Decarboxylation in the synthesis of 4‐alkyl‐, 4‐alkenyl‐ and 4‐acylpyrimidines

Abstract

Decarboxylation of allylic esters of 4-carboxypyrimidines in toluene at 111 °C in the presence of a Pd(0) catalyst, gives a mixture of a 4-alkenylpyrimidine and a pyrimidine unsubstituted in the 4-position. If the decarboxylation is carried out in the presence of benzaldehyde, then benzaldehyde is added to the 4-position. Decarboxylation of 4-carboxypyrimidines in the presence of different electrophiles, results in incorporation of the electrophile into the 4-position together with a pyrimidine unsubstituted in the 4-position. Use of microwave irradiation enhances the rate of the decarboxylations.

Microwave-assisted decarboxylation of bicyclic 2-pyridone scaffolds and identification of Aβ-peptide aggregation inhibitors

“…3). This finding opens up possibilities to react the intermediate anion with an electrophile, leading to the formation of new interesting derivatives, 28 currently under investigation in our laboratories.…”

“…Microwave-assisted synthesis has previously been successful in both cyanation and aminomethylation reactions of 2pyridones. 24 Beneficial use of the microwave technique for decarboxylation reactions has also been reported [25][26][27][28] and was now applied for the decarboxylations of the 2-pyridones 11a-g (Scheme 1). Thus, after some adjustment of the reaction conditions, it was found that CuCN (10 eq.)…”