19.56 (pKa of conjugate acid in acetonitrile)[3] Pyrrolidine, also known as tetrahydropyrrole, is an organic compound with the molecular formula (CH2)4NH.
Pyrrolidine is prepared industrially by the reaction of 1,4-butanediol and ammonia at a temperature of 165–200 °C and a pressure of 17–21 MPa in the presence of a cobalt- and nickel oxide catalyst, which is supported on alumina.
[5] The reaction is carried out in the liquid phase in a continuous tube- or tube bundle reactor, which is operated in the cycle gas method.
The amino acids proline and hydroxyproline are, in a structural sense, derivatives of pyrrolidine.
[7] Relative to many secondary amines, pyrrolidine is distinctive because of its compactness, a consequence of its cyclic structure.