1: 5-chloro-1,3-dihydro-2H-indol-2-one With phosphorus(III) oxychloride in 1,2-dichloro-ethane Vilsmeier-Haack-Arnold reaction; 0.5 h; Heating; 2: N-(chloromethylene)-N-methylmethanaminium chloride in 1,2-dichloro-ethane 20 h; Heating;