Ramini test

Two color tests to distinguish primary and secondary aliphatic amines have been available for many years, although they have not been widely used. More recently, these tests have been extended to primary, secondary, and tertiary aromatic amines. No attempt is made here to explain the complex color-forming reactions that occur. However, they most likely involve the reaction of the amine with either acetone, the Ramini test, or acetaldehyde, the Simon test, and the interaction of the resulting products with sodium nitroprusside to form colored complexes. 

Ramini Test. To 1 mL of the sodium nitroprusside reagent, add 1 mL of water, 0.2 mL (5 drops) of aoetone, and about 30 mg of an amine. In most oases, the oharaoteristio oolors given in Figure 25.7 appear in a few seoonds, although in some instanoes up to about 2 min may be neoessary. 

To apply these tests to an unknown amine, the conventional Ramini or Simon tests are first performed. These will give positive results in the cases of primary and secondary aliphatic amines. If these tests are negative and an aromatic amine is suspected, the modified versions of these tests are then performed. Reference to Figure 25.7 is helpful for interpreting the results of these tests. 

Conventionai Tests. Prepare the sodium nitroprusside reagent for use in both the oonventional Ramini and Simon tests by dissolving 0.4 g of sodium nitroprusside (Na2[Fe(NO)(CN)5] 2 H2O in 10 mL of 50% aqueous methanol. 

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