hydrogenchloride 6 h; Heating;

1: 45 percent / 4.5 M aq. HCl / 6 h / Heating 2: (COCl)2, DMF / CH2Cl2 / 18 h / Ambient temperature 3: 1.) isopropylmagnesium chloride / 1.) THF, -78 deg C, 30 min, 2.) THF, from -78 deg C to RT View Scheme