The dehydrogenation of piperidine has been studied and found to have an order of -1.5 with respect to the hydrogen partial pressure. By combining these results with those obtained for pyridine hydrogenation on the same catalyst a complete rate equation for piperidine dehydrogenation together with the stoichiometric number of the rate-determining step of these reactions could be derived. This nu...

In the title mol-ecule, C(27)H(24)N(2)O, the piperidine ring adopts a boat conformation. The acetyl group at position 1 has a bis-ectional orientation. The two phenyl rings attached to the piperidine ring at positions 2 and 6 have bis-ectional and axial orientations, respectively, and make a dihedral angle of 75.27 (10)°. The phenyl-acetonitrile group at position 4 has an equatorial orientation...

Studies on the dimer of o-ketosuccinamic acid indicate that its structure is 4,6-dihydroxy-2-oxo-piperidine&carboxamide-4,6-dicarboxylic acid. The dimer was converted in acid solution to 2-hydroxy-pyridine-4,6-dicarboxylic acid; ultraviolet spectral evidence was obtained for intermediates in this transformation and studies with L-[4J4C]asparagine conmrned the pathway. On hydrogenation the dimer...

In the title compound, C(21)H(25)NO(2), the piperidine ring adopts a twisted boat conformation characterized by puckering parameters θ = 89.5 (1) and ϕ = 257.5 (2)°. The phenyl groups are located in equatorial and axial positions on the central piperidine ring, while the methyl group is in an equatorial position. The dihedral angle between the phenyl rings is 49.8 (1)°. An intra-molecular C-H⋯O...

In the title hydrate, C16H23BrN2O·2H2O, the organic mol-ecule features a strong intra-molecular O-H⋯N hydrogen bond. The piperidine ring, in addition, adopts a chair conformation with the exocyclic C-N bond in an equatorial orientation. The water molecules of crystallization are disordered (each over two sets of sites with half occupancy. In the crystal, they associate into corrugated (100) she...

the direct three component modified mannich reaction via condensation of aldehydes, 2-naphthol or 2,7-naphthalendiol and piperidine to generate betti bases has been carried out over l-proline (20 mol%) with high efficiency under solvent free conditions at 70 oc. also, the reaction of aromatic aldehyde and 4-hydroxycoumarin in the presence of l-proline (20 mol%) in the ethanol under reflux condi...

In the title compound, C17H19NO3S2, the maximum deviation of atoms in the 2H-chromene ring system is 0.0097 (14) Å and the piperidine ring adopts a chair conformation. The dihedral angle between the 2H-chromene ring and the piperidine ring (all atoms) is 87.59 (8)°. In the crystal, inversion dimers linked by pairs of C-H⋯O inter-actions generate R 2 (2)(22) loops. Further C-H⋯O hydrogen bonds l...

In the title compound, C(16)H(18)N(2)O(2)S, the piperidine ring adopts a chair conformation. The central 4-thia-zolidinone ring makes dihedral angles of 12.01 (7) and 51.42 (9)°, respectively, with the benzene ring and the least-squares plane of the piperidine ring. An intra-molecular C-H⋯S hydrogen bond stabilizes the mol-ecular structure and generates an S(6) ring motif. In the crystal, mol-e...

In the title compound, C(9)H(12)Cl(2)N(4), the piperidine ring adopts a chair conformation. The electron delocalization of the molecule is indicated by the similar C⋯N distances within the triazine ring and by the double-bond character of the C=N triazine-piperidine connectivity. Weak intra-molecular C-H⋯N hydrogen bonds link the two rings within the mol-ecule, which exhibits a pseudo-mirror pl...