Synthesis of N-substituted analogues of 1a
aReagents and conditions: (a) 2-(1,3-dioxoisoindolin-2-yl)acetaldehyde, Na(OAc)3BH, DCE, CH3COOH, RT, 12 h (b) hydrazine, EtOH, reflux, 3 h; (c) 1,4-Cyclohexanedione monoethyleneketal, Na(OAc)3BH, CH3COOH, dichloroethane, RT, 12h ; (d) 3N HCl, diethylether, RT, 2 h; (e) indole, pyrrolidine, EtOH, reflux, 24 h.