Figure 2. Synthesis of TDRL-505 analogs.
Reagents and conditions: (a) DIEA, DMAP, DCM, rt, 2 h, 90–100%. (b) (i) DMF, POCl3, 0 °C, 20 min, (ii) Amide, 110 °C, 2.5 h, 44–64%. (c) NaOH 10%, EtOH, 45 °C, 45 min. (d) H2N-NH2.H2O, EtOH, reflux, 1.5 h, 73–81% (over 2 steps). (e) CHCl3, reflux 1.5 h, 40–72%.