Cooperative action of hydrogen and halogen bonding in the reaction of 3-(3,5di-tert-butyl-4-hydroxyphenyl)-1-phenylprop-2-en-1-one with HCl or HBr in alcohol medium under microwave irradiation (20 W, 80 C, 10 min) allows the isolation of the haloetherification products (2S,3S)-3-(3-tert-butyl-5-chloro-4hydroxyphenyl)-2-chloro-3-ethoxy-1-phenylpropan-1-one, C 21 H 24 Cl 2 O 3 , (2S,3S)-2bromo-3-(3-tert-butyl-5-bromo-4-hydroxyphenyl)-3-methoxy-1-phenylpropan-1one, C 20 H 22 Br 2 O 3 , and (2S,3S)-2-bromo-3-(3-tert-butyl-5-bromo-4-hydroxyphenyl)-3-ethoxy-1-phenylpropan-1-one, C 21 H 24 Br 2 O 3 , in good yields. Both types of noncovalent interactions, e.g. hydrogen and halogen bonds, are formed to stabilize the obtained products in the solid state.research papers

The crystal structure of the title compound, C20H16BrN3O2, was determined using an inversion twin. Its asymmetric unit comprises two crystallographically independent molecules (A and B) being the stereoisomers. Both molecules are linked by pairs of N—H...O hydrogen bonds, forming a dimer with an R 2 2(16) ring motif. The dimers are connected by further N—H...O and N—H...N hydrogen bonds, forming chains along the c-axis direction·C—Br...π interactions between these chains contribute to the stabilization of the molecular packing. Hirshfeld surface analysis showed that the most important contributions to the crystal packing are from H...H, C...H/H...C, O...H/H...O, Br...H/H...Br and N...H/H...N interactions.

The reaction of Michael addition interaction of 3-phenyl-2-(thiophene-2-carbonyl)acrylonitrile, 2-(thiophene-2-carbonyl)-3-(p-tolyl)acrylonitrile, 3-(4-methoxyphenyl)-2-(thiophene-2-carbonyl)acrylonitril, as well as 3-pyridinyl-2-(thiophene-2-carbonyl)acrylonitrile with acetoacetanilide made it possible to produce substituted hexanones and 3,4-dihydro-2H-pyrane derivatives. Structures of synthesized compounds were acknowledged by NMR and X-Ray structural analysis.

In the title compound, C24H35NO2, the planes of the two aromatic rings form a dihedral angle of 72.76 (4)°. In the crystal, mol­ecules are linked by O—H⋯O and O—H⋯N hydrogen-bond inter­actions, forming an extended two-dimensional framework parallel to the ab plane.

C23H27BrO2, P21/n (no. 14), a = 10.3200(18) Å, b = 15.905(3)(6) Å, c = 12.913(2) Å, β = 97.683(4), V = 2100.6(6) Å3, Z = 4, Rgt(F) = 0.0319, wRref(F2) = 0.0872, T = 296(2) K.