Figure 2. EI-mass spectra. a) antipyrine;b): 4-aminoantipyrine; c) methylaminoantipyrine; d) metamizole (dimethylaminoantipyrine)

From

The Analgesic Metamizole (Dipyrone) and Its Related Products Antipyrine, 4-Aminoantipyrine and 4-Methylaminoantipyrine. Part 1: Mass Spectrometric and Electrochemical Detection

Achim Habekost

World Journal of Chemical Education. 2018, 6(3), 134-144 doi:10.12691/wjce-6-3-6