Propyleneimine is the organic compound with the formula CH3CH(NH)CH2. It is a secondary amine and the smallest chiral aziridine (ring containing C2N). It is a colorless liquid. Propyleneimine is the organic compound with the formula CH3CH(NH)CH2. It is a secondary amine and the smallest chiral aziridine (ring containing C2N). It is a colorless liquid. The compound is mainly of academic interest, e.g. for the synthesis of dendrimers, a process that exploits the tendency of aziridines to undergo ring-opening reactions.