1: sodium nitrite; acetic acid; aqueous sulfuric acid / 0 °C / Diazotization.Reagens 4: wss. Hypophosphorigsaeure 2: Raney nickel; ethanol View Scheme

1: 1.) hydrochloric acid, sodium nitrite; 2.) cuprous chloride / 1.) glacial acetic acid, water, 0 deg C, 15 min; 2.) r.t., overnight 2: 55 percent / H2 / Raney nickel / ethanol / 7 h / 760 Torr View Scheme

sulfuric acid; acetic acid; sodium nitrite T=0°C; Diazotization.Reagens 4: wss. Hypophosphorigsaeure;