Patented Oct. 15, 1946 2,409,329 UNITED STATES PATENT OFFIC 2,409,329 n ' ORGANIO ‘ THIOCYANO COMPOUNDS Paul H. Williams,‘ Berkeley, Calif., assignor to Shell Development Company, San Francisco, Calif., a corporation of Delaware No Drawing. ‘Application February 28, 1944, ' ‘ Serial N 0. 524,309 9 Claims. . (Cl. 260-454) . n 1 l 2 n This invention relates to organic ‘thiocyano critical importance, those compounds are pre ferred wherein the alkyl groups contain less than ?ve carbon atoms, especially those wherein all of the alkyl groups are methyl groups. Especially desirable are those compounds in which‘there are compounds, and more particularly , pertains to compounds of the general formula 0 II . I R—-‘O—C—X ‘ two methyl groups on the cyclohexyl radical, one wherein is an yalkyl-substit'uted cyclohexyl radical containing at least two alkyl groups, ‘and substituted in the 3 position and the other in the 5 position, and those wherethere are three sub X is a thiocyano-substituted hydrocarbon radical. stituent methyl groups, especially those where The. organic thiocyano compounds of ‘the in 10 there are two methyl groups in the 3 position vention have many importantluses. 'Theymay, and one in “the 5 position. Thus 3,5-dimethyl for example, be used as wetting agents,.‘as plas ticizers, as addition. agents for rubber, and .as in cyclohexyl thiocyanoacetate, CH3 \oH-om termediates in the synthesis “of, other valuable organic compounds. They are particularly user 15 on; ful, as insecticides, fungicides and parasiticides since, in addition to possessing‘ unusually high ~ ‘ ‘ " ~ ' ' 0 \OH-—O—g-—CHa—SON ‘ \CH—CHz insecticidal activity, they havev an, inoifensive odor, are light-stable, are‘compatible with or sol .C‘ a uble in light para?inic mineral oils such as kero 20 and 3,3,5-trimethylcyclohexyl thiocyanoacetate, sene, and are not damaging in any way to fabrics, ‘ CH3 wall paper, painted walls, etc. This use of‘ the Oil-CH: compounds of the invention as insecticides, fungi cides and parasiticides is described and ‘claimed in the .copending application,v ‘Serial Number‘ 25 482,032, ?led April 6, 1943, of ‘which this applica tionis‘acontinuation-impart. “ p. 1 “ s CH: ' on-o-c'L-ora-sosr \o~_om ' on; on,‘ have been found to be especially desirable ‘com ‘ Theorganic thiocyano compounds or the in vention have the general formula ’ pounds of this type when considered from‘ the’ 30 standpoint of their general utility, their e?ective‘e mass as insecticides, and their ease and economy r - ‘ _ ‘ Ib-O-PJ-X of preparation. wherein R is an alkyl-substituted cyclohexyl , . , 7 Although the radical represented by X in the hereinabove de?ned general formula radical which is, substituted ‘with at‘ least two alkyl groups, and X is a ‘thiocyano-substituted 35 hydrocarbon radical. ‘ ‘ ' ' Suitable alkyl group substituents on the cyclo hexyl radical are, for example, the methyl, ethyl, may be any thiocyano-substitutecl hydrocarbon propyl, butyl, amyl, hexyl, heptyl, o‘ctyl, nonyl, etc., radicals and theirhom‘ologues; aswell as certain unsaturated radicals such as the allyl, radical, it is preferably a mono-, die, or poly: .40 thiocyano substituted aliphatic radical derived methallyl, crotyl, etc.,.radica1s.v The said groups may be substituted in any desired position on the from the saturated or unsaturated aliphatic acid of corresponding structure. The resulting pre ferred compounds are, therefore, the alkyl-sub cyclohexyl radical, although the third and ?fth ‘ stituted cyclohexyl esters of the mono” di-, or carbon atoms relative to the carbon atom bearingv :45 poly-thiocyano substituted saturated or unsatu the bond to the oxygen atom represent preferred rated aliphatic acids. The aliphatic acid residue positions. In‘ these preferred compounds the car—... may be of any desired-molecular weight, depend bon atomsof the cyclohexyl‘nucleus maybe ing upon the use to which the ester. is to be put. linked to the alkyl groups in any possible manner The alkylcyclohexyl esters of the lower thiocyano of ‘distribution, ‘i. e., one alkyl group on each of 50 aliphatic acids having from 2 to 6 carbon atoms the carbon atoms, in the 3 and 5 positions, one may, for example, be particularly effective foruse ’ alkyl group on one of the indicatedcarbon atoms as insecticidal toxicants while the cyclohexyl and two on the other,“ or- two alkyl groups on esters of the higher acids, i. e. those having up either or both of the indicated carbon atoms. to about 20 carbon atoms, may be more suitable Although the" sizeof the ‘r alkyl group is 'notof 55 for use as wetting agents. ‘ 2,409,329 3 Representative acids, which may be used in forming the desired thiocyano esters include the C2 to C20 straight chain and branched chain satu rated and unsaturated aliphatic acids such as acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, capric acid, undecylic acid, un decylenic acid, lauric acid, myristic acid, palmitic acid, oleic acid, stearic acid, arachidic acid, and C1 4 substituted aliphatic carboxylic acids, including monochloroacetic acid, dichloroacetic acid, tri chloroacetic acid, alpha-chloropropionic acid, beta-chloropropionic acid, the dichloropropionic acids, the dichlorobutyric acids, the chloroiso valeric acids, the chlorolauric acids, the chloro myristic acids, the chlorostearic acids, the chlo roleic acids, the chlororicinoleic acids, the chloro malonic acids and the corresponding bromo- or their homolo-gues and analogues together with suitably substituted compounds thereof, such as 10 iodo-substituted acids. Mixtures may be utilized if desired, as may the anhydrides of the halogen hydroxyacetic acid, lactic acid, dehydro-xy-n substituted carboxylic acids, or the acyl halides butyric acid, d-hydroxyisovaleric acid, ricinoleic of these halogen substituted carboxylic acids. acid, etc. The compounds of the invention may be pre pared in a variety of ways. They may be pre Suitable metal thiocyanates for use in the syn 15 thesis include those which are of a su?iciently re active nature to undergo reaction with a halogen pared, for example, by reacting metal thiocya substituted aliphatic acid. It is also desirable nates with the sulfated esters of the appropriate that the metal thiocyanates be relatively soluble alcohols. However, a preferred method of prep in the reaction medium. In general, ammonium aration generally comprises reacting an alkyl sub stituted cyclohexanol, e. g. 3,3,5-trimethyl cyclo 20 thiocyanate, the thiocyanates of the alkali metals, and the thiocyanates of the alkaline earth metals hexanol (dihydroisophorol) in the presence of represent suitable reagents for use in effecting an esteri?cation catalyst, if desired, with a suit“ the conversion of the halogen substituted esters able halo-gen substituted acylating agent, and re to the thiocyano substituted esters. Ammonium acting the ester so produced with a suitable metal thiocyanate to obtain the desired thiocyano ester. 25 thiocyanate, sodium thiocyanate, ‘potassium thio cyanate, are preferred members of this group. These reactions may be represented by the follow As examples of preferred methods of forming ing equations wherein R=an alkyl substituted the desired compounds of the present invention cyclohexyl radical containing at least two alkyl the following may be given: groups: 0 0 ¢ % ROH + memo-0H —-> ClCHzC-OR + H10 0 0 § \ no-oorncl + NHASCN A RO—CCHZ—SCN + NHlOl As indicated, it may be desirable when effecting the esteri?cation of an alkyl substituted cyclo hexanol with an acylating agent, e. g. a halogen substituted aliphatic carboxylic acid, to make use of an esteri?cation catalyst to accelerate there action. Almost any of the esteri?cation catalysts known to the art may be used for this purpose. Suitable catalysts include, for example, the min eral acids such as sulfuric acid or phosphoric acid. Para-toluene sulfonic acid represents a preferred catalyst, since it exerts the desired cata lytic action without producing any substantial charring of the constituents of the reaction mix 30 In a, 250 ml. flask equipped with a, re?ux con denser was placed 142 g. (1.0 mol) of 3,3,5-tri methylcyclohexanol (dihydroisophorol) and while maintaining the temperature of the reaction mix ture at 80° C., 124 g. (1.1 mols) of chloroacetyl chloride was added dropwise. After reaction had ceased, the mixture was cooled and washed with water and 5% aqueous sodium carbonate and then distilled. 3,3,5-trimethylcyclohexyl chloro acetate, having a. boiling point of 109° C. to 110° C. at 5 mm. pressure and by analysis a 16.25% chlorine content (16.25% theoretical chlorine content) was obtained. Into a one liter ?ask was placed 164 g. (0.75 mol) of the resultant 3,3,5-trimethylcyclohexyl chloroacetate, '76 g. (1.0 mol) of ammonium thiocyanate, and 400 cc. of ethanol (95%). The mixture was re?uxed for about one hour and then the ammonium chloride formed was ?ltered off. The ethanol was re ture. The catalysts are active in small amounts, moved by distillation and the remaining material an amount of catalyst which is equal to but about 50 was distilled through a Claisen ?ask at reduced 1% by weight of the alcohol used being a suificient pressure to obtain 3,3,5-trimethylcyclohexyl thio amount in most cases. cyanoacetate having a boiling point of 134° C. to Either step or stage of the above-described pre 138° C. at ca. 3 mm. pressure, which material ferred method for preparing the presently dis gave on analysis a sulfur content of 13.27% closed thiocyano esters may be carried out in the 55 (13.1% sulfur-—theoretical for C12H19O2SN). presence of an inert solvent, such as methanol, In another .case the 3,3,5-trimethylcyclohex ethanol, isopropanol, butanol, isobutanol, ace anol was ?rst separated into its cis and trans tone, ethyl acetate, benzene, toluene, xylene, hex forms. One isomer had a boiling point of anes, octanes, isopropyl ether, hydrocarbon frac 108.1° C. to 108.4" C. at 50 mm. pressure, and the tions, such as gasoline, etc. It is usually preferred 60 other isomer had a boiling point of 117.2° C. to to carry out the second step, i. e. the conversion 118.0° C. at 50 mm. pressure. Since the evidence of the chloro ester to the thiocyano ester, in an is not conclusive as to which is the cis and which alcoholic medium. Each step may be carried out is the trans form, these forms are herein referred at any temperature within the range of between to as the “low boiling” and the “high boiling” about 0° C. and about 250° C., and preferably in 65 types. The thiocyanoacetates of both of these the range of between about 50° C. and about isomers were prepared as in the above example. The isomer of 3,3,5-trimethylcyclohexyl thiocy 150° C. It may be desirable to carry out the re anoacetate prepared from the “low boiling” prod actions of either step in the absence of oxygen, uct had a boiling point of 134° C. to 142° C. at 3 as, for example, in an atmosphere of carbon di oxide. The products of each stage are preferably 70 mm. pressure and a sulfur content by analysis of vacuum distilled, although if only a crude prod 13.6% (13.27% su1fur—theoretical) , and the 3,3,5 trimethylcyclohexyl thiocyanoacetate isomer pre uct is desired, no distillation is needed. pared from the “high boiling” form had a boiling Suitable halogen substituted acylating agents point of 130° C. to 131° C. at 3 mm. pressure and include the halogen substituted aliphatic car boxylic acids, e. g. the chloro-, bromo- or iodo 75 a sulfur content by analysis of 13.6%. 2,409,829" In a ‘like manner 3,3,5‘-trimethylcyclohexyl thiocyanoacetate was prepared from a mixture of the cis and trans forms of 3,3,atrimethylcyclo hexanol by reacting the latter with chloroacetic clohexanol and chloro acetic acid; 3,3-dimethyl-" 5-ethyl-5 - propyl - cyclohexyl thiocyanoacetate from 3,3 - dimethyl-5-ethyl-5-propyl-cyclohex acid in the presence of toluene as an entraining agent for water and then reacting the resulting product with ammonium thiocyanate. This prod anol and chloro acetic acid; 3-methyl-3-ethyl-5,5 dibutyl-cyclohexyl thiocyanoacetate from 3 uct had a boiling point of 137.5° C. at 3.0 mm. pressure and a sulfur content by analysis of ‘chloro acetic acid; 3-methyl-3-ethyl-5-propyl-5 13.5%. methyl-3-ethyl -' 5,5 - dibutyl-cyclohexanol- and 10 butyl - cyclohexyl In a similar manner 3,3,5-trimethylcyclohexyl thiocyanoacetate from 3 - methyl-3-ethyl-5-propyl - 5 - butyl-cyclohexanol alpha-thiocyano propionate was prepared by and chloro acetic acid; 3,3,5--trimethyl-5-ethyl esterifying 3,3,5-trimethylcyclohexanol ‘with alpha-chloropropionic acid and reacting the cyclohexyl thiocyanoacetate from 3,3,5 - tri methyl-5-ethyl-cyclohexanol and chloro acetic product thus obtained with ammonium thiocy 15 acid; 3,3,5,5-tetramethyl-cyclohexyl thiocyano anate. The 3,3,5-trimethylcyclohexyl alpha-thio acetate from 3,3,5,5~tetramethyl-cyclohexanol cyano propionate product had a boiling point of and chloro acetic acid; 3,3,5,5—tetraethyl-cyclo 149° C. to 151° C. at 4.7 mm. and a sulfur content hexyl thiocyanoacetate from 3,3,5,5-tetraethyl by analysis of 12.6% (12.55%-—theoretical). Similarly, 3,5-dimethyl cyclohexyl thiocyano acetate was prepared by heating 3,5-dimethyl cyclohexanol and chloro acetic acid. 20 I claim as my invention: 1. 3,5-dimethylcyclohexyl thiocyanoacetate. 2. 3,3,5-trimethylcyclohexyl thiocyanoacetate. 3. The 3,3,5-trimethy1cyclohexy1 thiocyanopro pionates. cyclohexanol with a 10% molar excess of chlor acetic acid, a small amount of an esteri?cation catalyst comprising para-toluene sulfonlc acid and a su?icient amount of benzene to serve as an 25 4. An ester of a polyalkyl cyclohexanol and a entraining agent for the water formed during the thiocyano-substituted aliphatic carboxylic acid, course of the reaction. Distillation of the reac~ tion product under subatmospheric pressure re which ester contains no more than three alkyl radicals directly linked to nuclear carbon atoms sulted in the isolation of a good yield of 3,5-di of the cyclohexyl radical, and wherein all of the methylcyclohexyl chloro acetate. The chloro 30 alkyl radicals are directly linked to nuclear car acetate was then converted to the corresponding bon atoms by means of primary carbon atoms, thiocyano acetate by reacting it with a 10% only one of the alkyl radicals being directly molar excess of ammonium thiocyanate in a so linked to the nuclear carbon atom in the 5 posi lution of ethyl alcohol. After removal of the al tion relative to the acid radical, and the other cohol, the thiocyano acetate product was dis 35 alkyl radicals being directly linked to the nuclear tilled. Its boiling point was 114° C. to 119° C./1 carbon atom in the 3 position relative to the acid mm. It contained 13.8% sulfur (calculated for radical. 3,5 - dimethylcyclohexyl thiocyano acetate, 5. An ester of a trialkyl cyclohexanol and a 14.1%). thiocyano-substituted aliphatic carboxylic acid, In a like manner are prepared: 3-methyl,5 ethyl-cyclohexyl thiocyanoacetate from 3 methyl,5 - ethyl - cyclohexanol and chloroacetic acid; 3-butyl,5-methyl-cyclohexyl thiocyanoace tate from 3-butyl,5-methyl-cyclohexanol and chloroacetic acid; 3-methyl,5-isopropyl-cyclo heXyl alpha-thiocyano-oleate from 3-methyl,5 isopropyl-cyclohexanol and alpha~bromo oleic‘ 40 which ester contains only three alkyl radicals directly linked to nuclear carbon atoms of the cyclohexyl radical, two of the alkyl radicals be ing directly linked by means of a primary carbon atom to the nuclear carbon atom in the 3 position relative to the acid radical, and the other alkyl radical being directly linked by means of a pri mary carbon atom to the nuclear carbon atom acid; 3-ethyl,5-propyl-cyclohexyl thiocyanopro in the 5 position relative to theyacid radical. pionate from 3-ethyl,5-propyl~cyclohexanol and alpha-chloropropionic acid; 3»propyl,5-pentyl cyclohexyl thiocyanostearate from 3 -propyl,5-v pentyl-cyclohexanol and alpha-chloro stearic 6. An ester of a dialkyl cyclohexanol and a 50 thiocyano-substituted aliphatic carboxylic acid, which ester contains only two alkyl radicals linked to nuclear carbon atoms of the cyclohexyl’ acid; 3,5 - diethyl - cyclohexyl thiocyanoacetate radical, one of the alkyl radicals being linked di from 3,5-diethyl-cyclohexanol and chloro acetic rectly by means of a primary carbon atom to the acid; 3,5-dimethyl-cyclohexyl dithiocyanoacetate 55 nuclear carbon atom in the 3 position with respect from 3,5-dimethyl-cyclohexanol and dichloro to the acid radical, and the other alkyl radical acetic acid; 3,5-dipropyl-cyclohexyl thiocyano being linked by means of a primary carbon atom acetate from 3,5 - dipropyl - cyclohexanol and to the nuclear carbon atom in the 5 position with bromo acetic acid; 3,5-dibutyl-cyclohexyl thio respect to the acid radical. cyanoisobutyrate from 3,5-dibutyl-cyclohexanol and alpha-chloro isobutyric acid; 3,3-dimethyl, 5-ethyl-cyclohexy1 thiocyanoacetate from 3,3-di 60 methyl-5-ethyl-cyclohexanol and chloro acetic 7. An ester of a polymethyl cyclohexanol and a. thiocyano-substituted aliphatic carboxylic acid, which ester contains no more than three alkyl radicals, all of which are methyl radicals, direct acid; 3,3-diethyl-5~propyl-cyclohexyl thiocyano ly linked to nuclear carbon atoms of the cyclo propionate from 3,3-diethyl-5-propyl-cyclohex~ ‘35 hexyl radical, only one of the methyl radicals be anol and alpha-chloro propionic acid; 3-methyl 5,5-dibutyl-cyclohexyl thiocyanovalerate from 3 methyl - 5,5 - dibutyl-cyclohexanol and alpha ing linked to the nuclear carbon atom in the 5 position relative to the acid radical, and the other methyl radicals being directly linked to the nu clear carbon atom in the 3 position relative to the bromo valeric acid; 3,3,5-tri-ethyl-cyclohexyl thiocyanoacetate from 3,3,5-tri—ethyl-cyclohex 70 acid radical. anol and iodo acetic acid; 3,3,5-tributyl-cyc1o hexyl thiocyanoacetate from 3,3,5-tributyl-cyclo~ hexanol and chloro acetic acid; 3,3,5-tripropyl cyclohexyl beta-thiocyanopropionate from 3,3,5 tripropylécyclohexanol and beta-chloro propionic 75 8. An ester of a trimethyl cyclohexanol and a thiocyano-substituted aliphatic carboxylic acid, which ester contains only three radicals, all of which are methyl radicals, directly linked to nu clear carbon atoms of the cyclohexyl radical, 2,409,329 7 one of the methyl radicals being directly linked to the nuclear carbon atom in the 5 position with respect to the acid radical, and the other two methyl radicals being directly linked to the nu clear carbon atom in the 3 position with respect to the acid radical. . 9. An ester of a dimethyl cyclohexanol and a thiocyano-substituted aliphatic carboxylic acid, which ester contains only two alkyl radicals, both 8 of which are methyl radicals linked to nuclear carbon atoms of the oyclohexyl radical, one of the methyl radicals being directly linked to the nuclear carbon atom in the 3 position relative to the acid radical, and the other methyl radical be ing linked to the nuclear carbon atom in the5 position relative to the acid radical. PAUL H. WILLIAMS.