Interaction of benzothieno[2,3-c]pyrylium salts with hydrazine. Derivatives of 5H-[2,3]benzothieno[2,3-e]diazepines

A study has been made of the reaction of 1,3-disubstituted bezothieno[2,3-c]pyrylium salts with hydrazine. It has been shown that 1,3-dialkyl-substituted benzothieno[2,3-c]pyrylium salts interact with hydrazine to give N-amino-1,3-dialkylbenzothieno[2,3-c]pyridines. The presence of a pyrylium ring on one of the positions of the phenyl group leads to a mixture of N-amino derivatives and 5H-[2,3]benzothieno[2,3-e]diazepines. In contrast, 1,3-diphenylbenzothieno[2,3-c]pyrylium perchlorate gives exclusively 5H-[2,3]benzothieno[2,3-e]diazepine.L. M. Litvinenko Institute of Physical Organic Chemistry and Coal Tar Chemistry, National Academy of Sciences of Ukraine, Donetsk 340114. Translate from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp 1137–1140, August, 1998.     

Synthesis ofβ-carboline with the germatrane portion

The 1-oxo-3,3-dimethyl-6-(-trichlorogermyl)ethyl-1,2,3,4-tetrahydroindolo[2,3-c]pyrylium salt, obtained by the acid-catalyzed acylation of 2-(indol-3-yl)dimedone with -trichlorogermylpropionyl chloride and the subsequent reaction with ammonia and triethanolamine, was converted to the corresponding -carboline with the germatrane portion.L. M. Litvinenko Institute of Physicoorganic Chemistry and Carbon Chemistry, Academy of Sciences (NAN) of the Ukraine, Donetsk 340114. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 671–672, May, 1998.     

Experimental Evidence of Intramolecular CAr–H···O=C Hydrogen Bonds in the Structure of (Diaryl)tetrahydrofuranones Using Spectroscopic Tools

The occurrence of bifurcate H‐bonds C_Ar–H···O=C in the structure of (diaryl)‐tetrahydrofuranones was experimentally demonstrated using different methods and techniques. The consistent increasing spin–spin coupling constants ¹J(C,H) of the ortho‐H‐atoms and low‐field shift of v_C=O in IR spectra of 2,2‐(diaryl)tetrahydrofuran‐3(2H)‐ones relative to their 5,5‐diaryl counterparts, as well as pronounced dependence of the ortho‐C–H H‐atoms chemical shifts on the temperature and solvent polarity along with X‐ray diffraction analysis data unambiguously point to the existence of weak C_Ar–H···O=C H‐bonds in these molecules.     

Features of the Reaction of 5-aminoisoxazoles with diethyl 2-oxosuccinate. Synthesis of ethyl 6-hydroxy-isoxazolo[5,4-b]pyridine-4-carboxylates

Chemistry of Heterocyclic Compounds - Condensation of 5-aminoisoxazoles bearing substituents at position 3 with diethyl 2-oxosuccinate sodium salt in trifluoroacetic acid proceeded with the...     

Conversion of 2-ethyl-3,3,5,5-tetramethyl- and 2-ethyl-1,3,3,5,5-pentamethyl-1,2,4,5-tetra-hydro-3h-benz-2-azepines by the action of ethyl propiolate

It has been shown that, on interacting 2-ethyl-3,3,5,5-tetramethyl- and 2-ethyl-1,3,3,5,5-pentamethyl-1,2,4,5-tetrahydro-3H-benz-2-azepines with ethyl propiolate in methanol, fission of the azepine ring occurs at the C(1)–N(2) bond involving a molecule of solvent. The indicated azepines do not react with acetylenedicarboxylic acid ester under these conditions.     

Bifunctionalized Allenes,VII: Two Methods for One‐Pot Synthesis of Sulfonyl‐Functionalized Allenecarboxylates and Phosphorylated Allenes

Two new approaches to the synthesis of sulfonyl‐functionalized allenecarboxylates and phosphorylated allenes are described. 2‐Sulfonyl‐alka‐2,3‐dienoates were readily prepared in an one‐pot reaction by [2,3]‐sigmatropic rearrangement of sulfinato‐substituted 2‐alkynoates, in situ generated from ethyl propynoate and subsequent treatment with lithium diisopropyl (LDA), ketone, trimethylchlorosilane (TMSCl), and the corresponding sulfinyl chlorides. Preparation of 1‐sulfonyl‐alka‐1,2‐dienephosphonates and ‐1,2‐dienyl phosphine oxides consists of the reaction of the lithio compounds, in situ generated from phosphorylated allenes and LDA, with the corresponding sulfonyl chlorides.     

ALKATRIENYL SULFOXIDES AND SULFONES. PART IV. SYNTHESIS AND ELECTROPHILEINDUCED CYCLIZATION REACTIONS OF 3-METHYL-1-METHYLSULFONYLPENTA-1,2,4-TRIENE

A method for synthesis of 3-methyl-1-methylsulfonylpenta-1,2,4-triene (3) by [2,3] sigmatropic rearrangement of 3-methylpent-1-en-4-yn-3-yl methanesulfinate (2), formed in the reaction of 3-methylpent-1-en-4-yn-3-ol (1) with methylsulfinyl chloride has been found. Electrophile-induced reactions of the vinylallenyl sulfone (3) occur in different pathways depending on the used electrophiles. The halogenation leads to the formation of (1E)-2-halo-3-methylene-1-methylsulfonylpenta-1,4-dienes (4) and (5). Reactions with phenylsulfenyl and phenylselenenyl chlorides afford only heterocyclic products, 3-methyl-2-[methylsulfonylmethyl]thiophene (6) in the case of sulfenyl chloride, and a mixture of 2,5-dihydroselenophene (7) and selenophene (8) in the case of selenenyl chloride.     

Synthesis,NMR Spectroscopy,and Molecular Modeling of 2-Methyl-2,3,4,5-tetrahydro-1H-[1]benzothieno[2,3-c]azepine

Russian Journal of Organic Chemistry - A new synthetic approach to fused azepines was demonstrated on an example of the synthesis of 2-methyl-2,3,4,5-tetrahydro-1H-[1]benzothieno[2,3-c]azepine. The...     

Combinatorial properties of virtual braids

We determine the lower central series of the virtual braid group VBn and of the kernels of two different projections of VBn in Sn: the normal closure of the Artin braid group Bn, that we will denote by Hn, and the so-called virtual pure braid group VPn, which is related to Yang Baxter equation. We describe relations between Hn and VPn and we provide a connection between virtual pure braids and the finite type invariant theory for virtual knots defined by Goussarov, Polyak and Viro.