1: With trifluoromethylsulfonic anhydride in dichloromethane T=20°C; 0.0833333 h; 2: With diethyl-1,4-dihydro-2,6-dimethyl-3,5-pyridine dicarboxylate in dichloromethane T=20°C; 1 h; Further stages.;

N-benzyl-trimethylammonium hydroxide in acetonitrile T=80°C; 25 h;