On steroids. IV. A new synthesis of Δ5-3-hydroxyetienic acid from 17-ketoandrostene-(5)

1953 ◽  
Vol 18 (3) ◽  
pp. 407-412
Author(s):  
F. Šorm ◽  
V. Černý
Keyword(s):  
New Synthesis

Tandem Carbon-Radical Peroxidation−Addition to Carbonyl Groups Reaction. A New Synthesis of Steroidal β-Peroxy Lactones

1996 ◽  
Vol 61 (26) ◽  
pp. 9635-9635
Author(s):  
Alicia Boto ◽  
Rosendo Hernández ◽  
Ernesto Suárez ◽  
Carmen Betancor ◽  
María S. Rodríguez
Keyword(s):  
Carbonyl Groups ◽  
New Synthesis

1,3-Selenaphospholes: A New Synthesis from 1,2,3-Selenadiazoles and Kinetically Stabilized Phosphaalkynes1

Synlett ◽  
1991 ◽  
Vol 1991 (04) ◽  
pp. 356-358 ◽  
Author(s):  
Bernd Burkhart ◽  
Steffen Krill ◽  
Yoshinori Okano ◽  
Wataru Ando ◽  
Manfred Regitz
Keyword(s):  
New Synthesis

A New Synthesis and Analysis of Silica Nanowire Periodically Wrapped by Nano-spheres

2016 ◽  
Vol 31 (5) ◽  
pp. 523
Author(s):  
MA Hong-Bing ◽  
BAI Hua ◽  
XUE Chen ◽  
TAO Peng-Fei ◽  
XU Qun-Feng ◽  
...  
Keyword(s):  
New Synthesis

New Synthesis of Isoindolo[2,1–b]isoquinolines. Preparation and Aqueous Bioavailability of its Silica Nanoparticles Hybrid System

2015 ◽  
Vol 19 (13) ◽  
pp. 1292-1300 ◽  
Author(s):  
Amelia Diaz ◽  
J. Manuel Lopez–Romero ◽  
Rafael Contreras-Caceres ◽  
Manuel Algarra ◽  
Rodrigo Rico ◽  
...  
Keyword(s):  
Silica Nanoparticles ◽  
Hybrid System ◽  
New Synthesis

A Short Synthesis of the Plant Alkaloid 4-Methyl-2,6-naphthyridine

2019 ◽  
Vol 16 (12) ◽  
pp. 931-934 ◽  
Author(s):  
Alexandra Kamlah ◽  
Franz Bracher
Keyword(s):  
Pyridine Ring ◽  
Cross Coupling ◽  
Antirrhinum Majus ◽  
New Synthesis ◽  
Short Synthesis ◽  
Regioselective Oxidation ◽  
Key Steps

: A new synthesis of the 2,6-naphthyridine alkaloid 4-methyl-2,6-naphthyridine from Antirrhinum majus has been developed. Key steps are a regioselective oxidation of 3-bromo-4,5- dimethylpyridine to the corresponding 4-formyl derivative, and the annulation of the second pyridine ring by Suzuki-Miyaura cross-coupling using (E)-2-ethoxyvinylboronic acid pinacol ester as a masked acetaldehyde equivalent. This protocol gives the alkaloid in four steps starting from commercially available 3,4-dimethylpyridine in 15% overall yield. This annulation protocol should be useful for the synthesis of other condensed pyridines as well.

Synthesis, Analytical Characterization and Spectroscopic Investigation of Chloramphenicol Impurity A for the Quality Control of Chloramphenicol and its Formulation as Per International Compendium

2020 ◽  
Vol 17 (5) ◽  
pp. 382-388
Author(s):  
Aparna Wadhwa ◽  
Faraat Ali ◽  
Sana Parveen ◽  
Robin Kumar ◽  
Gyanendra N. Singh
Keyword(s):  
Quality Control ◽  
Synthesis Method ◽  
Analytical Techniques ◽  
International Markets ◽  
Therapeutic Effects ◽  
Reference Standard ◽  
Working Standard ◽  
Prior Art ◽  
New Synthesis ◽  
Synthetic Procedure

Objective: The main aim of the present work is to synthesize chloramphenicol impurity A (CLRMIMP- A) in the purest form and its subsequent characterization by using a panel of sophisticated analytical techniques (LC-MS, DSC, TGA, NMR, FTIR, HPLC, and CHNS) to provide as a reference standard mentioned in most of the international compendiums, including IP, BP, USP, and EP. The present synthetic procedure has not been disclosed anywhere in the prior art. Methods: A simple, cheaper, and new synthesis method was described for the preparation of CLRM-IMP-A. It was synthesized and characterized by FTIR, DSC, TGA, NMR (1H and 13C), LC-MS, CHNS, and HPLC. Results: CLRM-IMP-A present in drugs and dosage form can alter the therapeutic effects and adverse reaction of a drug considerably, it is mandatory to have a precise method for the estimation of impurities to safeguard the public health. Under these circumstances, the presence of CLRM-IMP-A in chloramphenicol (CLRM) requires strict quality control to satisfy the specified regulatory limit. The synthetic impurity obtained was in the pure form to provide a certified reference standard or working standard to stakeholders with defined potency. Conclusion: The present research describes a novel technique for the synthesis of pharmacopoeial impurity, which can help in checking/controlling the quality of the CLRM in the international markets.

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