Synthesis of isotopically labelled 2‐isopropylthioxanthone from 2,2′‐dithiosalicylic acid and deuterium cumene

Two efficient synthetic routes of stable deuterium labelled 2-isopropylthioxanthone were presented with 98.1% and 98.8% isotopic abundance in acceptable yields and excellent chemical purities. Their structures and the isotope-abundance were confirmed according to proton nuclear magnetic resonance and liquid chromatography-mass spectrometry.