1: N,N-dimethyl-formamide With trichlorophosphate T=0°C; Vilsmeier-Haack Formylation; 0.333333 h; 2: 6-methyl-1H-indole in N,N-dimethyl-formamide T=35°C; Vilsmeier-Haack Formylation; 1 h; 3: With sodium hydroxide in water; N,N-dimethyl-formamide 1 h; Reflux;

formic acid; hydroxylamine hydrochloride; sodium formate 1 h; Heating / reflux;

hydroxylamine hydrochloride; sodium acetate in ethanol T=22°C; 3 h;