An imine with the general formula R1R2C=NR3, where R1, R2, and R3 are alkyl or aryl groups. They are formed by a condensation reaction between an aromatic amine and an aldehyde or ketone, for example
The compounds are often crystalline and are used in organic chemistry for characterizing aromatic amines (by preparing the Schiff’s base and measuring the melting point). They are named after the German chemist Hugo Schiff (1834–1915).