EDC/NHS is generally used for amide coupling chemistry; however, this can be used for ester coupling as well. Below, I have mentioned some key points to get good yield %

Few key points

· EDC-HCl is moisture sensitive. Allow EDC-HCl to equilibrate to room temperature before opening vial.

· Except as indicated in this protocol, avoid using buffers that contain DTT, EDTA, or β-Mercaptoethanol, as these can interfere with conjugation reaction.

· Use Conjugation Buffer: 100 mM MES, 500 mM NaCl, pH 6.0.

· Weigh out 0.8 mg EDC-HCl and 2.2 mg of Sulfo-NHS and add directly to the -COOH/-OH reagent solution.

· Allow the reaction at room temperature for 30 min.

It surely uses EDC/NHS for coupling of COOH and OH. However, I prefer using DCC/DMAP for this coupling.

EDC/NHS is used as a coupling agent for COOH-NH2 coupling, it can be used for COOH and other hydrogen-donor moieties such as amine, hydroxyl or thiol group . I think Using this coupling agent it may be possible to synthesize ester compound.

You may follow the attached article, that may be helping material for your research. Thank you and best of luck.

Article Graphene oxide based crosslinker for simultaneous enhancemen...

EDC/DMAP is a good option for esterification as its urea biproduct is water soluble, hence can easily remove during work up.