Scheme 8.
Synthesis of compound 22. Reagents and conditions: (a) MsCl, Et3N, DCM, 0 °C to rt, 71 %; (b) ethane-1,2-diamine, NBS, DCM, 0 °C to rt, 89 %; (c) KOH, MeOH, rt, 15 %.
Synthesis of compound 22. Reagents and conditions: (a) MsCl, Et3N, DCM, 0 °C to rt, 71 %; (b) ethane-1,2-diamine, NBS, DCM, 0 °C to rt, 89 %; (c) KOH, MeOH, rt, 15 %.