5b, c and the (4-morpholiny1) benzeneacetonitrile 7c do not react. The (1-piperidiny1) benzeneacetonitrile 7b yields in refluxing toluene in the presence of zinc chloride the pyrido [l, 2-a] indole 14b and, by HCN elimination, pyrido [l, 2-a] indole 15b. Under these ...