Thermal Cyclocondensation of Ethyl (1-Methyl-5- and 6-Benzimidazolyl/benzotriazolyl)aminomethylenepropanedioates

1994 ◽  
Vol 59 (5) ◽  
pp. 1145-1152 ◽  
Author(s):  
Viktor Milata ◽  
Dušan Ilavský ◽  
Igor Goljer ◽  
Lubomír Zalibera
Keyword(s):  
Carboxylic Acid ◽  
Acid Medium ◽  
Uv Spectroscopy ◽  
Reaction Products ◽  
Aprotic Medium ◽  
C Nmr ◽  
Ir And Uv Spectroscopy

Thermal cyclocondensation of starting ethyl (1-methyl-5- and 6-benzimidazolyl/benzotriazolyl)aminomethylenepropanedioates (Ia - Ie) in aprotic medium gives angularly condensed ethyl azolo[4,5-f]quinolonecarboxylates IIa, IIc, IIe and azolo[5,4-f]quinolonecarboxylates IIb, IId, respectively, which are hydrolyzed to the corresponding carboxylic acid III in acid medium. The structure of reaction products has been confirmed by 1H and 13C NMR, IR, and UV spectroscopy.

Etude en rmn 13C de bicyclo[4,n,0]alcanones-3 trans α-substitués. Influence de la nature et de l'orientation du substituant sur le déplacement chimique du 13C du carbonyle

1980 ◽  
Vol 58 (15) ◽  
pp. 1503-1511 ◽  
Author(s):  
Pierre Metzger ◽  
Eliette Casadevall ◽  
André Casadevall ◽  
Marie-José Pouet
Keyword(s):  
Convenient Method ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Uv Spectroscopy ◽  
Substituent Effects ◽  
Fixed Ring ◽  
C Nmr ◽  
Ir And Uv Spectroscopy

The 13C nmr spectra of α, αα, and αα′ substituted trans-fused bicyclo [4,n,0]alkan-3 ones, are described. Substituent effects are discussed in terms of their electron withdrawing character, axial or equatorial configuration, and cyclohexane deformation. 13C=O chemical shifts are shown to be based on the polarization of π bond and on C=O/X non-bonded interactions. As in ir and uv spectroscopy, 13C nmr is a convenient method for detecting an a substituent configuration in fixed ring ketones.

scholarly journals Tannins of Tamarind Seed Husk: Preparation, Structural Characterization, and Antioxidant Activities

2011 ◽  
Vol 6 (6) ◽  
pp. 1934578X1100600 ◽  
Author(s):  
Puksiri Sinchaiyakit ◽  
Yohji Ezure ◽  
Sarin Sriprang ◽  
Supakorn Pongbangpho ◽  
Nasapon Povichit ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Antioxidant Activities ◽  
Uv Spectroscopy ◽  
Degree Of Polymerization ◽  
Dpph Assay ◽  
One Pot ◽  
Acetone Water ◽  
Seed Husk ◽  
C Nmr ◽  
Ir And Uv Spectroscopy

The high content (about 39%) of polymeric tannins in tamarind ( Tamarindus indica L.) seed husk (TSH) was demonstrated, and an extract (crude TSE) with a high content (about 94%) of polymeric tannins was prepared from TSH with a one pot extraction using ethanol/water (3:2, v/v). The crude TSE was further purified with Sephadex LH20 to give one fraction (metTSE) eluted with methanol/water (3:2, v/v) and another (acTSE) eluted with acetone/water (3:2, v/v). The tannins of acTSE were established as polymeric proanthocyanidins (PA) by 13C NMR spectroscopy; this was further confirmed by IR and UV spectroscopy, n-BuOH/HCl and vanillin assays, and from HPLC pattern. The ratio of procyanidins to prodelphinidins was 2:3, and the average degree of polymerization of acTSE was 7. Galloylated flavan-3-ols were not detected in acTSE. The main ingredients of metTSE were confirmed to be polymeric PA by 13C NMR spectroscopy. The antioxidant activities using DPPH and ABTS assays were investigated. The IC50 values of acTSE were 4.2±0.2 (DPPH assay) and 6.2±0.3 μg/mL (ABTS assay).

scholarly journals 7-Bromo-[1,2,5]selenadiazolo[3,4-d]pyridazin-4(5H)-one

Molbank ◽  
10.3390/m1229 ◽  
2021 ◽  
Vol 2021 (2) ◽  
pp. M1229
Author(s):  
Timofey N. Chmovzh ◽  
Oleg A. Rakitin
Keyword(s):  
Mass Spectrometry ◽  
Heterocyclic System ◽  
High Resolution Mass Spectrometry ◽  
Uv Spectroscopy ◽  
Hydrolysis Product ◽  
Selenium Dioxide ◽  
Biologically Active ◽  
Photovoltaic Materials ◽  
Organic Photovoltaic Materials ◽  
Ir And Uv Spectroscopy

New heterocyclic systems containing 1,2,5-chalcogenadiazoles are of great interest for the creation of organic photovoltaic materials and biologically active compounds. In this communication, 3,6-dibromopyridazine-4,5-diamine was investigated in reaction with selenium dioxide in order to obtain 4,7-dibromo-[1,2,5]selenadiazolo[3,4-d]pyridazine. We found that 7-bromo-[1,2,5]selenadiazolo[3,4-d]pyridazin-4(5H)-one, the first representative of the new heterocyclic system, was isolated as a hydrolysis product of the corresponding 4,7-dibromoderivative. The structure of the newly synthesized compound was established by means of elemental analysis, high-resolution mass spectrometry, 1H, 13C NMR, IR and UV spectroscopy, and mass spectrometry.

Cyclic Constraints on Conformational Flexibility in γ-Peptides: Conformation Specific IR and UV Spectroscopy

2013 ◽  
Vol 117 (47) ◽  
pp. 12350-12362 ◽  
Author(s):  
Patrick S. Walsh ◽  
Ryoji Kusaka ◽  
Evan G. Buchanan ◽  
William H. James ◽  
Brian F. Fisher ◽  
...  
Keyword(s):  
Uv Spectroscopy ◽  
Conformational Flexibility ◽  
Ir And Uv Spectroscopy

Quantitative determination of the vinylthio groups in divinyl sulphide copolymers by IR and UV spectroscopy

1981 ◽  
Vol 23 (7) ◽  
pp. 1845-1847
Author(s):  
L.V. Morozova ◽  
E.I. Brodskaya ◽  
D.-S.D. Taryashinova ◽  
S.V. Amosova ◽  
B.A. Trofimov
Keyword(s):  
Quantitative Determination ◽  
Uv Spectroscopy ◽  
Ir And Uv Spectroscopy

scholarly journals Diastereo-specific conformational properties of neutral, protonated and radical cation forms of (1R,2S)-cis- and (1R,2R)-trans-amino-indanol by gas phase spectroscopy

2015 ◽  
Vol 17 (39) ◽  
pp. 25809-25821 ◽  
Author(s):  
Aude Bouchet ◽  
Johanna Klyne ◽  
Giovanni Piani ◽  
Otto Dopfer ◽  
Anne Zehnacker
Keyword(s):  
Electronic Structure ◽  
Gas Phase ◽  
Radical Cation ◽  
Amino Alcohol ◽  
Uv Spectroscopy ◽  
Conformational Properties ◽  
Gas Phase Spectroscopy ◽  
Ir And Uv Spectroscopy

The effects of ionisation and protonation on the geometric and electronic structure of a prototypical aromatic amino-alcohol with two chiral centres are revealed by IR and UV spectroscopy.

(S)-2,2,5,5-Tetramethylthiazolidine-4-carboxylic acid: a compound which exists in the amino acid rather than the zwitterion form

1985 ◽  
Vol 63 (9) ◽  
pp. 2411-2419 ◽  
Author(s):  
Helen Elaine Howard-Lock ◽  
Colin James Lyne Lock ◽  
Philip Stuart Smalley
Keyword(s):  
Amino Acid ◽  
Carboxylic Acid ◽  
Raman Spectra ◽  
Cooh Group ◽  
Infrared And Raman Spectra ◽  
Acid Form ◽  
Hydrogen Atoms ◽  
Cell Dimensions ◽  
Amino Acid Form ◽  
C Nmr

The X-ray crystal structure of (S)-2,2,5,5-tetramethylthiazolidine-4-carboxylic acid, 1, has been determined. Crystals are monoclinic, P21, with cell dimensions a = 11.351(4) b = 8.303(2), c = 11.969(3) Å, β = 116.69(2)°, and Z = 4. The structure was solved by standard methods and refined to R1 = 0.0774, R2 = 0.0670 for 2388 independent reflections. Compound 1 exists in the amino-acid form as shown by two distinctly different C—O bond lengths, 1.209 and 1.309 Å, typical of the COOH group, and by the positions of the hydrogen atoms. The amino-acid form of 1 found in the solid also exists in solution as shown by infrared and Raman spectra. The mass spectra, and 1H and 13C nmr spectra are reported, as well as detailed infrared and Raman spectra for the title compound and several deuterated species.

Reactions of 5-Methylphenanthridinium Iodide with Nucleophiles and Reaction Products Conversion

1993 ◽  
Vol 58 (2) ◽  
pp. 395-403 ◽  
Author(s):  
Jiří Dostál ◽  
Milan Potáček ◽  
Miloslav Nechvátal
Keyword(s):  
Nmr Spectroscopy ◽  
Aqueous Medium ◽  
Reaction Products ◽  
Cyanide Anion ◽  
Carbon Nucleophiles ◽  
Unstable Product ◽  
C Nmr

Reactions of 5-methylphenanthridinium iodide (I) with oxygen, nitrogen, and carbon nucleophiles, respectively, were studied. 5-Methylphenanthridinium iodide (I) yielded in the basic aqueous medium 5-methyl-6-phenanthridone (II) and 5,6-dihydro-5-methylphenanthridine (III). By NMR spectroscopy in the D2O-CD3CN solution 5,6-dihydro-6-deuteroxy-5-methylphenanthridine (IVb) (pseudobase) was observed as an immediate unstable product. 5-Methylphenanthridinium iodide (I) gave the corresponding adducts with methoxide and ethoxide anions, morpholine, piperidine, pyrrolidine, cyanide anion and acetone. Their structure was determined by IR, 1H and 13C NMR spectroscopy. Reactions of 5,6-dihydro-5-methyl-6-morpholinophenanthridine (VII) were followed by NMR spectroscopy. Morpholino adduct VII gave in the CD3CN-D2O solution pseudobase (IVb) and its products of disproportionation: oxophenanthridine II and dihydrophenanthridine III. Treatment of 5,6-dihydro-5-methyl-6-morpholinophenanthridine (VII) with H2O/D2O in (CH3)2CO/(CD3)2CO led to CH3COCH2-/CD3COCD2- adduct XIa/XIb formation, respectively.

Synthesis and Purification of L-Phenylalanine Oligo-Peptides Assisted by Phosphorus Oxychloride

2011 ◽  
Vol 365 ◽  
pp. 150-154
Author(s):  
Ming Xiu Lv ◽  
Li Ming Qiang ◽  
Kui Lu ◽  
Ying Yan Yao
Keyword(s):  
Self Assembly ◽  
Phosphorus Oxychloride ◽  
Inorganic Phosphorus ◽  
The Self ◽  
Reaction Products ◽  
Esi Ms ◽  
H Nmr ◽  
Rp Hplc ◽  
Proper Condition ◽  
C Nmr

Oligo-peptides have been focused on by chemists recently because of the strong bioactivity an activity as drug or precursor of drug. α-Amino acid could self-assemble into oligo-peptides with the assistance of inorganic phosphorus reagents, so it could provide a new method to synthesize peptides. In this paper, the self-assembly reaction of L-Phenylalanine mediated by phosphorus oxychloride were studied by using ESI-MS. The proper condition of self-assembly reaction of L-Phe was reported. The reaction products were purified by RP-HPLC and Phe-Phe dipeptide was characterized by the means of IR, 1H-NMR, 13C-NMR and ESI-MS/MS.

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