"Suitable bases are, for example, organic amines, such as trialkylamines, morpholine, piperidine or pyridine, and also ammonium, alkali metal or alkaline earth metal hydroxides, carbonates and bicarbonates, in particular sodium hydroxide and potassium hydroxide, sodium carbonate and potassium carbonate and sodium bicarbonate and potassium bicarbonate, alkali metal or alkaline earth metal alkoxides," . . . . . . . . . . . . . . . .