1,8-diazafluorenone and related compounds. A new reagent for the detection of (α-amino acids and latent fingerprints.

1,8-Diazafluorenone (DFO) reacts with (α-amino acids and their esters via imine formation to give decarboxylated azomethine ylides and ester substituted azomethine ylides respectively. In the presence of N-methylmaleimide these azomethine ylides undergo stereospecific cycloaddition via endotransition states. Analogues of DFO give similar cycloadducts. In the absence of dipolarophiles the α amino acids and DFO give a red fluorescent dye thus providing a sensitive method for detecting latent fingerprints on paper.