Some ketimines prepared by thermal decarboxylation of amino-acids in the presence of aromatic ketones, or directly from the corresponding amines, are described. In the case of β-hydroxy-amines, ring closure takes place to give oxazolidines. Aromatic ketimines derived from o-hydroxyacetophenone react with phenyl isocyanate to give coumarin derivatives. Aldimines prepared from o-and p-hydroxy- and -methoxy-substituted benzaldehydes react with phenyl isocyanate to give s-triazine derivatives.