1: 1n NaOH, 1n HCl, HOBt hydrate, DCC / 1) 1h acetone, 2) -10deg C, DMF, 3) 18h to RT 2: 90 percent / 11.8n HCl / methanol 3: 82 percent / HOBt hydrate, pentachlorophenol, triethylamine / dimethylformamide / 19 h / Ambient temperature 4: 94 percent / 7n HCl / methanol / 0.08 h / Ambient temperature 5: 1) 9.2n HCl, isoamyl nitrite, 2) Et3N / 1) DMF, THF, 30 min, -47 deg C, 2) 48h, -5 deg C 6: 99percent hydrazine hydrate / 1) -20 deg C, Et3N, THF, 2) 48h to -5deg C, DMF 3) 20h to -5deg C 7: 1) 6.1n HCl, isoamyl nitrite, 2) triethylamine / 1) -30deg C, THF, 30 min; 2) -45deg C, DMF, 15h between -5deg C to 0deg C View Scheme

Multi-step reaction with 7 steps 1: 1n NaOH, 1n HCl, HOBt hydrate, DCC / 1) 1h acetone, 2) -10deg C, DMF, 3) 18h to RT2: 90 percent / 11.8n HCl / methanol3: 82 percent / HOBt hydrate, pentachlorophenol, triethylamine / dimethylformamide / 19 h / Ambient temperature4: 94 percent / 7n HCl / methanol / 0.08 h / Ambient temperature5: 1) 9.2n HCl, isoamyl nitrite, 2) Et3N / 1) DMF, THF, 30 min, -47 deg C, 2) 48h, -5 deg C6: 99percent hydrazine hydrate / 1) -20 deg C, Et3N, THF, 2) 48h to -5deg C, DMF 3) 20h to -5deg C7: 1) 6.1n HCl, isoamyl nitrite, 2) triethylamine / 1) -30deg C, THF, 30 min; 2) -45deg C, DMF, 15h between -5deg C to 0deg C