Figure shows stacked 1 H-NMR spectra taken over the course of the reaction with the atoms in the reactant (MA) and product coloured like their corresponding signal. The concentration of MA is calculated based on the decrease of the signal at 5.87 ppm (purple). The concentration of the The first spectrum starts from the bottom. In methyl acrylate, the α-proton (orange) disappears as product is formed and is exchanged for a deuterium in parallel. The blue and purple peaks change from a doublet to a singlet as product is formed, and the blue peak overlaps with 1 of 3 protons in the product. The three labelled protons in the product could not be distinguished and could hence correspond to peaks marked by any of the three colours (red, blue and green) in the spectrum.