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Microwave-Assisted Hydrolysis of Ethyl Azolylacetates and Cinnamates with K2CO3: Synthesis of Potassium Carboxylates

Year: 2024

Type: article

Abstract: In this study, the hydrolysis of ethyl azolylacetates and ethyl cinnamates using K2CO3/ethanol under microwave irradiation was developed. For this purpose, ethyl azolylacetates were first synthesized by nucleophilic substitution between the corresponding azole and ethyl bromoacetate under sonication at 50 °C for 3 h, yielding derivatives with 10–92% chemical yields, while ethyl cinnamates were obtained by a microwave-assisted Horner–Wadsworth–Emmons (HWE) reaction of triethyl phosphonoacetate with a variety of aryl aldehydes at 140 °C for 20 min, yielding derivatives with moderate to high yields (67–98%). Initially, the optimization of the hydrolysis reaction was performed using ethyl pyrazolylacetate as a model starting material while varying the temperature, time, and base equivalents; the best results were achieved by carrying out the reaction at 180 °C for 20 min with 3.0 eq of K2CO3. This simple and greener method facilitated the synthesis of potassium carboxylates in moderate to high yields, 80–98% for azolyl derivatives and 73–98% for cinnamate derivatives. The structures of all potassium carboxylates were confirmed by FTIR, 1H, 13C NMR, and HRMS.

Source: ACS Omega

DOI: 10.1021/acsomega.4c05596