Compounds IIa-e give a blue color with iron chloride, in contrast to the acid I which gives a red color, and this enables the course of the reaction to be followed. Compounds IIa-e are amino acids and form salts with alkalis; the hydrochlorides are easily decomposed because the amino group is weakly basic: From dilute acid solutions of salts only the free bases can be obtained. An exception is the diaminocarboxylic acid betaine IIe which has a ...
