Decarboxylated Methoxatin Analogues. Synthesis of 7- and 9-Decarboxymethoxatin

Article abstract of DOI:10.1021/jo00386a010

A total synthesis of two monodecarboxylated analogues of methoxatin (1) is described.The synthesis of 9-decarboxymethoxatin (4) was achieved starting with 8-hydroxyquinoline, constructing an appropriately substituted quinolylhydrazone of ethyl pyruvate with a Japp-Klingemann reaction and annulating the remaining pyrrole ring through a Fischer indole synthesis.The synthesis of 7-decarboxymethoxatin (3) first necessitated the construction of an appropriate indole from which the remaining pyridine ring could be annulated via a Doebner reaction.