(5-chloro-2-methoxyphenyl)hydrazine

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a stirred suspension of 5-chloro-2-methoxyaniline (20.0 g, 126.98 mmol, 1.0 eq) in conc. HCl (250 mL) was added a solution NaNO2 (10.5 g, 152.38 mmol, 1.2 eq) in water (40 mL) dropwise at −5-0° C. until reaction mixture formed a clear solution. The reaction mixture was added dropwise to a stirred solution of SnCl2 (52.90 g, 279.36 mmol, 2.2 eq) in conc. HCl (250 mL) at −5° C. for 30 min. The solid precipitate obtained was filtered out and washed with excess of ice cold water to get (5-chloro-2-methoxyphenyl)hydrazine (25.3 g, 92%, off-white solid; TLC system: EtOAc/PE (3:7) Rf: 0.6). until reaction mixture formed a clear solution The solid precipitate obtained was filtered out washed with excess of ice cold water

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Tin(II)chloride dihydrate (SnCl2.2H2O, 121 g, 0.54 mol) was dissolved in 300 ml concentrated HCl at −72° C. Diazo Red RC (Azoic Diazo No. 10, C.I. 37120, Fast Red RC Salt, Aldrich Chemical Co., 50 g, 0.18 mole) was added in portions with vigorous mechanical stirring. After the addition was complete, the reaction was stirred at 0° C. for three hours. The tan solid was filtered and washed with concentrated HCl, then stirred for 30 minutes in a mixture of 500 ml of dichloromethane and 500 ml 2N NaOH. The organic layer was separated, dried over sodium sulfate, concentrated under vacuum, and the resulting oil crystallized from 100 ml of diethyl ether to yield (5-chloro-2-methoxyphenyl)hydrazine (26.4 g, 84%). 1H NMR (300 MHz, CDCl3) δ6.96 (1H, d, J=2.4 Hz), 6.70 (1H, dd, 8.4, 2.4 Hz), 6.65 (1H, d, J=8.4 Hz), 3.81 (3H, s). , 50 g, 0.18 mole) was added in portions with vigorous mechanical stirring After the addition The tan solid was filtered washed with concentrated HCl stirred for 30 minutes in a mixture of 500 ml of dichloromethane and 500 ml 2N NaOH The organic layer was separated dried over sodium sulfate concentrated under vacuum the resulting oil crystallized from 100 ml of diethyl ether