نتایج جستجو برای: Hantzsch

تعداد نتایج: 330  

Journal: :Clinical chemistry 1973
L B Foster R T Dunn

We describe a modified method for determining triglycerides in serum, in which alumina is used to adsorb interfering substances, and the glycerol content of triglycerides is determined colorimetrically. In contrast to all previous Hantzsch condensation procedures in which periodate and acetylacetone are used, the working periodate and the working acetylacetone reagents are stable for at least s...

2005
C. Hak C. Ordóñez A. S. H. Prévôt W. Junkermann

Results from an intercomparison of several currently used in-situ techniques for the measurement of atmospheric formaldehyde (CH2O) are presented. The measurements were carried out at Bresso, an urban site in the periphery of Milan (Italy) as part of the FORMAT-I field campaign. Eight instruments were employed by six independent research groups using four different techniques: Differential Opti...

Journal: :Advanced pharmaceutical bulletin 2011
Javid Shahbazi Mojarrad Zahra Zamani Hossein Nazemiyeh Saeed Ghasemi Davoud Asgari

INTRODUCTION We report the synthesis of novel 1,4-dihydropyridine derivatives containing biphenyl-2'-tetrazole moieties. We hypothesized that merging the key structural elements present in an AT1 receptor antagonist with key structural elements in 1,4-dihydropyridine calcium channel blockers would yield novel analogs with potential dual activity for both receptors. This strategy led to the desi...

2014
J. Kaiser X. Li R. Tillmann I. Acir F. Holland F. Rohrer R. Wegener F. N. Keutsch

Two gas-phase formaldehyde (HCHO) measurement techniques, a modified commercial wet-chemical instrument based on Hantzsch fluorimetry and a custombuilt instrument based on fiber laser-induced fluorescence (FILIF), were deployed at the atmospheric simulation chamber SAPHIR (Simulation of Atmospheric PHotochemistry In a large Reaction Chamber) to compare the instruments’ performances under a rang...

Journal: :Molecules 2007
Mirela Filipan-Litvić Mladen Litvić Ivica Cepanec Vladimir Vinković

Hantzsch condensation of two equivalents of methyl-3-aminocrotonate with (m- and p)-methoxybenzaldehyde afforded the expected products 2,6-dimethyl-3,5-dimethoxycarbonyl-4-(m-methoxyphenyl)-1,4-dihydropyridine and 2,6-dimethyl-3,5-dimethoxycarbonyl-4-(p-methoxyphenyl)-1,4-dihydropyridine, whereas o-methoxy-benzaldehyde produced mainly 1-amino-2-methoxycarbonyl-3,5-bis(o-methoxy-phenyl)-4-oxa-cy...

2010
Jun Che Yulin Lam

A polymer-supported Hantzsch 1,4-dihydropyridine ester was observed to be a useful selective reducing agent for the reduction of ketimines and electron-withdrawing conjugated olefins. The rate of the reduction of electron-withdrawing conjugated olefins is dependent on the nature of the conjugated substituents and could be enhanced by microwave irradiation. The reduction of (Z)-a-cyano-bbromomet...

2013
Mark C Bagley Vincenzo Fusillo Robert L Jenkins M Caterina Lubinu Christopher Mason

The Bohlmann-Rahtz pyridine synthesis and the Hantzsch dihydropyridine synthesis can be carried out in a microwave flow reactor or using a conductive heating flow platform for the continuous processing of material. In the Bohlmann-Rahtz reaction, the use of a Brønsted acid catalyst allows Michael addition and cyclodehydration to be carried out in a single step without isolation of intermediates...

Journal: :Molecules 2007
Saeed Dehghanpour Majid M Heravi Fatemeh Derikvand

A variety of Hantzsch 1,4-dihydropyridines were oxidized to their corresponding pyridines in high yields in the presence of Cu(C22H22N2O2) in refluxing acetic acid.

Journal: :Organic & biomolecular chemistry 2005
Ze Zhang Jie Gao Jing-Jing Xia Guan-Wu Wang

Under mechanical milling conditions, direct reductive benzylizations of malononitrile and 4-methylaniline by aromatic aldehydes were achieved using a Hantzsch 1,4-dihydropyridine as the reductant.

2013
Jérémy Stemper Kévin Isaac Julien Pastor Gilles Frison Pascal Retailleau Arnaud Voituriez Angela Marinetti Jean-François Betzer

This work deals with the development of a new family of planar chiral phosphoric acids, based on a ferrocenophane/paracyclophane scaffold. The synthetic approach has been improved by taking advantage of a chiral phosphorylating agent to access enantiomerically enriched acids via diastereomers separation. These phosphoric acids have been used as catalysts for the enantioselective H-transfer redu...

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