1955 年 75 巻 2 号 p. 232-233
Specific color reaction for diethylamine (I) is to mix 1 drop of (I) or its hydrochloride solution with 1 drop of 5% sodium nitroprusside (II) solution, 1 drop of 5% potassium ferricyanide (III) solution, and 1 drop of 2N Na2CO3 solution, and warming the mixture in a water bath (90°) for about 15 seconds by which the reaction mixture acquires a pale brownish yellow color which turns from indigo blue, through purple, to purplish red on cooling in air or water. The mechanism of this coloration may be assumed as the oxidation of (I) by (II) and (III) to form acetaldehyde which reacts with (I) and (II) to give the color reaction peculiar to aliphatic secondary amines.