroxybenzoic acid, phenylacetic acid, cinnamic acid, salicylic acid, 2- phenoxybenzoic acid, and sulphonic acids such as p-toluenesulphonic acid, methanesulphonic acid and 2-hydroxyethanesulphonic acid. Such salts could either be in hydrated or anhydrous form. The acid addition salts of these compounds are generally water soluble and different hydrophilic organic solvents and, that compared to the free base forms thereof, generally display higher melting points. The expression "environmentally acceptable base salts" are intended to be any non- toxic organic or inorganic base addition salt of the base compounds with the formula I. Examples of illustrative inorganic bases that form suitable salts are alkali and earth alkali metal hydroxides and carbonates such as sodium hydroxide, sodium carbonate, potassium hydroxide, potassium carbonate, calcium hydroxide, calcium carbonate, magnesium hydroxide, magnesium carbonate and ammonia. Examples of illustrative organic bases that form suitable salts are methylamine, dimethylamine, trimethylamine and picoline. Either mono- or dibasic salts could be formed with such compounds. The base addition salts of these compounds are generally water soluble and different hydrophilic organic solvents and, that compared to the free base forms thereof, generally display higher melting points. Examples of compounds with Formula I are listed below i e the compounds 3-88. 3 Homovanillic acid 4 3 -(4-hydroxy-3 -methoxyphenyl )- 1 -propanol 5 3-(3,4-dimethoxyphenyl)-l-propanol 10 3,5-dimethoxybenzyl alcohol 12 methyl 11 methyl 2,4-dihydroxy- 3 , 4-di hy droxyb enzoate benzoate 14 methyl 2-hydroxy-4-methoxy- 13 methyl 3,5-dihydroxybenzoate b enzoate 15. methyl 3,4-dimethoxy¬ 17. 3-(3,4-dimethoxyphenyl)-n-propyl 3,5-dimethoxybenzoate 18. 2-hydroxy-3-methoxybenzoic acid 19. 2-hydroxy-5-methoxybenzoic acid 0 3-hydroxy-4-methoxybenzoic acid 21 3,4-dimethoxybenzoic acid 31 methyl 3,4,5- 32 methyl 3,4,5- tπ m eth ox b enzoate tri hydroxy b enzoate 35. 3,5-dimethoxy-4-hydroxybenzoic acid 39. piperonylic acid 49. methyl 3-chloro- 50. methyl 2-hydroxy-3-methoxybenzoate 4-methoxybenzoate 51. methyl 4-hydroxy-3-rnethoxybenzoate 2 methyl 2-hydroxy-5-methoxybenzoate 53 methyl 3-hydroxy-4-methoxybenzoate 54 methyl 2,3-dimethoxybenzoate 60 isoeugenol 61 eugenol 62 methylisoeugenol methyleugenol 64 3,5-dimethoxyphenylacetic acid 70 isopropyl 4-hydroxyb enzoate 71 methyl 4-n-octyloxybenzoate methyl 2-hydroxybenzoate 73 methyl 2,4-dihydroxy-3,6-dimethylbenzoate 80 methyl 3,5-dibromobenzoate 81 methyl 3, 5-dinitrobenzoate 82. 3,5-dimethoxybenzoic acid 83. N-ethyl 3,5-dimethoxybenzamide 84. ethylthionyl 3,5-dimethoxybenzoate 85. 2,2,2-trifluoroethyl 3,5-dimetoxybenzoate 86. (E)-3-n-hexenyl 3,5-dimetoxybenzoate 87. trideuteriom ethyl 3,5-dimethoxybenzoate 88. 2-methoxy-4-(2-propenyl)phenyl 3,5-dimethoxybenzoate In Table 1 is given a catalogue number for some of the compounds according to the invention and the supplier thereof, wherein the expressions "Aldrich" relates to the catalogue number of the Aldrich order catalogue, and "Lancaster" relates to the catalogue number of the Lancaster order catalogue. Table 1. Catalogue number for compounds according to the invention. Some of the other compounds of the invention were synthesised as described in Example 1. Another object of the present invention relates to the use for conifer sapling protection against insects, characterised in that the insect species belong to the beetle (Coleoptera) family Curculionidae (including subfamilies Curculioninae and Scoly- tinae), particularly species of the genera Hylobius, Pachylobius and Hylastes, spe- cifically the species Hylobius abietis, Hylobius pmastri, Hylobius pales, Hylobius congener, Pachylobius pictvorus, Hylastes brunneus and Hylastes cuniculanus. By the expression "comprising" we understand including but not limited to. Thus, other non-mentioned substances, additives or carriers may be present. The invention will be illuminated by the followmg Examples, which are only intended to illuminate and not restrict the invention in any way. Examples Experimental The chemicals were obtained from Lancaster Syntheses Ltd or Aldrich. Medium pressure liquid column chromatography (MPLC) was earned out on silica gel (Merck 60, 0.040-0.063 mm) in 15 or 25 inner diameter (i.d.) glass columns. Gradient elution with hexane and increasing amounts of ethyl acetate was done as described by Baeckstrom 1987. TLC was performed on silica gel (Merck 60, HF pre- coated aluminium foil) using 40% ethyl acetate in hexane as the eluent. The plates were developed with vanillin and H 2 S0 4 in ethanol. NMR spectra were recorded in CDC1 3 on an AM 400 spectrometer. GCMS analyses. Mass spectra were recorded at 70 eV using a Finnigan SSQ 7000 GC-MS instrument connected with a Varian 3400 GC. Injections were made in a splitless mode for 30 seconds at 200°C using helium as the carrier gas. The instrument was equipped with a DB-5 fused silica capillary column (J&W 30 m, i.d. 0.25 mm, film thickness 0.25 μm) Insects. The insects used for the experiments was the pine weevil (Hylobius abietis) taken from their natural environment, i e coniferous forests. Preparation of gnawing-inhibiting compositions. The compositions are prepared by incorporating the compounds in a suitable matrix. When the compounds are not soluble in the matrix a solvent such as methanol or isopropanol is used to transfer the compounds into the matrix. At most 0.5 g per sapling of the compounds is needed. A used ratio is 40 g compound, 20 g carrier e.g. a polyol, and 80 ml of a solvent. Chemicals. The compounds 5, 11, 13, 14, 15, 18, 19, 20, 21, 22, 31, 32, 33, 35, 39, 50, 52, 53, and 64 could be purchased from the Sigma-Aldrich Sweden AB, Solk- raftsv. 14c, 135 70 Stockholm, Sweden. The compounds 3, 10, 12, 49, 51, 60, 61, 62, 63, 70, 71, 72, 73, 80, 81, and 82 could be purchased from Lancaster Synthesis Ltd, Eastgate, White Lund, Morecambe, Lancashire LA3 3DY, UK. Example 1 - Synthesis of compounds according to the invention The compounds 4, 16, 17, 30, 34, 83, 84, 85, 86, 87, and 88 were synthesised according to the procedures described for each compound: Compound 4 - 3 -(4-hydroxy-3 -methoxyphenyl)- 1 -propanol 3-(4-hydroxy-3-methoxyphenyl)-l-propanoic acid (200 mg, 1.02 mmol) was converted to 3 -(4-hydroxy-3 -methoxyphenyl)- 1 -propanol (103 mg) by reaction with 150 mg of LiAlH 4 . The yield was 56%. 1H NMR: 6.82 (d, J = 7.6 Hz, IH), 6.68 (m, 2H), 3.85 (s, 3H), 3.67 (t, J = 6.4 Hz, 2H), 2.63 (t, J = 7.3 Hz, 2H), 1.85 (quint., 2H) and 13 C NMR 146.4 (Ar-C), 143.7 (Ar-C), 133.7 (Ar-C), 120.9 (Ar-C), 114.3 (Ar-C), 111.0 (Ar-C), 62.2 (OMe), 55,8 (CH 2 OH), 34.4 (ArCH 2 ), 31.7 (CH 2 ). Compound 16 - n-dodecyl 3,4-dimethoxybenzoate n-dodecanol (3.84 mmol) was added to a stirred solution of dicyclohexylcarbodi- imide (1.19 g, 5.77 mmol), 4-(dimethylamino)pyridine (0.038 g, 0.31 mmol) and 3,5-dimethoxybenzoic acid (5.77 mmol) in dry CH 2 CI 2 (8.5 ml) (Kato 1985). The mixture was stirred at room temperature for 12 h, and then diluted with hexane (2 ml). The mixture was filtered and the solid material was washed with CH 2 C1 2 . The combined filtrate and washings were concentrated in vacuo and then subjected to silica gel chromatography. n-dodecyl 3,4-dimethoxybenzoate was analysed by NMR and mass spectroscopy. Compound 17 - 3-(3,4-dimethoxyphenyl)-n-propyl 3,5-dimethoxybenzoate 3-(3,4-dimethoxyphenyl)-n-propanol (3.84 mmol) was added to a stirred solution of dicyclohexylcarbodiimide (1.19 g, 5.77 mmol), 4-(dimethylamino)pyridine (0.038 g, 0.31 mmol) and 3,5-dimethoxybenzoic acid (5.77 mmol) in dry CH 2 CI 2 (8.5 ml) (Kato 1985). The mixture was stiπed at room temperature for 12 h, and then diluted with hexane (2 ml). The mixture was filtered and the solid material was washed with CH 2 C1 . The combined filtrate and washings were concentrated in vacuo and then subjected to silica gel chromatography. 3-(3,4-dimethoxyphenyl)-n-propyl 3,5- dimethoxybenzoate was analysed by NMR and mass spectroscopy. Compound 30 - methyl 4-hydroxy-3,5-dimethoxybenzoate 4-hydroxy-3,5-dimethoxybenzoic acid (10 mmol) was refluxed with excess metha- nol in the presence of sulphuric acid, and then partitioned between water and ethyl acetate. MPLC of the ethyl acetate layer gave methyl 4-hydroxy-3,5-dimethoxy- benzoate in 59% yield. 1H NMR: 7.21 (s, 2H), 6.20 (br.s, IH), 3.80 (s, 6H), 3.80 (s, 3H); I3 C NMR: 166.9 (C=0), 146.5 (Ar-C), 139.1 (Ar-C), 120.6 (Ar-C), 106.4 (Ar-C), 56.1 (OMe), 51.8 (OMe). Compound 34 - methyl 3,4-methylenedioxybenzoate 3,4-methylenedioxybenzoic acid (2.25 g, 13.6 mmol) was refluxed with excess methanol in the presence of sulphuric acid for 12 hours. The reaction mixture was partitioned between water and ethyl acetate. MPLC of the ethyl acetate layer gave methyl 3,4-methylenedioxybenzoate in 52.6% yield. 1H NMR: 6.76 (d, J = 1.83 Hz, IH), 6.73 (d, J = 7.94 Hz, IH), 6.68 (dd, J=7.93, 1.52 Hz, IH), 5.89 (s, 2H), 3.66 (s, 3H). Compound 83 - N-ethyl 3,5-dimethoxybenzamide 3,5-dimethoxybenzoyl chloride was stiπed with excess ethylamine solution (70 % in water) for 3 days, and then partitioned between water and ethyl acetate. MPLC of the ethyl acetate layer gave ethyl 3,5-dimethoxybenzamide. Compound 84 - ethylthionyl 3,5-dimethoxybenzoate Ethanethiol (3.84 mmol) was added to a stiπed solution of dicyclohexyl- carbodiimide (1.19 g, 5.77 mmol), 4-(dimethylamino)pyridine (0.038 g, 0.31 mmol) and 3,5-dimethoxybenzoic acid (5.77 mmol) in dry CH 2 CI 2 (8.5 ml) (Kato 1985). The mixture was stiπed at room temperature for 12 h, and then diluted with hexane (2 ml). The mixture was filtered and the solid material was washed with CH 2 C1 2 . The combined filtrate and washings were concentrated in vacuo and then subjected to silica gel chroma- tography. Ethylthionyl 3,5-dimethoxybenzoate was analysed by NMR and mass spectroscopy. Compound 85 - 2.2.2-trifluoroethyl 3,5-dimethoxybenzoate 2,2,2-trifluoroethanol (3.84 mmol) was added to a stiπed solution of dicyclohexyl- carbodiimide (1.19 g, 5.77 mmol), 4-(dimethylamino)pyridine (0.038 g, 0.31 mmol) and 3,5-dimethoxybenzoic acid (5.77 mmol) in dry CH 2 CI 2 (8.5 ml) (Kato 1985). The mixture was stiπed at room temperature for 12 h, and then diluted with hexane (2 ml). The mixture was filtered and the solid material was washed with CH 2 C1 2 . The combined filtrate and washings were concentrated in vacuo and then subjected to silica gel chromatography. 2,2,2-trifluoroethyl 3,5-dimethoxybenzoate was analysed by NMR and mass spectroscopy. Compound 86 - (E)-3-n-hexenyl 3,5-dimethoxybenzoate (E)-3-n-hexenol (3.84 mmol) was added to a stirred solution of dicyclohexylcar- bodiimide (1.19 g, 5.77 mmol), 4-(dimethylamino)pyridine (0.038 g, 0.31 mmol) and 3,5-dimethoxybenzoic acid (5.77 mmol) in dry CH 2 CI 2 (8.5 ml) (Kato 1985). The mixture was stiπed at room temperature for 12 h, and then diluted with hexane (2 ml). The mixture was filtered and the solid material was washed with CH 2 C1 2 . The combined filtrate and washings were concentrated in vacuo and then subjected to silica gel chromatography. (E)-3-n-hexenyl 3,5-dimethoxybenzoate was analysed by NMR and mass spectroscopy. Compound 87 - trideuteriomethyl 3,5-dimethoxybenzoate Trideuteriomethanol (3.84 mmol) was added to a stiπed solution of dicyclohexyl- carbodiimide (1.19 g, 5.77 mmol), 4-(dimethylamino)pyridine (0.038 g, 0.31 mmol) and 3,5-dimethoxybenzoic acid (5.77 mmol) in dry CH 2 CI 2 (8.5 ml) (Kato 1985). The mixture was stiπed at room temperature for 12 h, and then diluted with hexane (2 ml). The mixture was filtered and the solid material was washed with CH 2 C1 . The combined filtrate and washings were concentrated in vacuo and then subjected to silica gel chromatography. Trideuteriomethyl 3,5-dimethoxybenzoate was ana- lysed by NMR and mass spectroscopy. Compound 88 - 2-methoxy-4-(2-propenyl)phenyl 3,5-dimethoxybenzoate 2-methoxy-4-(2-propenyl)phenol (3.84 mmol) was added to a stiπed solution of di- cyclohexylcarbodiimide (1.19 g, 5.77 mmol), 4-(dimethylamino)pyridine (0.038 g, 0.31 mmol) and 3,5-dimethoxybenzoic acid (5.77 mmol) in dry CH 2 CI 2 (8.5 ml) (Kato 1985). The mixture was stiπed at room temperature for 12 h, and then diluted with hexane (2 ml). The mixture was filtered and the solid material was washed with CH 2 C1 2 . The combined filtrate and washings were concentrated in vacuo and then subjected to silica gel chromatography. 2-methoxy-4-(2-propenyl)phenyl 3,5- dimethoxybenzoate was analysed by NMR and mass spectroscopy. Example 2 - Test of gnawing-inhibiting effect of substances applied on pine bark. For each test, 40 pine weevils (20 females + 20 males) were used placed in separate Petri dishes provided with a piece of a pine twig enveloped in aluminium foil. In the foil, two holes with a diameter of 5 mm were punched, whereby the underlying bark was exposed. One of the two surfaces exposed was treated with the substance that was tested and the other surface was left untreated. After 6 and 24 hours, respec- tively, it was recorded whether the pine weevil had started to eat on the treated and untreated surface, respectively. In Table 2 the gnawing-inhibiting effect is shown by means of the following index: (C-T)xlOO (C+T) , wherein C is the number of control surfaces with gnawing and T is the number of treated surfaces with gnawing. It was tested if there was a statistic sig- nificant difference between treatment and control with a chi -test of a 2x2 table (not continuity coπected): *=p<0.05, **=p<0.01, ***=p<0.001. The most active substances were compound no 22, 15, and 14, above all shown by the value after 24 hours. Table 2. Test of gnawing-inhibiting effect of substances applied on pine bark. As seen from the table, compounds No. 22 and 87 were most active. Example 3 - Field test with 75 saplings The substance with the strongest repellent effect in the laboratory test (no. 22, M- 3,5-DMB) has also been tested in field experiments by applying it in a matrix brushed on the saplings before plating. The substance (40 g) was mixed with Bol- torn H40 ® (a dendritic polymer (a polyol) from Perstorp AB, SE-284 80, Sweden, CAS no. 150 504-00-0; 20 g) and isopropanol (80 ml). This mixture was used for 75 saplings. This treatment significantly reduced the extent of gnawing on saplings, and the effect was so strong that it definitely should be useful for practical protec- 27 tion from pine weevil damage (Table 2). The effect seems considerably stronger compared to earlier field testing gnawing-inhibiting agents against the pine weevil (Eidmann 1984, Schlyter 1998). Table 2. Result of a field test with 75 saplings that have been subjected to one of the following three treatments: A = totally untreated saplings, B = saplings only treated with the matrix, C = saplings treated with M-3,5-DMB (substance no. 22) in the matrix. A B C Number of attacked saplings 34 28 16 Gnawed surface (mm ) per sapling ± SE 175 ± 36 117 ± 27 6 ± 2 Gnawed surface (mm ) per attacked sapling ± SE 387 ± 62 315 ± 54 30 ± 7 References Baeckstrόm, P., Stridh, K., Li, L. and Norin, T. Acta Chem. Scand. B 41 (1987) 442. Eidmann, H. H. & Nordenhem, H. 1984. Lovande fδrsδk med avskrackande medel mot snytbaggar och barkboπar. Skogen 1984(9):30-31. Kato, M. & Mori, K.: Agric. Biol. Chem. 49(10), 3073 (1985). Langstrόm, B. 1998. Varfόr ar snytbaggen fortfarande ett problem? Kungliga Skogs- och Lantbruksakademiens Tidskrift 137(15):23-33. Nordlander, G. 1998. Vad kan vi gora at snytbaggeproblemet? Kungliga Skogs- och Lantbruksakademiens Tidskrift 137( 15):35-41. Schlyter, F. & Lofqvist, J. 1998. Kan insekticider mot snytbaggar ersattas med naturliga eller syntetiska "antifeedants"? Kungliga Skogs- och Lantbruksakademiens Tidskrift 137(15):51-58. Weslien, J. 1998. Vad kostar snytbaggeskadorna? Kungliga Skogs- och Lantbruksakademiens Tidskrift 137(15): 19-22. Viktorov-Nabokov, O.V.; Kovalenko, L. G.; Malevannaya, Z. A.; Skrynik, E. M.; Sholudchenko, L. I. 1980. Effect of substituents in a series of benzoic acid esters and amides on repellence with respect to blood-sucking mosquitoes. Fiziol. Akt. Veshchestva, 12:96-98. Orlander, G. & Nordlander, G. 1998. Skarmar, markberedning och andra skogsskot- selatgarder - kan de minska snytbaggeskadorna? Kungliga Skogs- och Lantbruksakademiens Tidskrift 137(15):59-69. Orlander, G. & Petersson, M. 1998. Mekaniska skydd. Kungliga Skogs- och Lantbruksakademiens Tidskrift 137(15):43-50.

Claims: 29 Claims 1. Use of at least one compound for conifer sapling protection, characterised in that the compounds are selected from the following compounds with Formula I: Formula I wherein Ri, R 2 , R 3 , j, and R 5 each independently stand for - hydrogen; - hydroxy; - a Cι-Cι -alkyl group, optionally substituted with one or more halogen, hydroxy or C Cι 2 -alkoxy groups; - a Cι-Cι -alkoxy group, optionally substituted with one or more halogen, hydroxy or C Cι -alkoxy groups; - a nitto group; or - halogen; R ' stands for - a C Cι 2 -alkyl group, optionally substituted with one or more halogen, hydroxy or C C 12 -alkoxy groups; - a hydroxy substituted C]-Cι 2 -hydrocarbon group; - a methylcarboxylic group; or 30 - C(0)XR " , wherein - X stands for a heteroatom; and - R " stands for - hydrogen; - a Cι-Cι 2 -alkyl group, optionally substituted with one or more deuterium groups, halogen, hydroxy, aryl, optionally substituted with one or more Ci-Ci 2 -alkyl groups, C C 12 -alkoxy groups, or d-Ci 2 -alkoxy groups; or - an aryl group, optionally substituted with one or more C Cι 2 -alkyl groups, C r Cι 2 -alkoxy groups; as well as esters and salts thereof. 2. Use of a composition for conifer sapling protection, characterised in that it comprises at least one of the following compounds with Formula I: Formula I wherein Ri, R 2 , R 3 , R 4 , and R 5 each independently stand for - hydrogen; - hydroxy; - a Cι-C 12 -alkyl group, optionally substituted with one or more halogen, hydroxy or C Cι 2 -alkoxy groups; - a C Cι -alkoxy group, optionally substituted with one or more halogen, hydroxy or Cj-Cι 2 -alkoxy groups; - a nitro group; or - halogen; R ' stands for - a C]-C I2 -alkyl group, optionally substituted with one or more halogen, hydroxy or Cι-C[ 2 -alkoxy groups; - a hydroxy substituted Cι-Cι 2 -hydrocarbon group; - a methylcarboxylic group; or - C(0)XR", wherein - X stands for a heteroatom; and - R " stands for - hydrogen; - a Cι-Cι 2 -alkyl group, optionally substituted with one or more deuterium groups, halogen, hydroxy, aryl, optionally substituted with one or more Cι-C 1 -alkyl groups, C Cι 2 -alkoxy groups, or Cι-C 1 -alkoxy groups; or - an aryl group, optionally substituted with one or more C Cι 2 -alkyl groups, C]-C ]2 -alkoxy groups; as well as esters and salts thereof, pure or in a solvent, with or without a suitable carrier. 3. Use according to Claim 1 or 2, characterised in that the compounds are selected from the following compounds with Formula I: Formula I wherein Ri, R 2 , R 3 , R,, and R 5 each independently stand for - hydrogen; - hydroxy; - a Cι-C 8 -alkyl group, optionally substituted with one or more halogen, hydroxy or Cj-Cg-alkoxy groups; - a Cι-C 8 -alkoxy group, optionally substituted with one or more halogen, hydroxy or Cι-C 8 -alkoxy groups; - a nitro group; or - halogen; R' stands for - Cι-C 8 -alkyl group, optionally substituted with one or more halogen, hydroxy or C]-C 8 -alkoxy groups; - a hydroxy substituted Cι-C 6 -hydrocarbon group; - a methylcarboxylic acid or a methylcarboxylic Cι-C 6 -ester group; or - C(0)XR " , wherein - X stands for a heteroatom; and - R" stands for - hydrogen; - a Cι-Cι -alkyl group, optionally substituted with one or more deuterium groups, halogen, hydroxy, aryl, optionally substituted with one or more C C -alkyl groups, Cι-C 8 -alkoxy groups, or Ci-C 8 -alkoxy groups; or - an aryl group, optionally substituted with one or more Cι-C 8 -alkyl groups, C C 8 -alkoxy groups; as well as esters and salts thereof. 4. Use according to Claim 1-3, characterised in that the compounds are selected from the following compounds with Formula I: Formula I wherein Ri, R , R 3 , R 4 , and R 5 each independently stand for - hydrogen; - hydroxy; - a Cι-C 6 -alkyl group, optionally substituted with one or more halogen, hydroxy or C]-C 6 -alkoxy groups; - a Cι-C 8 -alkoxy group, optionally substituted with one or more halogen, hydroxy or Cι-C 6 -alkoxy groups; - a nitro group; or - halogen; R ' stands for - Cι-C 6 -alkyl group, optionally substituted with one or more halogen, hydroxy or Cj-C ό -alkoxy groups; - a hydroxy substituted C]-C 3 -hydrocarbon group; - a methylcarboxylic acid or a methylcarboxylic C C 6 -ester group; or - C(0)XR", wherein - X stands for a heteroatom; and - R " stands for - hydrogen; - a C C 1 -alkyl group, optionally substituted with one or more deuterium groups, halogen, hydroxy, aryl, optionally substituted with one or more C C 6 -alkyl groups, Cj-C 6 -alkoxy groups, or Cι-C 6 -alkoxy groups; or - an aryl group, optionally substituted with one or more Cι-C 6 -alkyl groups, Ci-C ό -alkoxy groups; as well as esters and salts thereof. 5. Use according to Claim 1-4, characterised in that the compounds are selected from the following compounds with Formula I: Formula I wherein Ri, R 2 , R 3 , R 4 , and R 5 each independently stand for - hydrogen; - hydroxy; - a Cι-C 6 -alkyl group; - a C C 8 -alkoxy group; - a nitro group; or - halogen; R' stands for - Cj-C 6 -alkyl group; - a hydroxy substituted Cι-C 3 -hydiOcarbon group; - a methylcarboxylic acid group; or - C(0)XR " , wherein - X stands for a heteroatom; and - R" stands for - hydrogen; - a CpCι -alkyl group, optionally substituted with one or more deuterium groups, halogen, hydroxy, aryl, optionally substituted with one or more Cj-Ce-alkyl groups, Cι-C 6 -alkoxy groups, or Cj-C 6 -alkoxy groups; or - an aryl group, optionally substituted with one or more Cι-C 6 -alkyl groups, C C 6 -alkoxy groups; as well as esters and salts thereof. 6. Use according to Claim 1-5, characterised in that the compounds are selected from the group consisting of: homovanillic acid 3 -(4-hydroxy-3 -methoxyphenyl)- 1 -propanol 3-(3,4-dimethoxyphenyl)-l-propanol 3,5-dimethoxybenzyl alcohol methyl 2,4-dihydroxybenzoate methyl 3,4-dihydroxybenzoate methyl 3,5-dihydroxybenzoate methyl 2-hydroxy-4-methoxybenzoate methyl 3,4-dimethoxybenzoate n-dodecyl 3,4-dimethoxybenzoate 3-(3,4-dimethoxyphenyl)-n-propyl 3,5-dimethoxybenzoate 2-hydroxy-3-methoxybenzoic acid 2-hydroxy-5-methoxybenzoic acid 3-hydroxy-4-methoxybenzoic acid 3,4-dimethoxybenzoic acid methyl 3,5-dimethoxybenzoate methyl 4-hydroxy-3,5-dimethoxybenzoate methyl 3,4,5-trimethoxybenzoate methyl 3,4,5-trihydroxybenzoate methyl 4-hydroxybenzoate methyl 3,4-methylenedioxybenzoate 3,5-dimethoxy-4-hydroxybenzoic acid piperonylic acid methyl 3-chloro-4-methoxybenzoate methyl 2-hydroxy-3 -methoxybenzoate methyl 4-hydroxy-3 -methoxybenzoate methyl 2-hydroxy-5-methoxybenzoate methyl 3-hydroxy-4-methoxybenzoate methyl 2,3-dimethoxybenzoate isoeugenol eugenol methylisoeugenol methyleugenol 3,5-dimethoxyphenylacetic acid isopropyl 4-hydroxybenzoate methyl 4-n-octyloxybenzoate methyl 2-hydroxybenzoate methyl 2,4-dihydroxy-3 ,6-dimethylbenzoate methyl 3,5-dibromobenzoate methyl 3 , 5 -dinitrobenzoate 3,5-dimethoxybenzoic acid N-ethyl 3,5-dimethoxybenzamide ethylthionyl 3 , 5 -dimethoxybenzoate 2,2,2-trifluoroethyl 3,5-dimethoxybenzoate (E)-3-n-hexenyl 3,5-dimethoxybenzoate trideuteriomethyl 3,5-dimethoxybenzoate 2-methoxy-4-(2-propenyl)phenyl 3,5-dimethoxybenzoate. 7. Use according to Claim 1-6, characterised in that the conifer sapling protection relates to protection against insects. 8. Use according to Claim 7, characterised in that the insect species belong to the beetle (Coleoptera) family Curculionidae (including subfamilies Curculioninae and Scolytinae), particularly species of the genera Hylobius, Pachylobius and Hylastes, specifically the species Hylobius abietis, Hylobius pinastri, Hylobius pales, Hylobius congener, Pachylobius picivorus, Hylastes brunneus and Hy- lastes cunicularius . 9. Use according to Claim 2-8, characterised in that the solvent is selected from the group consisting of Ci-C ό -alkohols and Cι-C 6 -alkyl esters of Ci-C ό -alkanoic acids, preferably methyl acetate, methanol, and isopropanol. 10. Use according to Claim 2-9, characterised in that the suitable caπier is selected from the group consisting of wood, cellulose, wood-flour, straw, cork, cane, lig- nin, lignocellulose, rubber, gum, leather or skin, milled carbon, fats or waxes of animal, vegetable, or synthetic origin, natural resins of animal or vegetable ori- gin, plastic, organic polymers such as polyvinyl acetate, polyaciylates, polyvinyl chloride, chlorinated polyethylene, polyols such as polyethylene glycol, synthetic or natural latexes, silicone polymers or resins, silicates, pumice, silica, or any mixture thereof.

Inventors: BORG-KARLSON ANNA-KARIN, NORDENHEM HENRIK, NORDLANDER GOERAN, UNELIUS RIKARD, BORG-KARLSON, ANNA-KARIN, NORDENHEM, HENRIK, NORDLANDER, GOERAN, UNELIUS, RIKARD
Applicants: BORG KARLSON ANNA KARIN, NORDENHEM HENRIK, NORDLANDER GOERAN, UNELIUS RIKARD, BORG-KARLSON, ANNA-KARIN, NORDENHEM, HENRIK, NORDLANDER, GOERAN, UNELIUS, RIKARD
Application year: 2000
Main classification: A01N37
IPC codes: A01N31, A01N37, A01N43