3,746,748 United States‘ Patent 0 " CC Patented July 17, 1973 1 2 In the foregoing formula R4 represents the geranyl 3,746,748 residue: INSECT CONTROL AGENTS Josef Ratusky and Frantisek Sorm, Prague, Czechoslo (8) CH: CH: vakia, assiguors to Ceskoslovenska Akademie Ved, Prague, Czechoslovakia No Drawing. Filed May 4, 1970, Ser. No. 34,598 Claims priority, application Czechoslovakia, May 14, 1969, 3,415/69 Int. Cl. C07c 69/54 (b) US. Cl. 260-486 R 12 Claims 10 Esters having the above formula can be prepared by effecting a transesteri?cation of lower esters of the corre ABSTRACT OF THE DISCLOSURE sponding acrylic acid by an alcohol of the terpenoid char Juvenile hormone insect control agents based on esters acter in the presence of an alkaline catalyst and a second derived from unsaturated acids of the acrylic acid type. 15 ary amine. Suitable catalysts include sodium hydroxide, Chlorinated esters and epoxides of esters are also dis potassium hydroxide, sodium carbonate, potassium carbo closed and are useful as insect control agents. nate, potassium bicarbonate, and the like. P‘ipen'dine is an example of a secondary amine that can conveniently be used in this reaction, however, other representative second The present invention relates to novel compounds pos 20 ary amines can be used for this reaction as will be clear to sessing juvenile hormone activity for the control of insects, those skilled in the art. compositions for the treatment of insects, the method for The reaction to prepare the ester compounds of For treating insects with the insect control agents, and methods mula I can be represented by the following equation: for making the novel compounds. R!—O=C—OOORl + H4011 —-> R1-o=o~0ooR4+' R5011 The possibility of controlling insects through juvenile 25 hormone level and the control of juvenile hormone was R2 R3 2 R: recognized some years ago in connection with experiments wherein R1, R2 ,R3 and R4 have the same meaning as above performed on hormones extracted from the male Cecropia and R5 is lower alkyl, e.g. 1 to 5 carbon atoms and gen moths. Synthetic compounds possessing juvenile hormone erally most conveniently is methyl. ' activity have been prepared in recent years based on an 30 Identi?cation of esters according to the present inven acid possessing the sesquiterpenoid chain. Synthetic insect tion and determination of the position of the double bond control agents have also been prepared from the sesquiter in respect of the ester grouping can be effected .by nuclear penoid alcohol, farnesol. magnetic resonance measurements. It has been established based on early work in the The following examples illustrate the embodiment of ?eld of insect physiology that juvenile hormones are se 35 the invention relating to compounds of Formula I: creted by insects at certain stages in their lives. It is one of EXAMPLE 1 the secretions of insects which regulate growth and control The alkaline transesteri?cation of methyl methacrylate the metamorphosis from larva to pupa to adult insect. In (10.0 g.; 0.1 mol) with geraniol (15.4 g.; 0.1 mol) is ef the stage where the mature larva undergoes metamorpho fected in the presence of piperidine and cations of an sis into the sexually mature adult, the ?ow of juvenile hor alkali metal, e.g., Na+ (5% by weight of geraniol). The mone ceases. If during this period the larva comes into reaction mixture is stirred at 60° C. for 2 hours, poured contact with the juvenile hormone a lethal derangement into water, and extracted without delay with two 100 of further development takes place which results in failure ml. portions of ether. The etheral extracts are dried and of the larva to mature. The ultimate effect is that the in 45 evaporated. The unreacted methyl methacrylate is re sects are incapable of reproducing. moved by distillation and the residue is chromatographed In one embodiment, the present invention relates to on 1000 g. of neutral alumina (Bro-ckmann activity H) new ester compounds derived from unsaturated acids and in benzene. The required product is isolated (14 g.) from an alcoholic component of the terpenoid character, for the ?rst fractions of the eluate and puri?ed by distilla example, geraniol or 2-methyl-2-hepten-6-ol. tion in vacuum of an oil pump. Yield, 9.0 g. of geranyl In a further embodiment, the present invention relates 50 methacrylate, B.P. 130° C./l0 mm. Hg. For C14H22O2 .to chlorinated esters derived from unsaturated acids of the (222.3) calculated: 75.6% C, 10.0% H; found: 75.43% acrylic acid type. C, 9.82% H. In a still further embodiment, the present invention EXAMPLE 2 relates to epoxides of the esters derived from unsaturated 55 The reaction is effected in analogy to Example 1 ex acids of the acrylic acid type. cept for the use of 2-methyl-2-hepten-6-ol (12.8 g.) in Expressed in terms of structure, the novel ester com stead of geraniol. The reaction mixture is worked up also pounds of the present invention may be represented by in analogy to Example 1. Yield, 7.6 g. of 2-methyl-2 the .following formula: hepten-?-yl methacrylate, B.P. 125—l28° C./10 mm. Hg. For C12H2oO2 calculated: 73.5% C, 10.25% H; found: 73.2% C, 10.35% H. 2 8 Esters of the above Formula I exhibit a medium ju venile hormone activity in the range of 10 to 100 micro— grams of the substance per specimen, particularly beetles. wherein the symbols R1, R2 and R3 designate hydrogen 65 This will be discussed in further detail hereinafter below. atoms or ‘alkyl groups containing from 1 to 5 carbon One of the advantages of the esters according to For atoms. mula I resides in the fact that they can really be converted Where the term “alkyl” is used herein, it refers to to still other novel compounds having new and useful straight or branched chain, saturated aliphatic hydrocar properties. bon groups having a chain length of 1 to 5 carbon atoms Therefore, it is a further embodiment of this invention including methyl, ethyl, propyl, i-propyl, t-butyl and to provide chlorinated esters of compounds of Formula pentyl. I. These chlorinated esters are obtained by the addition 3,746,748 3 4. of hydrogen chloride to one or more double bonds of tion of epoxide rings from one or more of the double the esters of Formula I. Thus, the chlorinated esters are bonds. Thus, the R4 can have the following structures: represented by the formula: wherein R1, R2 and R3 are de?ned as above and where R4 is represented by the following structural formulae: 20 The epoxide derivatives corresponding to the above formulae can be prepared by reacting the parent ester (Formula I) with a small excess, Le. 20%, of organic peracids; for example, perphthalic acid or perbenzoic 25 acid. A suitable solvent such as ether can be used if de wherein X is chlorine (Cl) sired. The product can be puri?ed by washing the eth The preparation of the chloro derivatives according to ereal solution of the reaction mixture with a dilute aque the present invention can be carried out by saturating a ous solution of an alkali hydroxide to remove the acid; solution of the parent ester (Formula I) in a non-polar i.e. the phthalic acid formed during the reaction and the solvent with dry hydrogen chloride. The isolation of the remaining excess perphthalic acid. The epoxide ring is resulting chloro derivative is performed by simple evap considerably sensitive to acid media and therefore acid oration of the solvent in vacuo at a moderate temperature. should be removed. The ?nal puri?cation is performed The following examples illustrate this embodiment of by column chromatography on neutral alumina. the invention: The following examples illustrate this embodiment of EXAMPLE 3 the invention. Geranyl methacrylate hydrochloride EXAMPLE 5 Geranyl methacrylate (2.2 g.; 0.01 mol) obtained ac Geranyl methacrylate epoxide cording to Example 1 above was dissolved in dry ether (20 ml.) and the resulting solution was saturated under 40 A solution of geranyl methacrylate (2.2 g.; 0.01 mol) external ice-cooling and under exclusion of atmospheric in dry ether (5 ml.) was placed into a 100 ml. ?ask pro moisture (calcium chloride guard tube) with dry hydrogen tected against atmospheric moisture (calcium chloride chloride. The reaction mixture was then evaporated at guard-tube) and externally cooled by ice. Ethereal per room temperature under vacuum of a water pump and phthalic acid (13 ml.; 0.01 mol+20% excess) was then added dropwise from a separatory funnel through a thin then an oil pump. As shown by elemental analysis, the 45 residual viscous colorless oil contained 1 chloro atom per layer of magnesium sulfate (the ethereal solution con molecule. As shown by NMR (nuclear magnetic reso tained 0.18 g. of perphthalic acid per 1 ml.). In the course nance) spectra, the hydrogen chloride added to the double of the addition, phthalic acid began to deposit on walls bond more distant from the ester grouping. For of the ?ask. The addition of perphthalic acid took about 15 minutes. The reaction mixture was then allowed to CMHZBOZCI (258.75) calculated: 65.0% C, 8.95% H, 50 13.7% C1; found: 65.3% C, 9.15% H, 13.45% Cl. stand for 30 minutes. The supernatant ethereal solution was decanted from crystals of phthalic acid and washed EXAMPLE 4 with 2% aqueous sodium hydroxide (50‘v ml.). The re 2-methyl-2-hepten-6-yl methacrylate hydrochloride sidual phthalic acid crystals were shaken with a mixture of additional 50 ml.