A convenient and practical synthesis of olmesartan medoxomil methyl ether

Development of efficient one-pot three-component assembly of trityl olmesartan medoxomil

We have elaborated a one-pot three-component assembly of trityl olmesartan medoxomil starting from commercially available ethyl 4-(2-hydroxypropan-2-yl)-2-propyl-1H-imidazole-5-carboxylate, 5-(4'-(bromomethyl)-[1,1'-biphenyl]-2-yl)-1-trityl-1H-tetrazole and 4-(chloromethyl)-5-methyl-1,3-dioxol-2-one intermediates. The developed and optimized one-pot process provides 72-75% yield of trityl olmesartan medoxomil over three steps, which represents in average ca. 90% yield per synthetic step, on a 300 g scale. The process is conducted in simple fashion and provides highly pure trityl olmesartan medoxomil (up to 97.5% by HPLC), which can be easily converted to olmesartan medoxomil that fully complies with all ICH requirements. Furthermore, the described process significantly improves the primary process to trityl olmesartan medoxomil by drastic reduction of required unit operations and application of single reaction solvent through the reaction sequence. Moreover, the amount of used organic solvents was notably reduced. The developed process has provided solid bases for industrial production of trityl olmesartan medoxomil.

The synthesis of [1-14 C]2-(1H-tetrazol-5-yl)acetic acid

Tetrazoles are a common heterocyclic functionality in many biologically active molecules. [1-¹⁴ C]2-(1H-Tetrazol-5-yl)acetic acid was required as an intermediate in the synthesis of a development candidate as part of a discovery phase program to complete metabolic profiling studies. [1-¹⁴ C]2-(1H-Tetrazol-5-yl)acetic acid was prepared in 4 steps overall and in 3 radiochemical steps from K¹⁴ CN in an overall 32% radiochemical yield.

Synthesis and Characterization of Process-Related Impurities of Antihypertensive Drug Olmesartan Medoxomil

Olmesartan medoxomil(1)is the latest angiotensin receptor antagonist approved by the FDA for the treatment of hypertension. During the process development of olmesartan medoxomil, three process-related impurities were observed along with the final API. These impurities were identified as isopropyl olmesartan (12), dimedoxomil olmesartan (19), dibiphenyl olmesartan (17). The present work describes the synthesis and characterization of all these three impurities.