Reaction between aromatic aldehydes and 3–methyl-1-phenyl-2-pyrazoline-5-one catalyzed by nano-SiO2/HClO4 in water under reflux provided a simple and efficient route for the synthesis of 4-((5-hydroxy-3-methyl-1-phenyl-1H-pyrazol-4-yl)(aryl)methyl)-3-methyl-1-phenyl-1H-pyrazol-5-ol derivatives in high yields.

Chalcones are the condensation product of acetophenone in combination with aromatic aldehydes in the presence of strong base. Chalcones and their metal complexes having prominent role in modern coordination chemistry. These compounds possessing novel structural features, interesting spectral and magnetic properties, have been the subject of intensive research due to their importance in medical,...

In the title compound, C(14)H(13)N(3)O(3), the pyrazoline ring assumes an envelope conformation with the furanyl-bearing C atom at the flap position. The dihedral angle between the furan and nitrobenzene rings is 84.40 (9)°. Weak inter-molecular C-H⋯O hydrogen bonding is present in the crystal structure.

In the title compound, C(16)H(15)N(3)O(2), the planar [maximum deviation 0.156 (2) Å] pyrazoline ring is nearly coplanar with the 3-nitro-phenyl group and is approximately perpendicular to the phenyl ring, making dihedral angles of 3.80 (8) and 80.58 (10)°, respectively. Weak inter-molecular C-H⋯O hydrogen bonding is present in the crystal structure.

We report the first use of a photoinduced 1,3-dipolar cycloaddition reaction in "stapling" peptide sidechains to reinforce a model peptide helical structure with moderate to excellent yields; the resulting pyrazoline "staplers" exhibit unique fluorescence useful in a cell permeability study.

In the title compound, C(16)H(13)N(3)S, the pyrazoline ring forms dihedral angles of 6.89 (14) and 4.96 (11)° with the benzene ring and the benzothia-zole group, respectively. In the crystal, weak C-H⋯N inter-actions link the mol-ecules into chains extending along the b-axis direction.

Highly enantioselective 1,3-dipolar cycloaddition reactions of α-substituted diazoacetates are accomplished by catalysis of the chiral oxazaborolidinium ion. Functionalized 2-pyrazolines are synthesized in high to excellent enantiomeric ratios (up to >99 : 1). The synthetic utility of 2-pyrazoline was expanded via preparation of 2,4-diamino ester compounds bearing a chiral quaternary carbon cen...

New efficient synthetic methods in pyrazoline and pyrazolopyrazine chemistry have been developed starting from 2,2-dichlorovinylacetophenones 1, which were sequentially transformed into 3-aryl-5-dichloromethyl-1-(2-hydroxiethyl)-2-pyrazolines 2, 3-aryl-5-dichloromethyl-1-(2-O-tosylhydroxyethyl)-2-pyrazolines 3, 3-aryl-5-dichloromethyl-1-(2-azidoethyl)-2-pyrazolines 4, 3-aryl-5-dichloromethyl-1-...

In this work, it was of interest to synthesize new series of some 2-[(E)-2-furan-2-yl-vinyl]-quinazolin-4(3H)-ones incorporated into pyrazoline, isoxazoline, pyrimidine or pyrimidine-thione ring systems at position-3 of the quinazoline ring. The antimicrobial activity and antiinflammatory effect of some of these compounds were studied.