Because of their easy availability and their relative chemical stability, urea, formic acid, and glycine might have played a role in the assembly process of nucleobases. In this paper, a short reaction path is described to prepare hypoxanthine starting from the above mentioned precursors. The formation of hypoxanthine has been verified by high-resolution mass spectrometry with the 15N-labelled urea as starting material, and HPLC analysis. The yield of this condensation reaction has been determined spectrophotometrically.