1: 4-(2-oxo-1,2-dihydro-quinolin-6-yloxy)-butyric acid With 1,8-diazabicyclo[5.4.0]undec-7-ene; isobutyl chloroformate in chloroform T=20°C; Cooling with ice; 2: N-cyclohexyl-N-methylamine in chloroform T=20°C; 3 h;

pyridine in tetrahydrofuran

toluene-4-sulfonic acid in tetrahydrofuran; toluene 48 h; Heating; Yield given;

1: aq. Na2CO3 / tetrahydrofuran / 1 h / Ambient temperature 2: 83 percent / pyridine / ethanol / Heating 3: FeSO4, aq. conc. NH3 / 0.25 h / Heating 4: TsOH / toluene; tetrahydrofuran / 48 h / Heating View Scheme

1: 95 percent / K2CO3 / dimethylformamide / 1 h / 100 °C 2: 96 percent / aq. KOH / ethanol 3: oxalyl chloride / benzene; dimethylformamide / 1 h / Ambient temperature 4: aq. Na2CO3 / tetrahydrofuran / 1 h / Ambient temperature 5: 83 percent / pyridine / ethanol / Heating 6: FeSO4, aq. conc. NH3 / 0.25 h / Heating 7: TsOH / toluene; tetrahydrofuran / 48 h / Heating View Scheme

1: 96 percent / aq. KOH / ethanol 2: oxalyl chloride / benzene; dimethylformamide / 1 h / Ambient temperature 3: aq. Na2CO3 / tetrahydrofuran / 1 h / Ambient temperature 4: 83 percent / pyridine / ethanol / Heating 5: FeSO4, aq. conc. NH3 / 0.25 h / Heating 6: TsOH / toluene; tetrahydrofuran / 48 h / Heating View Scheme

1: FeSO4, aq. conc. NH3 / 0.25 h / Heating 2: TsOH / toluene; tetrahydrofuran / 48 h / Heating View Scheme

1: oxalyl chloride / benzene; dimethylformamide / 1 h / Ambient temperature 2: aq. Na2CO3 / tetrahydrofuran / 1 h / Ambient temperature 3: 83 percent / pyridine / ethanol / Heating 4: FeSO4, aq. conc. NH3 / 0.25 h / Heating 5: TsOH / toluene; tetrahydrofuran / 48 h / Heating View Scheme

1: aq. Na2CO3 / tetrahydrofuran / 1 h / Ambient temperature 2: 83 percent / pyridine / ethanol / Heating 3: FeSO4, aq. conc. NH3 / 0.25 h / Heating 4: TsOH / toluene; tetrahydrofuran / 48 h / Heating View Scheme

1: 83 percent / pyridine / ethanol / Heating 2: FeSO4, aq. conc. NH3 / 0.25 h / Heating 3: TsOH / toluene; tetrahydrofuran / 48 h / Heating View Scheme