Unambiguous Synthesis of 1-(7-Indenyloxy)-3-isopropylamino-2-propanol Hydrochloride and Its 4-Indenyloxy Isomer, Potent β-Adrenergic Blocking Agents

Abstract

1-(7-Indenyloxy)-3-isopropylamino-2-propanol hydrochloride (Ia) and its 4-indenyloxy isomer (IIa) were synthesized through the sequence of reactions in which possible isomerization of the indene nucleus was prevented by avoiding alkaline conditions. By referring to these standards, the preparation (YB-2) synthesized by the previously described method was found to be a 2 : 1 mixture of Ia and IIa. tert-Butyl analogue of Ia and IIa (Ib, IIb) was also prepared similarly. Biological activities of Ia, IIa were compared with those of YB-2.