6123-63-3Relevant articles and documents
Regio- and stereoselective synthesis of spiro-heterocycles bearing the pyrazole scaffold via [3+2] cycloaddition reaction
Islam, Mohammad Shahidul,Haukka, Matti,Soliman, Saied M.,Al-Majid, Abdullah Mohammed,Rahman, A.F.M. Motiur,Bari, Ahmed,Barakat, Assem
, (2021/10/27)
Herein we reported the utility of one-pot multicomponent based [3+2] cycloaddition reaction transformation to prepare a new two hybrids of spirooxindoles engrafted with pyrazole skeleton. Upon treatment of the electron-deficient olefins based pyrazole motif with in situ the generated azomethine ylides (AY) of sarcosine with the 6-chloro-isatin afforded spiroadducts. To enlighten the regio- and diastereo-selectivity of these spiroheterocycles, single crystal X-ray diffraction analysis was presented. Using Hirshfeld calculations, many short distance contacts such as O…H, Cl…H, N…H, H…C, C…C and Cl…S have a great impact on the molecular packing and the crystal stability of 8a and 8b. The latter showed some Cl…Cl inter halogen interactions (Cl1…Cl3; 3.358 ?). In addition, DFT calculations were used to compute the electronic properties as well as the 1H- and 13C-NMR spectra of the studied systems. Both compounds are polar where 8b (3.995 Debye) has higher dipole moment than 8a (3.414 Debye). The NMR chemical shifts were calculated and found in excellent correlations between the calculated and experimental data were obtained (R2 = 0.94–0.98).
2-Bromo-1-(1H-pyrazol-4-yl)ethanone: Versatile Precursor for Novel Mono- and Bis[pyrazolylthiazoles]
Salem, Mostafa E.,Darweesh, Ahmed F.,Mekky, Ahmed E. M.,Farag, Ahmad M.,Elwahy, Ahmed H. M.
, p. 226 - 234 (2017/02/03)
The synthesis of novel bis(thiazoles) 20a, 20b, 20c and 23a, 23b, 23c is reported. Thus, reaction of 2-bromo-1-(5-methyl-1-phenyl-1H-pyrazol-4-yl)ethanone (6) with the corresponding thioamide derivatives 7a,7b, in refluxing EtOH in the presence of triethylamine, afforded 4-pyrazolylthiazoles 8a, 8b in good yields. On the other hand, the novel bis(thiazoles) 20a, 20b, 20c and 23a, 23b, 23c were obtained from the reaction of 6 with the corresponding benzaldehyde thiosemicarbazones 19a, 19b, 19c, 22a, 22b, 22c in refluxing EtOH. Compounds 19a, 19b, 19c and 22a, 22b, 22c were obtained by condensation of the corresponding bis(aldehydes) 18a, 18b, 18c and 21a, 21b, 21c with thiosemicarbazide.
2-Bromo-1-(1H-pyrazol-4-yl)ethanone: Versatile precursors for novel mono-, bis- and poly{6-(1H-pyrazol-4-yl)-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazines}
Salem, Mostafa E.,Darweesh, Ahmed F.,Farag, Ahmad M.,Elwahy, Ahmed H.M.
, p. 712 - 719 (2016/01/15)
A simple synthesis of novel mono-, bis- and poly{6-(1H-pyrazol-4-yl)-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazines} is reported. The formation of the target compounds was achieved by the reaction of 2-bromo-1-(5-methyl-1-phenyl-1H-pyrazol-4-yl)ethanone with the appropriate aminotriazolethiol or by the reaction of 6-pyrazolyl-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazine-3-thiol with the appropriate di- and poly(bromo) compounds. The structures of the newly synthesized compounds were established by spectroscopy and elemental analyses.
