1: N,N-dimethyl-formamide With bis(trichloromethyl) carbonate in 1,2-dichloro-ethane T=0 - 20°C; Vilsmeier-Haack reaction; 2: p-chlorobenzalacetone in 1,2-dichloro-ethane T=20 - 60°C; Vilsmeier-Haack reaction; 3: malononitrile in 1,2-dichloro-ethane T=60°C; Reflux;