1: 72 percent / various solvent(s) / 150 °C 2: 47 percent / 0.5N aq. HCl / acetone / 4 h / Ambient temperature 3: 42 percent / 0.1N aq. NH3 / diethyl ether 4: CH2Cl2 / 3 h / ice-bath 5: 60 percent / toluene / 1 h / 45 °C View Scheme