A Convenient Regioselective Synthesis of 6-Amino-2-oxo-3,5-pyridinedicarbonitriles

2003 ◽  
Vol 58 (7) ◽  
pp. 678-685 ◽  
Author(s):  
Adel S. Girgis ◽  
Hanaa M. Hosni ◽  
I. S. Ahmed-Farag
Keyword(s):  
Acetic Anhydride ◽  
Single Crystal ◽  
Regioselective Synthesis ◽  
X Ray Diffraction ◽  
Basic Catalysis ◽  
X Ray

Reaction of cyanoacetohydrazones 3a,b with a variety of arylidenemalononitriles 5a - c under the effect of piperidine basic catalysis afforded exclusively the corresponding 6-amino-1,2-dihydro-1,4- disubstituted-2-oxo-3,5-pyridinedicarbonitriles 6a - f in high regioselectivity. A chemical confirmation for the proposed structure was achieved through the reaction of ylidenes 8 with malononitrile under basic conditions, which yielded the corresponding 6 accompanied with 3. Refluxing 3b in acetic anhydride gave 2-acetyl-3-cyanomethyl-4,5-dihydro-2H-benz[g]indazole (10) as the only isolable product. Single crystal X-ray diffraction of 6e and 10 add conclusive support for the established structures.

Heterocycles 21. Reaction of 2-phenyl-thiazol-4-carbaldehyde with 2-bromoacetophenone

2008 ◽  
Vol 59 (11) ◽  
Author(s):  
Valentin Zaharia ◽  
Anca Silvestru ◽  
Philippe Verite ◽  
Mircea Vlassa ◽  
Silvia Imre ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Infrared Spectroscopy ◽  
Acetic Anhydride ◽  
Single Crystal ◽  
Condensation Reaction ◽  
Spectroscopic Methods ◽  
X Ray Diffraction ◽  
Basic Catalysis ◽  
X Ray ◽  
Diffraction Structure

The condensation reaction of 2-phenyl-thiazol-4-carbaldehyde with 2-bromoacetophenone was performed in basic catalysis, resulting in a mixture of 2,3-epoxy-1-phenyl-3-(2-phenyl-thiazol-4-yl)-propan-1-one (1), 1-phenyl-3-(2-phenyl-thiazol-4-yl)-propane-1,2-dione (2) and 2-phenyl-4,5-bis-(2-phenyl-thiazol-4-yl)-3-hydroxy-furane (4). The isolated solids were structurally investigated by spectroscopic methods, i.e. infrared spectroscopy, mass spectrometry and NMR. In solution the dicarbonylic derivative 2 undergoes a tautomeric process, resulting in the enol 2-hydroxy-1-phenyl-3-(2-phenyl-thiazol-4-yl)-prop-2-en-1-one 3. Compounds 3 and 4 were transformed in the corresponding acetyl derivatives 5 and 6, respectively, by reacting them with acetic anhydride. For the furane 4 the single crystal X-ray diffraction structure was determined.

Simple Synthesis of Substituted 3-Hydroxyfuran-2(5H)-ones

Synthesis ◽  
2021 ◽  
Author(s):  
Natalya Yu. Lisovenko ◽  
Ekaterina R. Nasibullina ◽  
Svetlana S. Kharitonova ◽  
Olga A. Myshkina
Keyword(s):  
Single Crystal ◽  
Simple Synthesis ◽  
Regioselective Synthesis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Trichloromethyl Group ◽  
Subsequent Hydrolysis

AbstractA convenient and facile approach to functionalized 4-substituted 3,5-dihydroxy-5-(trichloromethyl)furan-2(5H)-ones was developed. This method is based on regioselective synthesis of novel furan-2,3-diones containing the trichloromethyl group and subsequent hydrolysis. The structures of compounds were unambiguously confirmed by single-crystal X-ray diffraction.

Electron Microscopy of Shock Loaded Polycrystalline Beryllium

1974 ◽  
Vol 32 ◽  
pp. 506-507 ◽  
Author(s):  
J. M. Galbraith ◽  
L. E. Murr ◽  
A. L. Stevens
Keyword(s):  
Electron Microscopy ◽  
Wave Propagation ◽  
Structural Change ◽  
Single Crystal ◽  
Diffraction Pattern ◽  
Shock Loading ◽  
Slip Systems ◽  
Compression Tests ◽  
X Ray Diffraction ◽  
X Ray

Uniaxial compression tests and hydrostatic tests at pressures up to 27 kbars have been performed to determine operating slip systems in single crystal and polycrystal1ine beryllium. A recent study has been made of wave propagation in single crystal beryllium by shock loading to selectively activate various slip systems, and this has been followed by a study of wave propagation and spallation in textured, polycrystal1ine beryllium. An alteration in the X-ray diffraction pattern has been noted after shock loading, but this alteration has not yet been correlated with any structural change occurring during shock loading of polycrystal1ine beryllium.This study is being conducted in an effort to characterize the effects of shock loading on textured, polycrystal1ine beryllium. Samples were fabricated from a billet of Kawecki-Berylco hot pressed HP-10 beryllium.

Crystal structure of an inclusion complex between chiral monoaza-15-crown-5 and S(–)-1-phenyl-ethyl ammonium percholorate

2003 ◽  
Vol 218 (5) ◽  
Author(s):  
Süheyla Özbey ◽  
F. B. Kaynak ◽  
M. Toğrul ◽  
N. Demirel ◽  
H. Hoşgören
Keyword(s):  
Crystal Structure ◽  
Inclusion Complex ◽  
Single Crystal ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
New Type

AbstractA new type of inclusion complex, S(–)-1 phenyl ethyl ammonium percholorate complex of R-(–)-2-ethyl - N - benzyl - 4, 7, 10, 13 - tetraoxa -1- azacyclopentadecane, has been prepared and studied by NMR, IR and single crystal X-ray diffraction techniques. The compound crystallizes in space group

An unusual reaction of a bridged triterpenoid α-diketone with acetic anhydride

1991 ◽  
Vol 56 (12) ◽  
pp. 2917-2935 ◽  
Author(s):  
Eva Klinotová ◽  
Václav Křeček ◽  
Jiří Klinot ◽  
Miloš Buděšínský ◽  
Jaroslav Podlaha ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Nmr Spectroscopy ◽  
Acetic Anhydride ◽  
Spectral Methods ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mild Conditions ◽  
Condensation Products ◽  
Unsaturated Lactones ◽  
C Nmr

3β-Acetoxy-21,22-dioxo-18α,19βH-ursan-28,20β-olide (IIIa) reacts with acetic anhydride in pyridine under very mild conditions affording β-lactone IVa and γ-lactones Va and VIIa as condensation products. On reaction with pyridine, lactones Va and VIIa undergo elimination of acetic acid to give unsaturated lactones VIIIa and IXa, respectively. Similarly, the condensation of 20β,28-epoxy-21,22-dioxo-18α,19βH-ursan-3β-yl acetate (IIIb) with acetic anhydride leads to β-lactone IVb and γ-lactone Vb; the latter on heating with pyridine affords unsaturated lactone VIIIb and 21-methylene-22-ketone Xb. The structure of the obtained compounds was derived using spectral methods, particularly 1H and 13C NMR spectroscopy; structure of lactone IVa was confirmed by X-ray diffraction.

Unusual Rearrangement of Naphthalene in the Synthesis of a Novel B8-B8-Bridged Derivative in the [(1,2-C2B9H11)2-3-Co]- Series. X-Ray Structure and 11B NMR Spectra of [8,8'-μ-(CH2-C9H6)-(1,2-C2B9H10)2-3-Co]- (CH3)4N+

1997 ◽  
Vol 62 (5) ◽  
pp. 746-751 ◽  
Author(s):  
Andreas Franken ◽  
Jaromír Plešek ◽  
Christiane Nachtigal
Keyword(s):  
Nmr Spectroscopy ◽  
Single Crystal ◽  
Nucleophilic Substitution ◽  
Nmr Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Unusual Rearrangement ◽  
Multinuclear Nmr Spectroscopy ◽  
11B Nmr ◽  
Isolated Compound

On treatment of the [(1,2-C2B9H11)2Co]- ion with naphthalene in presence of AlCl3 a remarkably bridged [8,8'-μ-(CH2-C9H6)-(1,2-C2B9H10)2-3-Co]- ion is obtained as a single isolated compound. The triatomic -CH2-C9H6- bridge is derived from the rearranged naphthalene nucleus. The mechanism of this reaction is obscure but it does resemble the "Electrophile-Induced Nucleophilic Substitution" reported earlier. The structure of the compound was established by multinuclear NMR spectroscopy and by single crystal X-ray diffraction.

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