Pechmann Reaction in Chloroaluminate Ionic Liquid

Abstract

Substituted coumarins were synthesized in good yields via the Pechmann reaction in chloroaluminate ionic liquid. 1-Butylpyridinium chloroaluminate ionic liquid was used as a solvent cum catalyst for this condensation reaction.

ionic liquid - Pechmann reaction - coumarins

References

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<A NAME="RG19701ST-17">17</A>

Ionic melt was prepared following the procedure described previously, ref. [16b] .

<A NAME="RG19701ST-18">18</A>

Experimental Procedure: A mixture of phenol (10 mmol), ketoester (10 mmol) and the ionic liquid (8.7 mmol) was stirred at 130 °C in a pre-heated oil bath. After completion of the reaction at the desired time as indicated in the table, the reaction mixture was quenched by adding 6 M HCl. The solid product obtained was filtered off and recrystallized from appropriate solvents. The compounds are all well known and in agreement with spectral and physical data.