Benzimidazole and Imidazole Derivatives

<p>Impurity Itraconazole EP Impurity A<br>Applications 2-(2-Butyl)-4-{4-[4-(4-methyloxy-phenyl)-piperazin-1-yl]-phenyl}-2,4-dihydro-[1,2,4]-triazol-3-one (Itraconazole EP Impurity A) is an intermediate of Itraconazole.<br></p>

<p>Applications Nitroguanidine is used in the prediction of heats of detonation of energetic compounds from their molecular structure. It is also used in the synthetic preparation of imidacloprid-d4 (I274992), which is a neonicotinoid.<br> E0<br>References Keshavarz, M.H., et al.: Propellant, Explosives, Pyrotechnics, 37, 93 (2012); Chauzat, M., et al.: Env. Entomol., 38, 514 (2009), Patial, A., et al.: Env. Ecol., 27, 320 (2009), Fernandez-Bayo, J., et al.: J. Agric., Food Chem., 57, 5435 (2009), Tomizawa, M., et al.: J. Med. Chem., 52, 3735 (2009), Chem. and Eng. News 90: 10 (2012)<br></p>

<p>Applications Isometronidazole-D4 is a labelled analogue of Isometronidazole (I821342). Isometronidazole is an impurity of Metronidazole (M338880), a chemotherapeutic agent that is used as a first line defense against Clostridium difficile (C.diff). Isometronidazole is also a hypoxic cell sensitizer in humans and mice.<br>References Hentschel, M. &amp; Schmidt, W.: Die Pharm., 47, 221 (1992); Musher, D., et al.: Clin. Inf. Dis., 40, 1586 (2005); Rosenkranz, H. &amp; Speck, W.: Biochem. Biophys. Res. Comm., 66, 520 (1975)<br></p>

<p>Applications 4,4'-(1-METHYLENE) BIS-BENZONITRILE (cas# 10466-37-2) is a useful research chemical.<br></p>

<p>Albendazole is an anti-helminthic drug that is structurally classified as a benzimidazole. It has been shown to be effective against a variety of helminths, including roundworms, pinworms, hookworms, and tapeworms. Albendazole impurity F is an analytical standard for the determination of albendazole in pharmaceutical products by HPLC. It also serves as a reference substance to establish the purity of drug products containing albendazole and its metabolites. Albendazole impurity F is not considered to be a metabolite of albendazole because it has been shown to be stable under acidic conditions and can be synthesized from other starting materials.</p>

<p>Scopine-2,2-dithienyl glycolate is a catalyst that belongs to the class of dithienyl glycolates. Scopine-2,2-dithienyl glycolate is used in the pharmaceutical industry as an average catalyst for reactions and can be used to recover dimethylbenzene. The method of detection for scopine-2,2-dithienyl glycolate is based on its ability to absorb light at a wavelength of 360 nm. The reaction solution must be monitored carefully during the synthetic process because it has been shown that it can react with water or air and form hydrogen sulfide gas. If this happens, the reaction solution will become cloudy or turbid. This product is a white crystalline solid that appears as tiny needles and has a melting point of 173 degrees Celsius (340 degrees Fahrenheit).</p>

<p>Ethyl (S)-1-phenyl-1,2,3,4-tetrahydro-2-isoquinolinecarboxylate is an analytical standard used to identify impurities in drug products. It is a metabolite of the drug product and has been shown to be safe for human consumption. The compound is a synthetic chemical that is not found naturally in the environment. CAS No. 180468-42-2</p>

<p>1-Phenyl-1,2,3,4-tetrahydro-isoquinoline is a synthetic compound which has been used as a lead compound for the development of drugs with dopamine β-hydroxylase inhibitory activity. In vitro studies have shown that 1-phenyl-1,2,3,4-tetrahydro-isoquinoline inhibits human serum dopamine β-hydroxylase and can be used to study the possible role of this enzyme in Parkinson's disease. This drug is racemized in the body and has been found to be effective against Parkinson's disease in rats. It is also an enantiomer that has industrial applications for the production of polyurethane foam insulation coatings.</p>

<p>2-Hydroxy-5-methylphenylbenzenepropanol is an aliphatic phenol that is used as a treatment for benzene poisoning. It is also used as a precursor to other compounds, such as the chlorides and alkylates of 2-hydroxy-5-methylphenylbenzenepropanol. This compound can be synthesized by reacting ethyl benzoylacetate with diisopropylamine in the presence of oxygen and chlorine gas. It is often immobilized using nutrients, l-tartaric acid, or cinnamic acid.</p>

<p>Donepezil benzyl bromide is a by-product of donepezil hydrochloride, which is an industrially important drug used to treat Alzheimer's disease. It has been shown to be more efficient than its hydrochloride form. Donepezil benzyl bromide is a crystalline substance that is insoluble in water and soluble in organic solvents such as acetone or ethanol. The compound can be purified through recrystallization from an appropriate solvent.</p>

<p>Carbamazepine is a drug that has been used to treat epileptic seizures and trigeminal neuralgia. Impurities in the drug are removed by using chromatographic methods, such as high-performance liquid chromatography (HPLC). The rotarod test is an animal model of motor coordination and balance that can be used to assess the effects of drugs on these functions. Carbamazepine impurities may cause depression and have an epileptic effect on animals. Chronic exposure to carbamazepine can lead to drug reactions and gene polymorphisms, which may alter the metabolism of the drug. Analytical methods for determining carbamazepine impurities include HPLC, gas chromatography mass spectrometry (GC-MS), and thin-layer chromatography (TLC).</p>

<p>Pantoprazole sulfone N-oxide is a prodrug that is converted to the active form pantoprazole in the stomach where it inhibits gastric acid secretion. Pantoprazole sulfone N-oxide has been shown to be genotoxic, and can cause polyvinyl chloride to degrade when stored together. Reconstituted solution of this drug should be used within 24 hours after reconstitution, as the chemical stability of this drug decreases rapidly. Validation studies have been conducted on different analytical methods for determining pantoprazole concentrations in reconstituted solutions, and these methods have been harmonized with those published by the United States Pharmacopeia (USP). The pump inhibitor activity of pantoprazole sulfone N-oxide has been demonstrated in dogs, and it is also useful for treating acid reflux disease in humans. Pantoprazole sulfone N-oxide is unstable at high temperatures (&gt;25°C), so should not be refrigerated or</p>

<p>Dehydrodeoxy donepezil is an analytical standard that is used in the manufacture of pharmaceuticals. It is a synthetic drug impurity, and its CAS number is 120013-45-8. Dehydrodeoxy donepezil can be found in the API impurity grade of various drugs, including those that are manufactured by Custom synthesis and natural synthesis. The pharmacopoeia states that dehydrodeoxy donepezil has a purity level of 98% or greater. This product can also be found as a metabolite in humans, with its half-life being approximately 40 minutes.</p>

<p>6-Methyl-4-phenyl-3,4-dihydro-1-benzopyran-2-one is an analog of the natural product zearalenone, which can be used as an acid catalyst for the synthesis of various pharmaceuticals. It has a linear range and is structurally similar to a number of other analogs. The chloride ion is involved in the optimization of the extraction parameters and can be replaced by other c1-4 alkyl groups. 6-Methyl-4-phenyl-3,4-dihydro-1 -benzopyran 2 one is typically prepared using a preparative high performance liquid chromatography technique that involves dehydration.</p>