where the methyl palmitate product formed a solid upon cooling
(methyl palmitate has a melting point of 29–31 °C). The bottom DES
layer remained liquid; thus the reaction products are simple to separate
for analysis. 1H NMR analysis in CDCl3 of the top layer indicated complete
conversion to methyl palmitate. 1H NMR analysis of the bottom
layer in D2O showed the characteristic peaks for the DES plus excess
methanol.