On the Mechanism of Formation and the Synthesis of Pantoprazole Sodium Sesquihydrate-Related Compound E: A Phantom Chemical Entity

Abstract

A mechanism for the formation of pantoprazole related compound E (RC E) is proposed involving the formation of a radical cation in the pH range of 5–8. pH dependence of RC E is demonstrated, and the contribution of the difluoromethoxy group in stabilizing the C-6 free radical, a prerequisite to the formation of the dimer byproduct, is discussed. Also, the synthesis of pantoprazole RC E is reported using the benzidine rearrangement.

Efficient Synthesis of Potential Impurities in Levonadifloxacin (WCK 771)

“…The resulting solid was filtered, washed with water (575 mL), and dried at 60 °C for 6 h to obtain compound 21 as a lightbrown solid (150 g, 89.4% yield). 1 yl-6,7-dihydro-1-oxo-1H,5H-benzo[i,j]-quinolizine-2carboxylic acid (8). Part A: To a solution of compound 21 (120 g, 0.29 mol) in DMSO (240 mL) was added TEA (32.5 g, 0.32 mol) under stirring at 25 °C.…”

“…Impurity profile studies are thus necessary to certify the purity, quality, safety, and efficacy of the drug product during API development. Also, purification of an API is usually the most difficult step in its production and can be facilitated by suppressing the formation of impurities . Hence, it is very important to make available these impurities during drug development for their accurate quantification in drug substance and drug product.…”

“…Also, purification of an API is usually the most difficult step in its production and can be facilitated by suppressing the formation of impurities. 8 Hence, it is very important to make available these impurities during drug development for their accurate quantification in drug substance and drug product. Their reference standards are required in analytical method development, validation, and during batch release and stability studies of drug substance or product.…”