. . . "As an acceptor there may be used, for example, an alkali or alkaline earth metal salt of carbonic acid, for example sodium or potassium bicarbonate or carbonate or calcium carbonate, a tertiary organic base, for example dimethylaniline, pyridine or triethylamine or an excess of the compound of the formula III or V. The compounds of the present invention are weak bases which may be converted with a" . . . . .