72830-08-1Relevant articles and documents
A pantoprazole intermediate 2 - chloromethyl - 3, 4 - dimethoxy pyridine hydrochloride preparation method
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, (2018/09/08)
The invention belongs to the technical field of medicine, and particularly relates to a preparation method of a pantoprazole intermediate 2-chloromethyl-3,4-dimethoxy pyridine hydrochloride. The preparation method comprises the following steps: using 3-hydroxyl-2-methyl-4-pyrone as a starting raw material, and then only performing five-step reaction to obtain the pantoprazole intermediate 2-chloromethyl-3,4-dimethoxy pyridine hydrochloride. The preparation method reduces the reaction steps, shortens the reaction cycle, improves the working efficiency, and increases the yield coefficient.
Slow, spontaneous degradation of lansoprazole, omeprazole and pantoprazole tablets: Isolation and structural characterization of the toxic antioxidants 3H-benzimidazole-2-thiones
Rajab,Touma,Rudler,Afonso,Seuleiman
, p. 749 - 754 (2013/10/08)
The spontaneous degradation of lansoprazole, omeprazole and pantoprazole tablets upon long-term and forced storage conditions was determined by high performance liquid chromatography (HPLC). The more abundant products could be isolated by liquid chromatography and their molecular weights determined by Mass Spectrometry (MS). Their structures, established according to their spectroscopic data, were compared to those of either the literature or of authentic samples. Thus lansoprazole led mainly to a mixture of 3H-benzimidazole-2-thione (2a) and 3H-benzimidazole-2-one (2c), omeprazole mainly to a mixture of 5-methoxy-3H-benzimidazole-2-thione (1a) and 2-hydroxymethyl-3, 5-dimethyl- 4-methoxypyridine (1b), and pantoprazole, to 5-difluoromethoxy-3H-benzimidazole-2-thione (3a) and 2-hydroxymethyl-3, 4-dimethoxypyridine (3b). Although some of the degradation products had already been observed under different conditions, the detection of benzimidazole-2- thiones is unprecedented and their involvement as possible physiological, yet toxic antioxidants must be emphasized. Plausible, unified mechanisms for the formation of the different degradation products observed herein and in previous papers from the literature are suggested.
Structure-activity relationship of omeprazole and analogues as Helicobacter pylori urease inhibitors
Kuhler,Fryklund,Bergman,Weilitz,Lee,Larsson
, p. 4906 - 4916 (2007/10/03)
Helicobacter pylori urease belongs to a family of highly conserved urea- hydrolyzing enzymes. A common feature of these enzymes is the presence of two Lewis acid nickel ions and a reactive cysteine residue in the active site. The H+/K+-ATPase inhibitor omeprazole is a prodrug of a sulfenamide which covalently modifies cysteine residues on the luminal side of the H+/K+- ATPase of gastric parietal cells. Omeprazole and eight analogues were selected based on their chemical, electronic, and kinetic properties, and each was incubated with viable H. pylori in phosphate-buffered saline at pH 7.4 for 30 min, after which 100 mM urea was added and the amount of ammonia formed analyzed after a further 10 min. Inhibition between 0% and 100% at a 0.1 mM concentration was observed for the different analogues and could be expressed as a function of the pK(a)-value of the pyridine, the pK(a)-value of the benzimidazole, the overall lipophilicity, and, most importantly, the rate of sulfenamide formation, in a quantitative structure-activity relationship. The inhibition was potentiated by a lower pH (favoring the formation of the sulfenamide) but abolished in the presence of β- mercaptoethanol (a scavenger of the sulfenamide). Structural analogues incapable of yielding the sulfenamide did not inhibit ammonia production. Treatment of Helicobacter felis-infected mice with 230 μmol/kg flurofamide b.i.d. for 4 weeks, known to potently inhibit urease activity in vivo, as a means of eradicating the infection, was tested and compared with the effect of 125 μmol/kg omeprazole b.i.d. for 4 weeks. Neither treatment proved efficacious.
