107512-34-5Relevant articles and documents
Purification synthesis method of 2-methyl-3-methoxy-4-chloropyridine
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Paragraph 0029-0031; 0032-0035; 0036-0041; 0042-0048, (2020/12/08)
The invention discloses a purification synthesis method of 2-methyl-3-methoxy-4-chloropyridine. The method comprises the following steps: carrying out low-temperature crystallization purification on raw material 2-methyl-3-methoxy-4H-pyridine to remove organic impurities in raw material B2, thereby reducing the content of side reaction substances in the chlorination reaction; and side reactions such as decomposition and degradation of a reaction product are reduced through an improved mode of rapidly distilling a chlorination liquid and an extraction liquid, so that the yield is increased, theconsumption and three wastes are reduced, and a remarkable effect is achieved. The improved process is convenient to operate, mild in reaction condition, safe, reliable, high in product yield and lowin cost.
Preparation method of 2-methyl-3-methoxyl-4-chloropyridine
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Paragraph 0025-0059, (2018/05/16)
The invention discloses a preparation method of 2-methyl-3-methoxyl-4-chloropyridine. The preparation method comprises the following steps: adding 10 to 15 kg of 2-methyl-3-methoxyl-4H-pyridine into 50 to 75 kg of dichloroethane, and heating to dissolve the mixture; slowly adding 12 to 18 kg of phosphorus oxychloride into the solution under stirring; then performing heat preservation at 80 to 85 DEG C for 10 to 12 hours; performing reduced pressure distillation to recycle dichloroethane, cooling the material solution obtained by the reduced pressure distillation to 18 to 22 DEG C, and slowly adding the material solution into iced water for uniform stirring for hydrolysis; cooling the hydrolyzed material solution to 0 to 10 DEG C, adding an alkaline solution to adjust the pH of the materialsolution to 7 to 9, pouring the solution into a separating funnel for stewing for 1 to 2 hours, then collecting a lower-layer oily matter, extracting upper-layer liquid with an extractant, putting the extracted liquid into the collected oily matter, adding anhydrous sodium sulfate, performing drying and suction filtration, and performing reduced pressure evaporation to remove the extractant, thusobtaining the 2-methyl-3-methoxyl-4-chloropyridine. The preparation method is mild in reaction condition, convenient in technological operation, safe, reliable, high in product yield and low in cost.
Synthesis of a DOTA (Gd3+)-conjugate of proton-pump inhibitor pantoprazole for gastric wall imaging studies
Maharvi, Ghulam M.,Bharucha, Adil E.,Fauq, Abdul H.
supporting information, p. 2808 - 2811 (2013/06/27)
Magnetic resonance imaging (MRI) is used to evaluate gastrointestinal (GI) structure and functions in humans. Despite filling the viscus lumen with a contrast agent, visualization of the viscus wall is limited. To overcome this limitation, we de novo synthesized a conjugate that covalently combines a Gd-based MRI contrast agent, encaged with a chelating agent (DOTA), with pantoprazole, which is a widely used proton pump inhibitor that binds to proton pumps in the stomach and colon. The DOTA linkage was installed at a mechanism-based strategic location in the pantoprazole molecule to minimize a possible negative effect of the structural modification on the drug. It is anticipated that by defining the wall of the stomach and colon, this compound will facilitate functional MRI of the GI tract in humans.
