A 100 mg (0.13 mmol) portion of the as-synthesized crystal catalyst, 70 mmol of 2-butanone, and 70 mmol of ethylene glycol were introduced into 80 mmol of toluene, the latter was used as the solvent for a ketal formation reaction.
The reaction was refluxed at 110 C under Dean- Stark conditions for specified time intervals.
The catalyst was isolated by filtration and reused on subsequent reactions without
further treatment.
A 100 mg portion of SLUG-21 was also applied for an esterification between 70 mmol acetic acid and 70 mmol ethanol in 8 mL toluene. The reactants were refluxed for 8 h without further methods for water removal.
All product yields were determined by 1H NMR (Supporting Information).