The aldehyde remover may be one comprising a hydrazide compound or nitrogenous heterocyclic compound.

Disclosed is a nitrogenated heterocyclic compound represented by general formula (1).

A method for producing a tetrafluoro nitrogen-containing heterocyclic compound such as tetrafluoropyrrolidine with high yield at low cost.

The base may be a linear or branched primary to tertiary alkylamine having 1 to 10 carbon atoms, a nitrogenated heterocyclic compound having 2 to 20 carbon atoms or a nitrogenated hetero-aromatic cyclic compound having 2 to 20 carbon atoms.

Disclosed is an aryl-substituted nitrogen-containing heterocyclic compound represented by the formula (I) below or a pharmaceutically acceptable salt thereof.

The composition for foam production comprises: a thermoplastic elastomer having a side chain comprising an imino group and/or nitrogenous heterocycle and a carbonyl-containing group; and a blowing agent.