1: 5,6-Dimethoxy-1-oxoindane-2-carboxylic acid methyl ester With potassium carbonate in N,N-dimethyl-formamide T=20°C; 0.5 h; 2: 4-iodomethyl-piperidine-1-carboxylic acid tert-butyl ester in DMF (N,N-dimethyl-formamide) T=20 - 50°C; 5.5 h;