4-Methylindole

clear yellow to brown liquid after melting

4-methylindole (4-MID), was selected as a potential liquid organic hydrogen carrier (LOHC) because of its theoretical hydrogen storage density of 5.76 wt%, a melting point of 5 °C and a boiling point of 267 °C [1]. 4-Methylindole serves as a lead activator of the aryl hydrocarbon receptor (AhR), facilitating investigations into its effect on AhR nuclear translocation in LS180 cells[2]. Hydrogenation of 4-methylindole yields octahydro-4-methylindole (8H-4-MID) after solvent distillation[1].

[1] Zhang, X., Wang, H., Wang, X., Wang, N., & Wu, X. (2025). Study of catalytic hydrogenation dehydrogenation on an alternative LOHC: 4-methylindole. International Journal of Hydrogen Energy, 109, Pages 1437-1443. https://doi.org/10.1016/j.ijhydene.2025.01.067
[2] Stepankova, M., Bartonkova, I., Jiskrova, E., Vrzal, R., Mani, S., Kortagere, S., & Dvorak, Z. (2018). Methylindoles and Methoxyindoles are Agonists and Antagonists of Human Aryl Hydrocarbon Receptor. Molecular Pharmacology, 93 6, 631–644. https://doi.org/10.1124/mol.118.112151