合成路线1

Vilsmeier reaction of 4-methoxy-3-pyrrolin-2-one (I) with phosphoryl bromide and N,N-dimethylformamide, followed by basic hydrolysis, provides 5-bromo-3-methoxypyrrole-2-carbaldehyde (II), which is then subjected to Suzuki coupling with 1-Boc-2-indoleboronic acid (III) to afford the indolyl pyrrolealdehyde (IV). In a related method, intermediate (IV) is prepared by reaction of pyrrolinone (I) with phosphoryl bromide and diethylformamide, followed by Suzuki coupling of the resulting bromopyrrole (V) with the indoleboronic acid (III) and basic enamine hydrolysis. The title compound is then obtained by simultaneous condensation and deprotection of pyrrole aldehyde (IV) with 2,4-dimethylpyrrole (VI) in methanolic hydrogen chloride (1). Scheme 1.