A series of 1-(2-nitrophenyl)-3,4-dihydroisoquinolines were reduced under very mild reaction conditions in the presence of Tin(II) chloride dihydrate (SnCl2Ě2H2O) to give 5,6-dihydroindazolo[3,2-a]isoquinolines 4a-h. A mechanism for this reaction is proposed. ... The synthesis of isoquinolines and their derivatives has received much attention1-5 due to their widespread occur- rence in nature6-8 and broad biological activities.9-15 The pyr- ...
