in dimethyl sulfoxide T=80°C; 1.5 h;

potassium tert-butylate in dimethyl sulfoxide 3 h; Ambient temperature;

1: 1) KOH, 2) piperidine / 1) ethanol, 12 h, room temperature, 2) 130 deg C, pyridine 2: 76 percent / dimethylsulfoxide / 1.5 h / 80 °C View Scheme