1: NH3, H2S / methanol 2: ethanol 3: NaOH / methanol; H2O 4: (i) Et3N, ClCO2Et, THF, (ii) NaN3, H2O, (iii) /BRN= 385737/, AcOH 5: aq. HCl View Scheme

1: NH3, H2S / methanol 2: ethanol 3: NaOH / methanol; H2O 4: (i) Et3N, ClCO2Et, THF, (ii) NaN3, H2O, (iii) /BRN= 385737/, AcOH 5: aq. HCl 6: methanol; diethyl ether View Scheme