9(10)-Carboxystearic acid and its mono-and dimethyl esters were esterified and transesterified with 1-butanol, 2-me thoxyethanol, 2-chloroethanol, 2,2-dimethylpentanol, 2-ethylhexanol and 1-octanol. Rate studies for the sulfuric acid-catalyzed esterification of 9(10)-carboxystearic acid to alkyl 9(10)-carboxystearate and alkyl 9(10)-carboalkoxystearate indicate than on an average the terminal carboxyl is approximately 26-27 times more reactive than the branched carboxyl group. Esterification is highly dependent on catalyst concentration. Steric hindrance in 2,2-dimethylpentanol and the electrophilic character of 2-methoxyethanol and 2-chloroethanol markedly retard the rate. In addition to the expected diesters, 2-chloroethanol yields esters containing extra -O-CH2CH 2-groups, The rate of transesterification of the terminal ester group of mono-and lpresented at the AOCS Meeting, Atlantic City, October 1971. 2N. Market. Nutr. Res. Div., ARS, USDA. 91101 I C00--COO--D \ ] t 1 0 4 8 12 lime, M~n. C E 1 t 16 20 24FIG. 1. Gas chromatogram of (A) methyl stearate (reference compound); (B) methyl 9(10)-carbomethoxystearate; (C) methyl 9(10)-carbo(dimethylpentoxy)stearate; (D) dimethylpentyl 9(10)-carbomethoxystearate; (E) dimethylpentyl 9(10)-carbo(dimethylpentoxy)stearate. 302 dimethyt esters of 9(10)-carboxystearic acid is about two times faster than the rate of esterification of the branched carboxyl group. Transesterification of the branched 9( t0)-ester group is extremely slow.
Conditions were determined for selective alkaline transesterification of methyl 9(10)-carbomethoxystearate. With 2,2-dimethylpentanol and 2-ethylhexanol, the corresponding alkyl 9(10)-carbomethoxystearates were obtained in good yield. These two mixed alkyl diesters, along with other alkyl esters of mono-9(10)-, di-and tricarboxystearic acids prepared by conventional methods, were evaluated as lubricants. Several esters compared favorably with dioctyl sebacate used as the control. The esters had high viscosity indices and tow American Society for Testing and Materials slopes. The pour point of purified dimethylpentyt 9(10)-carbomethoxystearate is below -70 C. Several esters have antiwear properties when added to the control oil.
A method is described for the preparation of linseed acid chlorides in excellent yields and functional purity. After linseed acids are reacted with phosphorus trichloride, the mixture is briefly heated in vacuo, cooled, and decanted. The linseed acid chlorides were also distilled in a specially modified molecular still to obtain a nearly colorless product.
and summaryProcedures were developed to extract rhodium from hydroformylated vegetables oils and methyl esters. Among the numerous reagents surveyed, aqueous hydrogen cyanide with triethanolamine (TEA) was found to be most effective. The effects of time, temperature, and concentration of reagents were studied. Over 98% of the solubilized rhodium was removed from crude methyl formylstearate at 100 C for 1 hr with 0.5% hydrogen cyanide, 5% water, and 0.5% TEA. Over 98% of the solubilized rhodium was also extracted from hydroformylated soybean and safflower methyl esters; however, 1% hydrogen cyanide, 10% water, and 0.62% TEA had to be used. Only 90% of the rhodium was removed from hydroformylated soybean oil. The reagents used can be adpated to a continuous extraction procedure.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.