# Succinic anhydride esterification won't go forward

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?

• Addition of catalytic pyridine should assist it. – Waylander Feb 9 at 22:30
• Do you use solvent? if so, what is it? Would you please include those in your question? – Mathew Mahindaratne Feb 10 at 0:46

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).