Crystal structure of (2E)-1-(4-ethoxyphenyl)-3-(4-fluorophenyl)prop-2-en-1-one

The title mol­ecule is nearly planar with a slight structural bend involving the carbonyl group. The mol­ecules pack in the crystal by inter­molecular C—H⋯O/F hydrogen bonding, π–π stacking, and H–π inter­actions.

The title mol­ecule, C₁₇H₁₅FO₂, was synthesized by a Claisen–Schmidt condensation with 4-fluoro­benzaldehyde and 4′-eth­oxy­aceto­phenone. The torsion angles between the 4-fluoro­phenyl ring and the alkene and the 4′-eth­oxy­phenyl ring and the 2-propen-1-one are −1.2 (4) and 1.2 (3)°, respectively; however, there is a larger torsion between the bonds comprising the 2-propen-1-one unit of 12.0 (4)°. The crystal packing is stabilized by inter­molecular C—H⋯O/F hydrogen bonding, π–π stacking, and H–π inter­actions.

2-Amino-4,5-dihydrothiophene-3-carbonitriles: A New Synthesis, Quantum Chemical Studies, and Mannich-Type Reactions Leading to New Hexahydrothieno[2,3-d]pyrimidines

trans-2-Amino-4-aryl-5-benzoyl-4,5-dihydrothiophene-3-carbonitriles were prepared either by the reaction of 3-aryl-2-cyanothioacrylamides with α-thiocyanatoacetophenone or by the Michael-type addition of cyanothioacetamide to α-bromochalcones followed by intramolecular cyclization. The mechanism of the first reaction was studied using high-level quantum chemical calculations. Density functional theory (DFT) studies were carried out to determine the mechanism of the first reaction. A new approach toward the construction of the thieno[2,3-d]pyrimidine core system was demonstrated by the reaction of the prepared dihydrothiophenes with HCHO and RNH2 under noncatalyzed Mannich conditions.