N,N-dimethyl acetamide in chloroform; acetone T=60°C; 4 h;

1: 93 percent / SnCl2*2H2O, conc. hydrochloric acid / ethanol / 6 h / Heating 2: 90 percent / conc. hydrochloric acid, NaNO2 / H2O / 4 h / Ambient temperature 3: 80 percent / N,N-dimethylacetamide (DMA) / acetone; CHCl3 / 4 h / 60 °C View Scheme