Alcohol-mediated esterification of carboxylic acids with carbonates

Abstract

Esters and a process for making esters from organic acids by means of reacting a carboxylic acid with dialkylcarbonate in an alcohol-containing solvent without any extrinsic acid or base catalyst is described. A benefit of the preparation process is that it can make the separation and extraction of ester products simpler and more facile vis-à-vis conventional isolation techniques.

We claim: 
     
         1 . An ester prepared according to a method comprising reacting a dicarboxylic or tricarboxylic organic acid and a dialkylcarbonate in a reaction mixture with an alcohol-containing solvent absent an extrinsic catalyst. 
     
     
         2 . The ester according to  claim 1 , wherein said organic acid is selected from: formic acid, acetic acid, propionic acid, lactic acid, butyric acid, isobutyric acid, valeric acid, hexanoic acid, heptanoic acid, decanoic acid, lauric acid, myristic acid, and C 14 -C 18  fatty acids, 2,5-furandicarboxylic acid (FDCA), fumaric acid, itaconic acid, malic acid, succinic acid, maleic acid, malonic acid, glutaric acid, glucaric acid, oxalic acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, glutaconic acid, ortho-phthalic acid, isophthalic acid, terephthalic acid, citric acid, isocitric acid, aconitic acid, tricarballylic acid, and trimesic acid. 
     
     
         3 . The ester according to  claim 1 , wherein said dialkylcarbonate is at least one of the following species: dimethylcarbonate (DMC), diethylcarbonate (DEC), dipropylcarbonate (DPC), or dibutylcarbonate (DBC). 
     
     
         4 . The ester according to  claim 1 , wherein said alcohol-containing solvent includes a single alcohol species, a mixture of different alcohols, or a mixture of an alcohol and other non-alcoholic species. 
     
     
         5 . The ester according to  claim 1 , wherein said alcohol in said alcohol-containing solvent is either a saturated, unsaturated, aromatic species, or a mixture thereof. 
     
     
         6 . The ester according to  claim 4 , wherein said non-alcoholic species includes at least one of the following: a carbonate/CO 2 , dimethyl formamide (DMF), dimethyl sulfoxide (DMSO), acetonitrile, tetrahydrofuran (THF), acetone, N-methyl-2-pyrrolidone (NMP), chloroform, and ethyl acetate. 
     
     
         7 . The ester according to  claim 4 , wherein said alcohol serves as a nucleophile that mediates the formation of said esters. 
     
     
         8 . The ester according to  claim 1 , wherein said ester has a general structure according to at least one of the following: 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         wherein R is either a methyl, ethyl, butyl or propyl group. 
       
     
     
         9 . The ester according to  claim 1 , wherein said ester is at least one of the following: