Synthesis of Chloro Alkoxy and Alkoxy Derivatives of Methyl Oleate

Abstract

Vegetable oil based lubricants typically have improved lubricity and biodegradability over their mineral oil based counterparts. However, vegetable oil lubricants often fail to meet the performance standards of mineral based oils with respect to cold temperature and resistance to oxidation. Olefins are an oxidatively weak point for vegetable based compounds. Removal of the olefin in a vegetable based lubricant through functionalization may increase resistance to oxidation. If the added functionality also causes branching of the alkyl chain, cold temperature properties may be improved. Any chemical modifications considered must be scalable and cost-effective to be useful in a commercial application. In this study, methyl oleate was functionalized into a chloro alkoxy derivative. Sodium hypochlorite (household bleach) and calcium hypochlorite were both used to generate hypochlorous acid in situ. Hypochlorous acid and a series of alcohols (methanol, ethanol, and butanol) were reacted with methyl oleate to make chloro alkoxy compounds in 29.8-77.9 % yields. In an effort to make a branched saturated ether we removed the chlorine moiety of the chloro alkoxy compounds. Dehalogenation was achieved under basic conditions over a Pd/C catalyst in 2-propanol. Reaction times increased substantially as the size of the adjacent alkoxy group increased. The reaction rate could be improved by heating the reactions above 100°C in a pressure reactor. Increased reaction temperature also resulted in an increase in ketone side products from the competing elimination reactions. Saturated ether yields were 4.1-43.2 %.Names are necessary to report factually on available data; however, the USDA neither guarantees nor warrants the standard of the product, and the use of the name by USDA implies no approval of the product to the exclusion of others that may also be suitable.Electronic supplementary material The online version of this article (

Transformation of Unsaturated Fatty Acids/Esters to Corresponding Keto Fatty Acids/Esters by Aerobic Oxidation with Pd(II)/Lewis Acid Catalyst

“…Because of the renewable availability and biodegradability, not only utilization as biofuel, these plant oils, for example, vegetable oils, have also been employed in the preparation of drying oils for paints and coatings after transformation to conjugated derivatives − and employed as the monomer of biopolymers after epoxidation. − Because of the unsaturated CC bond in plant oils, utilization of unmodified vegetable oils as lubricants generally faces the aging challenge. Accordingly, elimination of the CC double bond through ketonization or formation of chloro alkyoxy derivatives was reported to improve the quality of vegetable oil based lubricants. , …”

“…Accordingly, elimination of the CC double bond through ketonization or formation of chloro alkyoxy derivatives was reported to improve the quality of vegetable oil based lubricants. 11,12 While transesterification, isomerization, and epoxidation of versatile vegetable oils have been widely investigated and partly applied in industry, the studies on ketonization of unsaturated fatty acids and their derivatives are very limited until now. In literature, Sels and co-workers 13 reported a nitrous oxide based oxidation of unsaturated fatty acid esters and triacylglycerol mixtures to the keto fatty esters in the absence of solvent and metal ion catalyst; Knothe 14 also developed the synthesis of long-chain 1,2-dioxo methyl esters of monounsaturated fatty acid with potassium permanganate as oxidant.…”