1: 93 percent / NaNO2 / acetic acid; acetic anhydride / 1.) 0 deg C, 16 h, 2.) room temperature, 8 h 2: 95 percent / CH2Cl2 View Scheme

sodium nitrite in acetic anhydride; acetic acid 1.) 0 deg C, 16 h, 2.) room temperature, 8 h;