The synthesis of triazoles (e.g., types I and II) has been previously
reported by our group.7,8 The open chain THIQ analogs of triazoles
13–24 (type I) were prepared through a sequential
sulfonation/reduction/diazotization/cycloaddition reactions (route
a; steps i–iv) as outlined in Scheme 1. In the same manner, the synthesis
of triazoles type II 25–31 and type III 32–35 was carried out
via route b (steps i–v) in which an additional step (i.e., step v) was
performed using the Pictet–Spengler reaction to form isoquinoline
ring (10) prior to steps ii–iv.