Über thermische, eine Amino‐ Claisen ‐Umlagerung einschliessende. Reaktionen von N‐Propargyl‐naphthylaminen

N‐Propargyl‐1‐naphthylamine ( 1 ), the corresponding N‐butinylcompound 5 and N‐propargyl‐2‐naphthylamine ( 2 ) ‐ unlike N‐propargyl‐anilines ‐ on heating to 250° are converted to a mixture of py‐tetrahydro‐benzoquinolines and benzoquinolines (scheme 1). The mechanism of these reactions which are induced by a [3 s , 3 s ] rearrangement of the propargyl group and include a [1,5 s ] H‐shift is depicted in scheme 4. N‐Methylation of 1 and 2 reduces for steric reasons the rate of the [1,5 s ] H‐shifts; therefore ring closure of the allenylnaphthylamine intermediates to indols 13 and 14 is favoured (schemes 2 and 5).