One-pot synthesis of pyrrolo[2,1-a]isoquinoline-1-carboxamide derivatives via a four-component reaction

An effective route to functionalized 1,2,3, 10b-tetrahy-dropyrrolo[2,1-a]isoquinoline-1-carboxamide derivatives is described. This involves reaction of N-alkyl-3-oxobutanamides, which result from the addition of amines to diketene, and dibenzoyl-acetylene in the presence of isoquinoline. The reactive]:I intermediate obtained from the addition of isoquinoline to dibenzoyl-acetylene is trapped by OH acids such as N-alkyl-3-oxobutanamides to produce the pyrrolo[2,1-a]isoquinoline-l-carboxamide derivatives.