1: 4-methyl-benzaldehyde; phenylhydrazine in ethanol 0.5 h; 2: With tetrabutylammomium bromide; sodium carbonate in ethanol; dichloromethane; water T=0°C; 1 h; 3: aniline With hydrogenchloride; sodium nitrite in ethanol; dichloromethane; water T=20°C; 2 h;

1: p-tolualdehyde phenylhydrazone With tetrabutylammomium bromide; sodium carbonate in ethanol; dichloromethane T=0°C; 1 h; 2: benzene diazonium chloride in ethanol; dichloromethane; water T=20°C; 2 h; Further stages.;

hydrogenchloride; tetrabutylammomium bromide; sodium carbonate; sodium nitrite 2.) aq. CH2Cl2, 5 deg C to 15 deg C, 2 h;

1: 4-methyl-benzaldehyde; phenylhydrazine 2: [Ph-N2](+)

Tl(Oac)3; sodium chloride in water; acetic acid T=50°C; Rate constantMechanism;