scholarly journals Combining Two-Dimensional Diffusion-Ordered Nuclear Magnetic Resonance Spectroscopy, Imaging Desorption Electrospray Ionization Mass Spectrometry, and Direct Analysis in Real-Time Mass Spectrometry for the Integral Investigation of Counterfeit Pharmaceuticals

2009 ◽  
Vol 81 (12) ◽  
pp. 4803-4812 ◽  
Author(s):  
Leonard Nyadong ◽  
Glenn A. Harris ◽  
Stéphane Balayssac ◽  
Asiri S. Galhena ◽  
Myriam Malet-Martino ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Desorption Electrospray Ionization ◽  
Direct Analysis ◽  
Resonance Spectroscopy ◽  
Ionization Mass ◽  
Two Dimensional ◽  
Dimensional Diffusion ◽  
Magnetic Resonance Spectroscopy Imaging ◽  
Counterfeit Pharmaceuticals

scholarly journals A new tetracyclic diterpenoid from the seeds of Euphorbia lathyris

2020 ◽  
Vol 44 (5-6) ◽  
pp. 322-325
Author(s):  
Lie-Feng Ma ◽  
Yue Zhang ◽  
Xuan Zhang ◽  
Meng-Jia Chen ◽  
Zha-Jun Zhan ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
High Resolution ◽  
Spectroscopic Data ◽  
Resonance Spectroscopy ◽  
Ionization Mass ◽  
Two Dimensional ◽  
Detailed Interpretation ◽  
A Minor ◽  
Euphorbia Lathyris

Eupholathone, a minor diterpenoid with an unusual tetracyclic skeleton, was obtained from the seeds of Euphorbia lathyris, along with two known lathyrane diterpenoids, euphorbia factors L2 and L3. The structure of eupholathone was elucidated by detailed interpretation of its spectroscopic data, especially two-dimensional nuclear magnetic resonance spectroscopy and high-resolution electrospray ionization mass spectrometry.

scholarly journals A practical synthesis of 3-chloro-2,4-difluoro-5-hydroxybenzoic acid

2020 ◽  
pp. 174751982093225
Author(s):  
Mingguang Zhang ◽  
Zhongbao Bi ◽  
Yunyun Wang ◽  
Yuxun Zhao ◽  
Yang Yang ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Resonance Spectroscopy ◽  
Ionization Mass ◽  
Hydroxybenzoic Acid ◽  
Reaction Conditions ◽  
Reduction Of No ◽  
Synthetic Strategy ◽  
Practical Synthesis ◽  
Quinolinecarboxylic Acid

A new and practical synthesis of 3-chloro-2,4-difluoro-5-hydroxybenzoic acid, a key intermediate for preparing antimicrobial 3-quinolinecarboxylic acid drugs, is synthesized from 2,4-difluoro-3-chlororobenzoic acid. The protocol involves nitration, esterification, reduction of NO2, diazotization, and hydrolysis with a 70% overall yield. The structures of the synthesized compounds are determined by infrared spectroscopy, nuclear magnetic resonance spectroscopy, and high-resolution electrospray ionization mass spectrometry. The advantages of this developed synthetic strategy include an improved overall yield and readily controllable reaction conditions.

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