title: Synthesis and crystal structures of N-substituted pyrazolines.
abstract: Four pyrazole compounds, 3-(4-fluorophenyl)-5-phenyl-4,5-dihydro-1H-pyrazole-1-carbaldehyde (1), 5-(4-bromophenyl)-3-(4-fluorophenyl)-4,5-dihydro-1H-pyrazole-1-carbaldehyde (2), 1-[5-(4-chlorophenyl)-3-(4-fluorophenyl)-4,5-dihydro-1H-pyrazol-1-yl]ethanone (3) and 1-[3-(4-fluorophenyl)-5-phenyl-4,5-dihydro-1H-pyrazol-1-yl]propan-1-one (4), have been prepared by condensing chalcones with hydrazine hydrate in the presence of aliphatic acids, namely formic acid, acetic acid and propionic acid. The structures were characterized by X-ray single crystal structure determination. The dihedral angles formed between the pyrazole and the fluoro-substituted rings are 4.64(7)° in 1, 5.3(4)° in 2 and 4.89(6)° in 3. In 4, the corresponding angles for molecules A and molecules B are 10.53(10)° and 9.78(10)°, respectively.
authors: Crystallography Unit, School of Physics, Universiti Sains Malaysia, Penang 11800 USM, Malaysia.
authors: Wan-Sin
authors: WS
authors: Loh
authors: Ching Kheng
authors: CK
authors: Quah
authors: Tze Shyang
authors: TS
authors: Chia
authors: Hoong-Kun
authors: HK
authors: Fun
authors: Majal
authors: M
authors: Sapnakumari
authors: Badiadka
authors: B
authors: Narayana
authors: Balladka Kunhanna
authors: BK
authors: Sarojini
mesh_terms: D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D008968:Molecular Conformation; D011720:Pyrazoles / Q000138:chemical synthesis* / Q000737:chemistry*
chemical_list: D011720:Pyrazoles