1: With sodium hydroxide; water in methanol T=78 - 80°C; 1 h; 2: With acetic acid in ethyl acetate T=10 - 15°C; pH=4 - 5;

lithium hydroxide in ethanol T=80°C; 3 h;

1: With sodium hydroxide; ethanol; water 24 h; Heating / reflux; 2: With hydrogenchloride in ethanol; water pH=4 - 4.5;

sodium hydroxide in ethanol

1: SOCl2, DMF / toluene / 0.5 h / Heating 2: NaN3 / acetone; H2O / 1 h 3: 1.5 h / Heating 4: 85 percent / K2CO3 / acetonitrile / 4 h / Heating 5: 77 percent / 30percent ethanolic HCl / ethyl acetate / 1 h / Ambient temperature 6: 1.) FeCl3*6H2O, activated carbon, 2.) hydrazine monohydrate / 1.) MeOH, THF, reflux, 30 min, 2.) MeOH, THF, reflux, 14 h 7: 91 percent / acetic acid / 0.67 h / 80 - 90 °C 8: 100 percent / trimethyltin azide / toluene / 29 h / Heating 9: 85 percent / 1 N aq. NaOH / methanol / 1 h / 80 - 90 °C View Scheme

1: NaN3 / acetone; H2O / 1 h 2: 1.5 h / Heating 3: 85 percent / K2CO3 / acetonitrile / 4 h / Heating 4: 77 percent / 30percent ethanolic HCl / ethyl acetate / 1 h / Ambient temperature 5: 1.) FeCl3*6H2O, activated carbon, 2.) hydrazine monohydrate / 1.) MeOH, THF, reflux, 30 min, 2.) MeOH, THF, reflux, 14 h 6: 91 percent / acetic acid / 0.67 h / 80 - 90 °C 7: 100 percent / trimethyltin azide / toluene / 29 h / Heating 8: 85 percent / 1 N aq. NaOH / methanol / 1 h / 80 - 90 °C View Scheme

1: concd. H2SO4 / methanol 2: SOCl2, DMF / toluene / 0.5 h / Heating 3: NaN3 / acetone; H2O / 1 h 4: 1.5 h / Heating 5: 85 percent / K2CO3 / acetonitrile / 4 h / Heating 6: 77 percent / 30percent ethanolic HCl / ethyl acetate / 1 h / Ambient temperature 7: 1.) FeCl3*6H2O, activated carbon, 2.) hydrazine monohydrate / 1.) MeOH, THF, reflux, 30 min, 2.) MeOH, THF, reflux, 14 h 8: 91 percent / acetic acid / 0.67 h / 80 - 90 °C 9: 100 percent / trimethyltin azide / toluene / 29 h / Heating 10: 85 percent / 1 N aq. NaOH / methanol / 1 h / 80 - 90 °C View Scheme

1: 85 percent / K2CO3 / acetonitrile / 4 h / Heating 2: 77 percent / 30percent ethanolic HCl / ethyl acetate / 1 h / Ambient temperature 3: 1.) FeCl3*6H2O, activated carbon, 2.) hydrazine monohydrate / 1.) MeOH, THF, reflux, 30 min, 2.) MeOH, THF, reflux, 14 h 4: 91 percent / acetic acid / 0.67 h / 80 - 90 °C 5: 100 percent / trimethyltin azide / toluene / 29 h / Heating 6: 85 percent / 1 N aq. NaOH / methanol / 1 h / 80 - 90 °C View Scheme

1: 91 percent / acetic acid / 0.67 h / 80 - 90 °C 2: 100 percent / trimethyltin azide / toluene / 29 h / Heating 3: 85 percent / 1 N aq. NaOH / methanol / 1 h / 80 - 90 °C View Scheme

1: 1.) FeCl3*6H2O, activated carbon, 2.) hydrazine monohydrate / 1.) MeOH, THF, reflux, 30 min, 2.) MeOH, THF, reflux, 14 h 2: 91 percent / acetic acid / 0.67 h / 80 - 90 °C 3: 100 percent / trimethyltin azide / toluene / 29 h / Heating 4: 85 percent / 1 N aq. NaOH / methanol / 1 h / 80 - 90 °C View Scheme