A highly efficient continuous synthesis has been developed for telmisartan, the active ingredient in the antihypertensive drug, Micardis. This synthetic route employs a convergent strategy that requires no intermediate purifications or solvent exchanges. The key step in the reaction scheme is a Suzuki cross-coupling reaction between two functionalized benzimidazoles that is catalyzed by a solid-supported Pd catalyst. This flow-based approach utilizes a tubular reactor system coupled with a plug flow packed bed cartridge unit that produces telmisartan in an 81% isolated yield.
Lim, S. S.; Vos, T.; Flaxman, A. D.; Danaei, G.; Shibuya, K.; Adair-Rohani, H.et al. Lancet2012, 380, 2224–2260.
Lim, S. S.; Vos, T.; Flaxman, A. D.; Danaei, G.; Shibuya, K.; Adair-Rohani, H.et al. Lancet2012, 380, 2224–2260.)| false