نتایج جستجو برای: 4h pyran

تعداد نتایج: 7801  

2009
Hossein Rahmani Hooshang Pirelahi Seik Weng Ng

The asymmetric unit of the title compound, C(25)H(22)OS, comprises two similar 4-(4-methoxy-phen-yl)-4-methyl-2,6-diphenyl-4H-thio-pyran mol-ecules. In each, the six-membered thio-pyran ring adopts a planar conformation (r.m.s. deviation of 0.041Å for the ring in one mol-ecule and 0.008 Å in the other). The methoxy-phenyl substituent is in a pseudo-axial position. The crystal studied is an inve...

2014
David P. Martin Patrick G. Blachly Amy R. Marts Tessa M. Woodruff César A. F. de Oliveira J. Andrew McCammon David L. Tierney Seth M. Cohen

The binding of three closely related chelators: 5-hydroxy-2-methyl-4H-pyran-4-thione (allothiomaltol, ATM), 3-hydroxy-2-methyl-4H-pyran-4-thione (thiomaltol, TM), and 3-hydroxy-4H-pyran-4-thione (thiopyromeconic acid, TPMA) to the active site of human carbonic anhydrase II (hCAII) has been investigated. Two of these ligands display a monodentate mode of coordination to the active site Zn(2+) io...

Journal: :Analytical chemistry 1972
J P Hardy S L Kerrin

greater than the response of similarly treated blanks at the 5-gg level and 400 times greater than the response of methanol to flame ionization detection (1 ,5 ) . The compound in which the methanol is to be determined, must be somewhat water soluble. Complete dissolution of the sample weight taken in the 1-ml water-urea mixture used is necessary to free the methanol for subsequent reaction. Ac...

2016
Surya Narayana Maddila Suresh Maddila Werner E. van Zyl Sreekantha B. Jonnalagadda

We designed a ceria-vanadia/silica (Ce-V/SiO2) heterogeneous catalyst and used it for the green and efficient synthesis of 2-amino-3-cyano-4H-pyran derivatives. The green reaction was a multicomponent one-pot condensation of 5,5-dimethylcyclohexane-1,3-dione, aromatic aldehyde, and malononitrile in an eco-compatible solvent (ethanol). The catalyst was synthesized and fully characterized by powd...

2012
Shaaban K. Mohamed Mehmet Akkurt Muhammad N. Tahir Antar A. Abdelhamid Mustafa R. Albayati

The 4H-pyran ring of the title compound, C(17)H(16)N(2)O(2), is nearly planar [maximum deviation = 0.077 (2) Å] and the cyclo-hexene ring adopts a flattened chair conformation [puckering parameters: Q(T) = 0.435 (2) Å, θ = 122.0 (3)° and ϕ = 53.5 (3)°]. The 4H-pyran ring is almost perpendicular to the benzene ring [dihedral angle = 87.23 (8)°] and is almost coplanar with the mean plane of the c...

2012
Shaaban K. Mohamed Mehmet Akkurt Muhammad N. Tahir Antar A. Abdelhamid Mustafa R. Albayati

In the title compound, C(18)H(17)ClN(2)O(2)·C(3)H(6)O, the 4H-pyran ring is nearly planar [maximum deviation = -0.108 (1) Å] and the cyclo-hexene ring is puckered [puckering parameters Q(T) = 0.4596 (17) Å, θ = 55.9 (2)° and ϕ = 226.5 (3)°]. The 4H-pyran ring is approximately perpendicular to the benzene ring [dihedral angle = 84.35 (7)°] and is almost coplanar with the mean plane of the cyclo-...

Journal: :iranian chemical communication 2015
amit s. waghmare shivaji s. pandit

the three components one pot synthesis of 2-amino-4h-benzo-[b] -pyran derivatives were obtained in good to excellent yields within short reaction time by condensing dimedone, aldehydes and malanonitrile or ethylcyanoacetate using a catalytic amount of (diacetoxyiodo)benzene as hypervalent iodine in aqueous ethanol under reflux conditions have been discussed. this aqua mediated knoevenagel-cyclo...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 1996
aziz shahrisa salar hemmati

synthesis of 4-(n,n- dimethylamino)-3-aryl-3-butene-2-one, ethyl-5-aryl-4-oxo-4h-pyran-2-carboxylate, ethyl-5-aryl-4-pyridones-2-carboxylate and 5-aryl-3-cyano-5-methyl-2-pyridones (aryl=3-thienyl, 2-furyl) are described.

Water is a versatile solvent in many ways, and in this sense performing organic reactions in this medium is now of great interest. The one-pot reaction of ethyl acetoacetate or benzyl acetoacetate, with benzaldehydes and malononitrile to provide some novel 6-amino-4-aryl-5-cyano-2-methyl-4H-pyran-3-carboxylates has been performed over nano MgO with high performance in water as a green solvent a...

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