3-Methoxybenzylhydrazinedihydrochloride was prepared as follows: a solution of 3-methoxybenzyl chloride (5.0 g, 32 mmol) in ethanol (15 ml) was added dropwise to a solution of hydrazine monohydrate (10 g, 0.2 mol) in ethanol (35 ml) under heated reflux over 30 minutes. The reflux was continued for another 2 h before the solvent was removed under reduced pressure. The oily residue was extracted with ether (2 30 ml), dried, and the solvent was removed under reduced pressure, and the residue obtained was chromatographed with chloroform:methanol (20:1) onto silica gel (40 g) to give a crude fraction containing the target compound. Then the target compound 3-methoxybenzylhydrazine dihydrochloride (2.9 g, 60%) was obtained by distillation (120-123C/1-2 mmHg) as a colorless oil.
