Ring-opening of cyclic sulfamidates with propargylic sulfonamides yielded substrates for a gold-catalyzed cyclization to yield tetrahydropyrazines. Manipulation of the tetrahydropyrazines, by reduction or using multicomponent reactions, yielded piperazine scaffolds in which substitution of the carbon atoms was varied. Such scaffolds may have value in the synthesis of novel screening compounds w...

In the title compound, (C(5)H(14)N(2))[CuCl(4)], the copper(II) ion has a slightly tetra-hedrally distorted square-planar coordin-ation geometry and the diprotonated piperazine ring adopts a chair conformation. In the crystal structure, cations and anions are linked by inter-molecular N-H⋯Cl hydrogen bonds, forming a three-dimensional network.

In the title compound, C(16)H(18)FN(3)O(2)S(2), the methyl-piperazine ring adopts a chair conformation, while the (2,3-dioxoindolin-1-yl)ethyl unit is linked to one of the N atoms of the piperazine ring via the carbodithio-ate group. In the crystal, each mol-ecule is linked to its neighbors within the ([Formula: see text]03) plane through weak C-H(methyl-ene)⋯O, C-H(ar-yl)⋯O and C-H(methyl-ene)...

The structure-activity relationships within a series of penicillins and cephalosporins containing an N(4)-substituted piperazine-2,3-dione moiety in the C(6)/C(7)-beta-side chain are discussed.

In the title compound, C(28)H(28)Br(2)N(2)O(2), the C=C double bond has an E configuration and the piperazine ring has a chair conformation, with the N-C bonds in equatorial orientations. The dihedral angle between the bromo-benzene rings is 83.1 (4)°. In the crystal, mol-ecules are linked by C-H⋯O and C-H⋯Br hydrogen bonds.

The 3-hydroxy-4-pyridinones (3,4-HP) are well known chelating agents with potential applications in medicinal chemistry. The importance of these compounds has been mostly associated with their high affinity towards hard trivalent metal ions, such as Fe(III), Al(III) and Ga(III), and potential use as decorporating agents in situations of metal imbalance [1]. As part of an ongoing project, beside...