Pictet-spengler reaction in the synthesis of condensed benzodiazepines. 2.* Synthesis of new derivatives of 11,12-dihydroquinazoline-[3,2-<Emphasis Type="Italic">c</Emphasis>][2, 3]benzodiazepin-14(6H)-ones

New derivatives of dihydroquinazoline[3,2-c][2, 3]benzodiazepin-14(6H)-ones were synthesized using the Pictet-Spengler reaction of 3-amino-2-(3,4-dimethoxybenzyl)quinazolin-4(3H)-one with aliphatic and heterocyclic aldehydes in acid media.     

Surprising secondary photochemical reactions observed on conventional photolysis of diazotetrahydrofuranones

The formation of C-H insertion products of the terminal N-atom of a diazo group into the α-СН-bond of tetrahydrofuran during direct photolysis of regioisomeric 2,2-dimethyl-5,5-diphenyl and 5,5-dimethyl-2,2-diphenyl-substituted 3-diazotetrahydrofuran-4-ones in THF is dictated by photochemical cycloelimination of the originally formed (1,1-dimethyl-2-oxa-3,3-diphenyl-propano)ketene and oxetanecarboxylic acid derivatives to yield benzophenone. The latter, under subsequent UV irradiation of the reaction mixture, initiates sensitized photolysis of the starting diazoketones resulting in the appearance of the insertion products with the solvent.     

Vortex lattice matching effects in a washboard pinning potential induced by Co nanostripe arrays

An advanced mask-less nanofabrication technique, focused electron beam-induced deposition (FEBID), has been employed on epitaxial Nb thin films to prepare ferromagnetic decorations in the form of an array of Co stripes. These substantially modify the non-patterned films’ superconducting properties, providing a washboard-like pinning potential landscape for the vortex motion. At small magnetic fields B ? 0.1 T, vortex lattice matching effects have been investigated by magneto-transport measurements. Step-like drops in the field dependencies of the films resistivity ρ(B) have been observed in particular for the vortex motion perpendicular to the Co stripes. The field values, corresponding to the middle points of these drops in ρ(B), meet the vortex lattice parameter matching the pinning structure’s period. These disagree with the results of Jaque et al. (2002) [11], who observed matching effects corresponding to the stripe width in Nb films grown on periodically distributed submicrometric lines of Ni.     

The influence of the structure of aliphatic amine on its catalytic activity in the oxidation of anthrone in dimethyl sulfoxide

The catalytic activity of several aliphatic amines in the liquid-phase oxidation of anthrone by molecular oxygen in dimethyl sulfoxide was studied. The kinetic data obtained were compared with the results of quantum-chemical calculations. The catalytic activity of aliphatic amines in the reaction under consideration was directly proportional to an increase in the absolute value of the heat of formation of the corresponding ammonium cation.