1: With sulfuric acid; sodium nitrite in water; N,N-dimethyl-formamide T=0°C; 1.5 h; 2: With urea in water; N,N-dimethyl-formamide T=20 - 90°C; 0.416667 h; 3: With sodium hydrogencarbonate in water; N,N-dimethyl-formamide Product distribution / selectivity;