Facile Access to 2-Selenoxo-1,2,3,4-tetrahydro-4-quinazolinone Scaffolds and Corresponding Diselenides via Cyclization between Methyl Anthranilate and Isoselenocyanates: Synthesis and Structural Features.

A practical method for the synthesis of 2-selenoxo-1,2,3,4-tetrahydro-4-quinazolinone was reported. The latter compounds were found to undergo facile oxidation with HO into corresponding diselenides. Novel organoselenium derivatives were characterized by the H, Se, and C NMR spectroscopies, high-resolution electrospray ionization mass spectrometry, IR, elemental analyses (C, H, N), and X-ray diffraction analysis for several of them.

Crystal structure and Hirshfeld surface analysis of ethyl 6'-amino-2'-(chloro-meth-yl)-5'-cyano-2-oxo-1,2-di-hydro-spiro-[indoline-3,4'-pyran]-3'-carboxyl-ate.

The mol-ecular conformation of the title compound, CHClNO, is stabilized by an intra-molecular C-H⋯O contact, forming an (6) ring motif. In the crystal, the mol-ecules are connected by N-H⋯O hydrogen-bond pairs along the axis direction as dimers with (8) and (14) ring motifs and as ribbons formed by inter-molecular C-H⋯N hydrogen bonds. There are weak van der Waals inter-actions between the ribbons.

Correction: Novel cationic 1,2,4-selenadiazoles: synthesis addition of 2-pyridylselenyl halides to unactivated nitriles, structures and four-center Se⋯N contacts.

Correction for 'Novel cationic 1,2,4-selenadiazoles: synthesis addition of 2-pyridylselenyl halides to unactivated nitriles, structures and four-center Se⋯N contacts' by Victor N. Khrustalev , , 2021, , 10689-10691, DOI: 10.1039/D1DT01322J.

Novel cationic 1,2,4-selenadiazoles: synthesis via addition of 2-pyridylselenyl halides to unactivated nitriles, structures and four-center SeN contacts.

2-Pyridylselenyl halides undergo facile coupling with a triple CN bond of unactivated nitriles. Unprecedented heterocyclization allowed the preparation of a novel class of cationic 1,2,4-selenadiazoles in remarkably high yields. Cationic 1,2,4-selenadiazoles form supramolecular dimers in the crystal via SeN chalcogen bonding, which was studied theoretically.

Crystal structure and Hirshfeld surface analysis of 3-amino-1-oxo-2,6,8-triphenyl-1,2,7,8-tetra-hydro-iso-quinoline-4-carbo-nitrile.

In the title compound, CHNO, the 1,2-di-hydro-pyridine ring of the 1,2,7,8-tetra-hydro-iso-quinoline ring system is planar as expected, while the cyclo-hexa-1,3-diene ring has a twist-boat conformation, with Cremer-Pople parameters = 0.367 (2) A, θ = 117.3 (3)° and φ = 327.

Crystal structure of 1,1'-{(1,1')-[4,4'-(9-fluorene-9,9-di-yl)bis-(4,1-phenyl-ene)]bis-(aza-nylyl-idene)bis(methanylyl-idene)}bis-(naphthalen-2-ol) di-chloro-benzene monosolvate.

The bis-(anil) mol-ecule of the title compound, CHNO·CHCl, contains two anil fragments in the enol-enol form, exhibiting intra-molecular O-H⋯N hydrogen bonds. The two hy-droxy-naphthalene ring systems are approximately parallel to each other with a dihedral angle of 4.67 (8)° between them, and each ring system makes a large dihedral angle [55.

Bromination of bis-(pyridin-2-yl) diselenide in methyl-ene chloride: the reaction mechanism and crystal structures of 1-pyridine-2-selenenyl dibromide and its cyclo-adduct with cyclo-pentene (3a,9a)-2,3,3a,9a-tetra-hydro-1-cyclo-penta-[4,5][1,3]selenazolo[3,2-]pyridinium bromide.

1-Pyridine-2-selenenyl dibromide, CHNSeBr, , is a product of the bromination of bis-(pyridin-2-yl) diselenide in methyl-ene chloride recrystallization from methanol. Compound is essentially zwitterionic: the negative charge resides on the SeBr moiety and the positive charge is delocalized over the pyridinium fragment. The C-Se distance of 1.

The synthesis and crystal structure of 2-(chloro-selan-yl)pyridine 1-oxide: the first monomeric organoselenenyl chloride stabilized by an intra-molecular secondary Se⋯O inter-action.

The title compound, CHClNOSe, is the product of the reaction of sulfuryl chloride and 2-selanyl-1-pyridine 1-oxide in di-chloro-methane. The mol-ecule has an almost planar geometry (r.m.