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I'm trying to react succinic anhydride with a decyl alcohol to produce mono-decyl succinate. Literature and Google searches suggest that the monoesterification should proceed without catalyst. However I'm failing to get the reactions going. Reactions were in reflux, $\pu{80-140 ^\circ C}$ at $\pu{1 atm}$.
Any suggestions if anhydride esterifications even needs a catalyst? Would a solvent help?
The monoesters of succinic acid can be prepared using Steglich esterification method (Ref.1,2), which is specially suitable for alcohols with the $\ce{OH}$ functional group is in steric hindrance. In this method, dicyclohexylcarbodiimide (DCC) as the coupling reagent and 4-dimethylaminopyridine (DMAP) as a catalyst are used. The reference 1 gave a typical procedure as follows:
To a stirred solution of 10mmol carboxylic acid in $\pu{lO ml}$ anhydrous $\ce{CH2Cl2}$ (in the case of sparingly soluble acids, in DMF) is added $\pu{30-110 mg}$ DMAP and $\pu{20-40 mmol}$ alcohol or thiol ($\pu{10 mmol}$ with alcohols or thiols which are not easily removable without significant loss; $\pu{3.4 mmol}$ with glycerol). DCC is added to the reaction mixture at OT, which is then stirred for $\pu{5 min}$ at $\pu{0 ^\circ C}$ and $\pu{3 h}$ at $\pu{20 ^\circ C}$. Precipitated urea is then filtered off and the filtrate evaporated down in vacuo. The residue is taken up in $\ce{CH2Cl2}$ and, if necessary, filtered free of any further precipitated urea. The $\ce{CH2Cl2}$ solution is washed twice with $\pu{0.5 N}$ $\ce{HCl}$ and with saturated $\ce{NaHCO3}$ solution, and then dried over $\ce{MgSO4}$. The solvent is removed by evaporation and the ester isolated by distillation or recrystallization. Crystalline products can be obtained in pure form by filtration on a short silica gel column (eluent: $\ce{CH2Cl2}$ or $\ce{CHCl3}$).
For example, recently, this method has successfully used to couple Vitamin $\mathrm{D_2}$ to succinic anhydride in order to achieve succinic monoester of Vitamin $\mathrm{D_2}$ (Ref.3). However, there is an US patent publication revealing cheap solvent free method using alkali salt bases such as $\ce{NaOAc, KOAc, Na2CO3}$, and $\ce{K2CO3}$ as catalysts to efficiently prepare mono alkyl esters from cyclic anhydrides (Ref.4).
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