نتایج جستجو برای: ddq

تعداد نتایج: 283  

Journal: :Chemical & pharmaceutical bulletin 2000
M Murase K Watanabe T Yoshida S Tobinaga

The nucleophilic addition reaction of N-tosyl-4-oxo-4,5,6,7-tetrahydroindole (12) with the lithium salt of 1-methoxyindole (5), followed by dehydration with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) gave the derivative of 2,4'-bi-1H-indole (9) which provides a new concise synthetic method of an indole pigment of the slime mould, arcyriacyanin A. The compound was first demonstrated here to...

Journal: :Molecules 2011
Nilesh Zaware Matthew G Laporte Ramy Farid Lei Liu Peter Wipf Paul E Floreancig

Eighteen (2RS,6RS)-2-(4-methoxyphenyl)-6-(substituted ethyl)dihydro-2H-pyran-4(3H)ones were synthesized via a DDQ-mediated oxidative carbon-hydrogen bond activation reaction. Fourteen of these tetrahydropyrans were substituted with triazoles readily assembled via azide-alkyne click-chemistry reactions. Examples of a linked benzotriazole and pyrazole motif were also prepared. To complement the s...

Journal: :Decision Support Systems 2008
Michael J. Davern Ravi Mantena Edward A. Stohr

Human decision making is error-prone and often subject to biases. Important information cues are misweighted and feedback delays hamper learning. Experimentally, task information has been shown to be valuable in improving decision making. However, such information is rarely available. Generalizing from lab-based approaches, we present a new field methodology for the “Diagnosis of Decision Quali...

2012
M. RAMESH KUMAR T. SREENIVASULU REDDY K. PRABHAVATHI

A simple, sensitive spectrophotometric method was developed for the determination of rabeprazole in pure form and for pharmaceutical formulations. In this method 2,3-dichloro-5, 6-dicyano-p-benzoquinone (DDQ) was utilized for determination of rabeprazole forming charge transfer complex with maximum absorbance at λmax 460 nm. Variables affecting the reaction were studied and optimized. Beer’s la...

Journal: :Analytical sciences : the international journal of the Japan Society for Analytical Chemistry 2004
Nafisur Rahman Nadeem Ahmad Khan Syed Najmul Hejaz Azmi

Two simple, sensitive and economical spectrophotometric methods have been developed for the determination of amiodarone hydrochloride in pure form and commercial dosage form. These methods (A and B) are based on the reaction of amiodarone base as n-electron donor with p-chloranilic acid and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) as pi-acceptors to give highly colored complex species wh...

2010
Moamen S. Refat Gehad G. Mohamed Ahmed Fathi

Spectrophotometric micro determination of allopurinol (ALP) via charge-transfer formation is described. This includes the utility of some π-acceptors such as 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) and 3,6-dichloro-2,5-dihydroxy-p-benzoquinone (p-CLA) for estimation of ALP drug (act as è-donor). These reactions are applied for determination of ALP in its pharmaceutical preparations coming...

Journal: :Organic & biomolecular chemistry 2014
Xiaoqing Xin Xu Liu Dingyuan Zhang Rui Zhang Yongjiu Liang Fushe Han Dewen Dong

An efficient and divergent one-pot synthesis of 2,3-dihydro-1H-pyrroles, 3-alkyl-1H-pyrroles and 3-alkenyl-1H-pyrroles from readily accessible 2,4-pentadienenitriles with isocyanide based on reaction condition selection has been described. The reaction of 2,4-pentadienenitriles with ethyl isocyanoacetate undergoes a formal [2 + 3] annulation either to generate 2,3-dihydro-1H-pyrroles in the pre...

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