The Carbylamine reaction is a chemical test

Chemical test

In chemistry, a chemical test is a qualitative or quantitative procedure designed to prove the existence of, or to quantify, a chemical compound or chemical group with the aid of a specific reagent...

 for detection of primary amine

Amine

Amines are organic compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are derivatives of ammonia, wherein one or more hydrogen atoms have been replaced by a substituent such as an alkyl or aryl group. Important amines include amino acids, biogenic amines,...

s. In this reaction, the analyte is heated with alcoholic potassium hydroxide

Potassium hydroxide

Potassium hydroxide is an inorganic compound with the formula KOH, commonly called caustic potash.Along with sodium hydroxide , this colorless solid is a prototypical strong base. It has many industrial and niche applications. Most applications exploit its reactivity toward acids and its corrosive...

and chloroform. If a primary amine is present, the isocyanide is formed.

For example, the reaction with ethylamine:

The reaction with aniline:
The carbylamine test does not give a positive reaction with secondary and tertiary amines.