Hexacyclododecylamines with Sigma-1 Receptor Affinity and Calcium Channel Modulating Ability

Scheme 3 Reagents and conditions: (i) Formic acid, 110 °C for 2 h, 74%; (ii) DMF, 3-chloropropylamine, NaOH, 80-90 °C, 2 h, 69%; (iii) THF, -10 °C, 10 min; (iv) benzene, Dean-Stark, 1 h; (v) MeOH/AcOH, NaCNBH₃, rt, 2 h, 13%; (vi) THF/MeOH, NaBH₄, rt, 8 h 35%;