1: TsOH*H2O / ethanol / 1.) 20 deg C, 1 h, 2.) 4 deg C, overnight 2: 69 percent / t-BuOK / dimethylformamide / 1 h / 20 °C 3: 80 percent / dimethylformamide / 8.5 h / 120 °C 4: 1.) 33percent MeNH2, 2.) 4 M HCl / 1.) EtOH, r.t., 1 h, 2.) EtOH, EtOAc, r.t., overnight View Scheme

1: TsOH*H2O / ethanol / 1.) 20 deg C, 1 h, 2.) 4 deg C, overnight 2: 69 percent / t-BuOK / dimethylformamide / 1 h / 20 °C 3: 80 percent / dimethylformamide / 8.5 h / 120 °C 4: 1.) 33percent MeNH2, 2.) 4 M HCl / 1.) EtOH, r.t., 1 h, 2.) EtOH, EtOAc, r.t., overnight 5: 48 percent / 1-hydroxybenzotriazole hydrate, dicyclohexylcarbodiimide, N-ethylmorpholine / tetrahydrofuran / 64 h / Ambient temperature 6: H2 / 10percent Pd/C / ethanol / 16 h 7: 1-hydroxybenzotriazole hydrate, dicyclohexylcarbodiimide, N-ethylmorpholine / tetrahydrofuran / 16 h / Ambient temperature View Scheme

1: TsOH*H2O / ethanol / 1.) 20 deg C, 1 h, 2.) 4 deg C, overnight 2: 69 percent / t-BuOK / dimethylformamide / 1 h / 20 °C 3: 80 percent / dimethylformamide / 8.5 h / 120 °C 4: 1.) 33percent MeNH2, 2.) 4 M HCl / 1.) EtOH, r.t., 1 h, 2.) EtOH, EtOAc, r.t., overnight 5: 48 percent / 1-hydroxybenzotriazole hydrate, dicyclohexylcarbodiimide, N-ethylmorpholine / tetrahydrofuran / 64 h / Ambient temperature View Scheme