1: 4-Bromophenylhydrazine hydrochloride With trifluoroacetic acid in toluene; acetonitrile T=35°C; 2: cyclohexanecarbaldehyde in toluene; acetonitrile T=20 - 35°C; 8 h; 3: With methanol; sodium tetrahydroborate in toluene; acetonitrile T=-10 - 0°C; 1.5 h;