in xylene acid heated until dissolved (80-85°C), further heating (90-95°C), alcoholate addn., stirring (90-95°C, 3-4 h); drying in vacuum; elem. anal.;

in xylene acid heated until dissolved (80-85°C), further heating (90-95°C), alcoholate addn., stirring (90-95°C, 3-4 h); drying in vacuum; elem. anal.;