1: 66 percent / 1) KI, 2) HIO3 / 1) aq. EtOH, 2N acetic acid, reflux, 2) water, reflux, 2 h 2: aq. HCl; tetrahydrofuran / 3 h / Heating View Scheme

hydrazine hydrate

in tetrahydrofuran; hydrogenchloride 3 h; Heating;