potassium tert-butylate in dimethyl sulfoxide T=20°C; Cyclization; 0.666667 h;

1: triethylamine / CH2Cl2 / 2 h / 20 °C 2: 14.9 g / 10percent NaOH / H2O / 0.5 h 3: 100 percent / tetrabutylammonium bromide; K2CO3 / dimethylformamide / 20 °C 4: 63 percent / potassium tert-butoxide / dimethylsulfoxide / 0.67 h / 20 °C View Scheme

1: 100 percent / tetrabutylammonium bromide; K2CO3 / dimethylformamide / 20 °C 2: 63 percent / potassium tert-butoxide / dimethylsulfoxide / 0.67 h / 20 °C View Scheme

1: 14.9 g / 10percent NaOH / H2O / 0.5 h 2: 100 percent / tetrabutylammonium bromide; K2CO3 / dimethylformamide / 20 °C 3: 63 percent / potassium tert-butoxide / dimethylsulfoxide / 0.67 h / 20 °C View Scheme