REINVESTIGATION OF THE PICTET-GAMS ISOQUINOLINE SYNTHESIS .1. CONSEQUENCES OF OXAZOLINE RATHER THAN ISOQUINOLINE FORMATION

Cyclisation of various 2-acylamino-1-arylalkan-1-ols under typical Pictet-Gams conditions yields Δ2-oxazolines and not isoquinolines as previously reported. Compounds originally formulated as isoquinolines and isoquinoline hydrochlorides are shown to be derivatives of 2-amino-1-phenylalkan-1-ols, and to have arisen through ring-cleavage of the Δ2-oxazolines during the isolation procedure. Their mode of formation is fully explained.