New Synthesis of Azulene
Heinz Langhals presents a new way to synthesize azulene.
A Convenient Synthesis of Azulene: H. Langhals, M. Eberspächer
Synthesis 2018, DOI: 10.1055/s-0036-1591906
Azulene is a bicyclic hydrocarbon characterized by a distinctive deep blue color. Its hydrophobicity renders it an ideal dye for staining non-hydrophilic materials which are otherwise difficult to stain, such as perfluorinated hydrocarbons, greasy polymers and silicon oil. The group of Professor Heinz Langhals (Ludwig-Maximilians-Universität Munich, Germany) has recently reported a new, convenient and scalable entry to azulene, using pyridine and 2,4-dinitro-chlorobenzene as starting materials.