potassium carbonate in tetrahydrofuran; N,N-dimethyl-formamide 15 h; Heating / reflux;

sodium hydroxide; tetra(n-butyl)ammonium hydroxide in dichloromethane 1.) 10 min, 2.) 5 h;

1: 71 percent / KF*2H2O, tetrabutylammonium chloride / 30 h / Heating 2: 74 percent / 1.) tetrabutylammonium hydroxide, 50percent aq. NaOH / CH2Cl2 / 1.) 10 min, 2.) 5 h View Scheme

hydrogen; nickel in methanol T=100°C; P=114000 Torr; 3 h; Yield given;