N,N′-Dicyano-p-acepleiadylenequinonediimine and Its 1,2-Dibromo Derivative: New DCNQI Type Acceptors and Their Conducting Complexes

2002 ◽  
Vol 31 (10) ◽  
pp. 1004-1005 ◽  
Author(s):  
Ohki Sato ◽  
Yuji Okada ◽  
Takashi Shirahata ◽  
Kazuko Takahashi ◽  
Josuke Tsunetsugu
Keyword(s):  
Dibromo Derivative

Spectroscopic and photophysical investigations on the nature of localization of rhodamine-123 and its dibromo derivative in different cell lines

1996 ◽  
Vol 6 (4) ◽  
pp. 209-219 ◽  
Author(s):  
Luc Villeneuve ◽  
Prabir Pal ◽  
Gilles Durocher ◽  
David Migneault ◽  
Denis Girard ◽  
...  
Keyword(s):  
Cell Lines ◽  
Rhodamine 123 ◽  
Dibromo Derivative

Internal motion in benzylidene diacetate and its 2,6-dibromo derivative by DNMR and the J method

1989 ◽  
Vol 67 (6) ◽  
pp. 1022-1026 ◽  
Author(s):  
Ted Schaefer ◽  
Craig S. Takeguchi
Keyword(s):  
Double Resonance ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Maximum Magnitude ◽  
Coupling Constant ◽  
Spectral Parameters ◽  
Proton Proton ◽  
Ether Solution ◽  
Spin Spin Coupling ◽  
Dibromo Derivative

The 1H nuclear magnetic resonance spectral parameters are reported for benzylidene diacetate in CS2 and acetone-d6 solutions. The long-range spin–spin coupling constant over six formal bonds, 6J, is used to derive apparent twofold barriers to rotation about the exocyclic C(1)—C bond in the two solutions. The conformation of lowest energy has the α. C—H bond in the benzene plane. The barrier is higher in CS2 than in acetone-d6 solution, in contrast to a molecule like benzyl chloride. In the 2,6-dibromo derivative, the free energy of activation for reorientation about the bond in question is 36 kJ/mol at 165 K in dimethyl ether solution. Such a high barrier implies a very small six-bond proton–proton coupling constant for this derivative because 6J is proportional to the expectation value of sin2θ. The angle θ is zero when the α C—H bond lies in the benzene plane. 6J is −0.051 Hz in acetone-d6 solutions; its sign is determined by double resonance experiments. The question of an angle-independent component of 6J, that is, whether 6J is finite at θ = 0°, is addressed. A maximum magnitude of 0.02 Hz may be present at θ = 0° for the 2,6-dibromo derivative, although a zero magnitude is also compatible with the experimental data. In a compound with a higher internal barrier, α,α,2,6-tetrachlorotoluene, the experimental results are best in accord with a negligibly small 6J at θ = 0°. Keywords: 1H NMR of benzylidene diacetate, spin–spin coupling constants for benzylidene diacetate, DNMR, 2,6-dibromobenzylidene diacetate.

Synthesis of the 4,7-Dibromo Derivative of Highly Electron-Deficient [1,2,5]Thiadiazolo[3,4-d ]pyridazine and Its Cross-Coupling Reactions

2018 ◽  
Vol 2018 (41) ◽  
pp. 5668-5677 ◽  
Author(s):  
Timofey N. Chmovzh ◽  
Ekaterina A. Knyazeva ◽  
Ludmila V. Mikhalchenko ◽  
Ivan S. Golovanov ◽  
Stanislav A. Amelichev ◽  
...  
Keyword(s):  
Cross Coupling ◽  
Coupling Reactions ◽  
Cross Coupling Reactions ◽  
Dibromo Derivative

Die absolute Konfiguration der Juglomycine/The Absolute Configuration of the Juglomycins

1989 ◽  
Vol 44 (3) ◽  
pp. 345-352 ◽  
Author(s):  
Johann Krupa ◽  
Helmut Lackner ◽  
Peter G. Jones ◽  
Karen Schmidt-Bäse ◽  
George M. Sheldrick
Keyword(s):  
Single Crystal ◽  
Structure Analysis ◽  
Absolute Configuration ◽  
X Ray ◽  
The Absolute ◽  
Dibromo Derivative

The absolute configurations of the known juglomycins A (1) and B (2) have been elucidated by single crystal X-ray structure analysis of 1 and its 6,8-dibromo derivative (1b). The structure of 2 has been corrected; it differs from 1 in its configuration at C-4', and not at C-3' as previously assumed. Relationships with the closely related isochromanquinone antibiotics are discussed.

Synthesis of 2-Cinnamoyl-1,3-indandione Derivatives and their Reactions with Hydrazine, Hydroxylamine Hydrochloride, Thiourea, Secondary Amines and Diethyl Oxalate

1979 ◽  
Vol 34 (3) ◽  
pp. 502-506 ◽  
Author(s):  
El - Sayed Afsah ◽  
Fathy Abdel Kader Amer ◽  
Hassan Etman
Keyword(s):  
Ethyl Acetoacetate ◽  
Polyphosphoric Acid ◽  
Hydroxylamine Hydrochloride ◽  
Secondary Amines ◽  
Molar Ratio ◽  
Diethyl Oxalate ◽  
Acetyl Acetone ◽  
Michael Condensation ◽  
Dibromo Derivative

AbstractA series of 2-cinnamoyl-1,3-indandiones (2a-e) were obtained by condensing 1 with aldehydes. Treatment of 2 a with hydrazine or hydroxylamine hydrochloride gave 2-(5-phenyl-2-pyrazolinyl or -isoxazolinyl)-1,3-indandione (3 and 5) respectively, and when treated with thiourea gave 2-(6-phenyl-2-thioxo-4-pyrimidinyl)-1,3-indandione (6).The formation of 2-(β-piperidino-, -morpholino- and -arylmercaptohydrocinnamoyl)- 1,3-indandiones (7a-b and 8a-b) from 2 a was investigated. Compound 7b when treated with hydrazine gave 9. The 2-(α, β-dimorpholinohydrocinnamoyl) derivative (11) was obtained by the action of morpholine on the dibromo derivative (10). The Michael condensation of 2a with ethyl acetoacetate or acetyl acetone was investigated. Treatment of 1 with benzaldehyde in (3:1) molar ratio gave 14, which reacted with diethyl oxalate to give 15. Cyclization of 15 with polyphosphoric acid lead to the formation of 16.

The structure of a hydrocarbon, 2,6,10,10-tetramethyltricyclo[7,2,0,02,7]undec-5-ene, obtained from caryophyllene dihydrochloride: X-ray analysis of the dibromo-derivative

1971 ◽  
pp. 46 ◽  
Author(s):  
K. Gollnick ◽  
G. Schade ◽  
A. F. Cameron ◽  
C. Hannaway ◽  
J. M. Robertson
Keyword(s):  
X Ray ◽  
Dibromo Derivative

ChemInform Abstract: STRUCTURE OF A NEW TRITERPENE ETHER FROM SALACIA PRINOIDES DC, X-RAY INVESTIGATION OF THE DIBROMO DERIVATIVE

1974 ◽  
Vol 5 (17) ◽  
pp. no-no
Author(s):  
D. ROGERS ◽  
D. J. WILLIAMS ◽  
B. S. JOSHI ◽  
V. N. KAMAT ◽  
N. VISWANATHAN
Keyword(s):  
X Ray ◽  
Abstract Structure ◽  
Dibromo Derivative

CONTRIBUTION TO THE STRUCTURE OF DISTYRENES

1938 ◽  
Vol 16b (6) ◽  
pp. 213-217 ◽  
Author(s):  
Léo Marion
Keyword(s):  
Sulphuric Acid ◽  
Dibromo Derivative

Dehydration of αγ-diphenylbutyl alcohol with potassium bisulphate yields 1,3-diphenyl-3-butene which can be oxidized to β-phenylpropiophenone. This 3-butene isomerizes on standing to a crystalline 1,3-diphenyl-1-butene which forms a dibromo-derivative and gives benzaldehyde and hydratropic aldehyde when ozonized. If αγ-diphenylbutyl alcohol is dehydrated with 20% sulphuric acid, it also yields 1, 3-diphenyl-3 butene, but this isomerizes to 1,3-diphenyl-2-butene from which acetophenone is obtained on oxidation.Staudinger's proof of the identity of the pyrolytic distyrene with 1,3-diphenyl-3-butene is not valid since αγ-diphenylpropane, present with the distyrene, produces β-phenylpropiophenone when oxidized.

ChemInform Abstract: NON-CONVENTIONAL NITRATION OF 2,5-DIMETHYLTHIOPHENE AND ITS 3,4-DIBROMO DERIVATIVE

1980 ◽  
Vol 11 (48) ◽  
Author(s):  
H. SUZUKI ◽  
I. HIDAKA ◽  
A. OSUKA ◽  
A. IWASA ◽  
T. MISHINA
Keyword(s):  
Dibromo Derivative

HINDERED CONFORMATIONAL ISOMERIZATION OF 9,10-DIHYDRO-9,9-DIMETHYL-10-METHYLENEANTHRACENES

1964 ◽  
Vol 42 (3) ◽  
pp. 565-571 ◽  
Author(s):  
D. Y. Curtin ◽  
C. G. Carlson ◽  
C. G. McCarty
Keyword(s):  
Room Temperature ◽  
Methyl Groups ◽  
Conformational Isomerization ◽  
Methylene Carbon ◽  
Methyl Group ◽  
First Order ◽  
Methylene Carbon Atom ◽  
Center Ring ◽  
Bromo Compound ◽  
Dibromo Derivative

While the n.m.r. spectrum of 10,10-dimethyl-9-methylene-9,10-dihydroanthracene (I) shows the geminal methyl group absorption as a sharp singlet the spectrum of the dibromo derivative, 10,10-dimethyl-9-dibromomethylene-9,10-dihydroanthracene (II) shows the methyl absorptions as two sharp well-separated peaks at room temperature which coalesce at 91°. 10,10-Dimethyl-9-phenylbromomethylene-9,10-dihydroanthracene (III), and the methyl ester (V) of IV show a broad geminal methyl spectrum at room temperature which separates to a doublet at lower temperatures and sharpens to a singlet at higher temperatures. Rate constants for the first-order processes responsible for the change in spectrum of II, III, and V have been calculated at the coalescence temperatures to be 57 (364 °K), 35 (305 °K), and 61 (300 °K) sec−1, respectively. The ΔH≠'s were used to extrapolate the rates to 305° to give values of 1, 40, and 100 sec−1, respectively. The process being studied is inferred to be the equilibrium between two boat conformations of the center ring in the dihydroanthracene system, rapid interconversion leading to identical environments for the two methyl groups. A comparison with the geometrically similar o,o′-disubstituted biphenyl racemization gives support for this explanation. A number of compounds with a proton and one substituent on the methylene carbon atom of I (substituents: bromine, chlorine, phenyl, carboxy, carbomethoxy, phenylmercapto) and also 10,10-dimethyl-9-phenylcarbomethoxymethylene-9,10-dihydroanthracene (XII) showed a single methyl absorption at room temperature. The methyl spectrum of the mono bromo compound VI did not broaden at temperatures down to 246 °K.

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