Characterization of 4,5‐Dihydro‐1H‐Pyrazole Derivatives by 13C NMR Spectroscopy

The ¹³ C NMR resonances of 19 1‐acyl‐3‐(2‐nitro‐5‐substitutedphenyl)‐4,5‐dihydro‐1H‐pyrazoles, and 19 1‐acyl‐3‐(2‐amino‐5‐substituted)‐4,5‐dihydro‐1H‐pyrazoles, were completely assigned using the concerted application of one‐ and two‐dimensional NMR experiments (DEPT, gs‐HSQC and gs‐HMBC). Copyright © 2012 John Wiley & Sons, Ltd.     

Ketene dithioacetal mediated synthesis of 1,3,4,5-tetrasubstituted pyrazole derivatives and their biological evaluation

Abstract

Ketene dithioacetal mediated chemo- and regioselective synthesis of a series of novel 1,3,4,5-tetrasubstituted pyrazole derivatives (4a-l) integrated with a bioactive indole nucleus was achieved by reacting substituted 2-(1-methyl-1H-indole-3-carbonyl)-3,3-bis-(methylthio)-acrylonitrile (2) and substituted phenyl hydrazine hydrochloride (3) in the presence of a catalytic amount of anhydrous K₂CO₃ under reflux conditions. The structures were ascertained by ¹H NMR, NOESY, ¹³C NMR, FT-IR, and HRMS data. In vitro cytotoxicity evaluation of the synthesized compounds against MCF 7 (breast carcinoma) and normal Vero (monkey kidney) cell lines revealed that the compound 5-(5-Bromo-1-methyl-1H-indol-3-yl)-1-(4-cyano-phenyl)-3-methylsulfanyl-1H-pyrazole-4-carbonitrile (4k) showed significant cytotoxicity against MCF 7 (GI₅₀ = 15.6 µM) with low cytotoxicity against normal Vero cell line. Most of the synthesized compounds were also found to possess excellent anti-inflammatory and antioxidant (DPPH, NO, H₂O₂ and SOR) potential.     

Some Novel Thiazoline and Thiazolidinone Derivatives Surmounted on Substituted Pyrazole Moieties as Potential Antipyretic Agents

Six novel series of substituted thiazoline (V, VI, VII and VIII) and thiazolidinone derivatives (IX and X) resulting from 2,3-dihydro-1, 5-dimethyl-3-oxo-2-phenyl-1H-pyrazole-4-carbaldehyde (I) and 1-phenyl-3-p-tolyl-1H-pyrazolc-4-carbaldehyde (II) were synthesized. The course of this synthesis included the preparation of two new scries of disubstituted thiosemicarbazone precursors (III and IV) which were cyclized with phenacyl bromide, ethyl 2-chloroacetoacetate as well as ethyl bromoacetatc to afford the target thiazolines and thiazolidinoncs. The antipyretic activity of some representative compounds was performed.     

Crystal structure of a synthetic anabolic agent: stanazolol ethanol solvate, 17β-hydroxy-17α methylandrostano[3,2-c]pyrazole ethanoate

The crystal and molecular structure of 17-hydroxy-17 methylandrostano[3,2-c]pyrazole ethanoate (stanazolol ethanol solvate), C₂H₃₀N₂OC₂H₅OH, has been determined by direct methods and refined by full-matrix least squares to a final R of 0.0577 for 4021 observed reflections and 245 parameters using Cu K radiation, = 1.54178 Å. The compound crystallizes in space group P2₁2₁2₁ with Z = 4 molecules per unit cell. In the steroid skeleton the ring A adopts a half-chair conformation, being considerably strained, as a consequence of the fused planar pyrazole ring E. Rings B and C however are chairs and ring D has a 13,14 half-chair conformation. All rings of the steroid skeleton are trans-connected. The OH group of the solvated ethanol molecule is hydrogen bonded to the -oriented carbonyl substituent O(20) of ring D. The molecules are further held together in the crystal structure by head–tail hydrogen bonding between N(1)H in the pyrazole ring and O(20), which consequently is an acceptor for the two H-bonds. Overall the molecule lacks any significant curvature with no interplanar dihedral angle greater than 7°. Possible binding modes of stanazolol with the human androgen receptor are discussed.     

Hydrothermal Synthesis and Crystal Structure of One Novel 1-D Copper(Ⅱ)-organic Framework:{[Cu_2(PP)_2(CBPC)]_2·7H_2O}_n

One novel 1-D copper(Ⅱ)-organic compound,namely {[Cu2(PP)2(CBPC)]2·7H2O}n(1,H2CBPC=1-[(2'-carboxybiphenyl-4-yl)methyl]-2-propylimidazole-4-carboxylic acid,HPP=3-(2-pyridyl)pyrazole),was synthesized under hydrothermal conditions.X-ray diffraction analyses reveal that the two Cu(Ⅱ) ions in the distorted dimer [Cu2(PP)2] of 1 are linked by the carboxylate oxygen atoms on the phenyl and imidazole rings,respectively,forming one interesting snake-like chain.Single-crystal X-ray analyses reveal that it crystallizes in monoclinic,space group C2/c with a=30.656(8),b=12.715(3),c=22.405(5),β=122.758(3)°,V=7344(3)3,Z=4,Mr=1681.65,Dc=1.521 g/cm3,F(000)=3464,μ=1.221 mm-1,the final R=0.0453 and wR=0.1023 for 4617 observed reflections with Ⅰ 2σ(Ⅰ).     

Tetrabutylammonium hydrogen sulfate mediated domino reaction: synthesis of novel benzopyran-annulated pyrano[2,3-c]pyrazoles

A tetrabutylammonium hydrogen sulfate (TBA-HS) mediated procedure for one pot synthesis of novel benzopyran-annulated pyrano[2,3-c]pyrazoles via domino/Knoevenagel-hetero-Diels-Alder reaction has been demonstrated.     

苯驳三氮唑胺烷基化及N一取代芳胺的简便合成

苯骄三氮哇、胺和甲醛在乙晾溶液中发生Mannich反应，生成胺烷基化的苯骄三氮哇衍生物，胺可以是芳香或杂环一级、二级胺，产率很高.上述反应生成的苯骄三氮哇衍生物在硼氢化钠作用下或与格氏试剂反应生成二级或三级芳胺，该法操作简便，条件温和，无副反应.