. . . . . . . "Appropriate bases are for example, alkali and earth alkaline metal carbonates, hydrogen carbonates and amines, e.g. sodium carbonate, potassium carbonate, sodium hydrogen carbonate, N,N-diethylethanamine, 4-ethylmorpholine, 1,4-diazabiclyco[2.2.2]octane, pyridine and the like bases." .