1: N,N-dimethyl-formamide With trichlorophosphate T=-10°C; Vilsmeier-Haack reaction; Reflux; 2: 7-methoxy-1-oxo-1,2,3,4-tetrahydronaphthalene in N,N-dimethyl-formamide Vilsmeier-Haack reaction; 2 h; Reflux; 3: With water; sodium acetate in N,N-dimethyl-formamide Vilsmeier-Haack reaction;