Carboxylic acids heteroaromatic, reduction

Aromatic and heteroaromatic esters can be electrochemically reduced to benzyl alcohols, similar to the carboxylic acids. One example is the cathodic reduction of dimethyl terephthalate531 . 

Yields or Aldehydes from Electrolytio Reduction of Heteroaromatic Carboxylic Acid Derivatives ... 

The ideas for delocalization of nitrogen lone pair electron density into an aromatic or heteroaromatic system were pursued through reduction of acylated pyrazoles and imidazoles to aldehydes in high yield. 3,5-Dimethyl-A -acylpyrazoles are easy to prepare and afford 77-96% yields of aldehydes with LiAlH4 in diethyl ether at 0 Further examples of this reaction have appeared.Although these later publications commented unfavorably on the ability of LiAlH4 to reduce acyl imidazoles to aldehydes (low yields), other workers have demonstrated that yields of 60-80% could be attained at temperatures of -20 to 4-20 °C in diethyl ether.It was considered that the earlier failure may have been caused by the presence of impurities in the acyl imidazoles. The latter are easy to prepare from the parent carboxylic acid and A jV -carbonyldiimidazole. 

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