Pyridazines. LXX. Reactions of azidoazolopyridazines with unsaturated compounds

Cycloaddition reactions of azidoazolopyridazines with unsaturated esters, cyclic enol ethers, styrene, 2-vinyl-pyridine, bicyclo[2.2.1]heptene, dicyclopentadiene and dehydrobenzene were investigated. The reaction proceed via the intermediate Δ² -1,2,3-triazolines which were in most cases termolabile and decomposed further to give the final products which were enamines, imines of fused aziridines.     

Reactions of some pyrrole‐2,3‐diones with hydrazine hydrate and o‐phenylenediamine

2,3‐Dihydro‐1H‐pyrrole‐2,3‐diones 1a‐d react with hydrazine hydrate 2 and o‐phenylenediamine 4 under different conditions to yield the pyrazole‐3‐carboxamide derivatives 3a‐d , the pyrrol‐2‐ones 5a‐d and the quinoxaline‐2‐one derivatives 6a‐d , respectively. Hydrolysis of the quinoxaline‐2‐one derivatives 6a‐d gave a substituted furo[2,3‐b]quinoxaline 7 . The structures of the synthesized compounds were assigned on the basis of analytical results as well as spectroscopic data.     

Reactions of 2,3-dihydro-1H-cyclohepta[b]pyrazines with acyl halides

2 When3-dihydro-1H-cyclohepta[b]pyrazine ( 3 ) was treated with acetyl chloride under the Friedel-Crafts conditions, its pyrazine ring opened to afford 2-[N'-acetyl-(2-aminoethyl)amino]tropone. Reactions with propionyl and butyryl chloride also gave similarly ring-opened products. On the other hand, aromatic benzoyl chlorides reacted with compound 3 to afford N-benzoyl-substituted 2,3-dihydro-1H-cyclohepta[b]pyrazines, in addition to ring-opened compounds.     

Reactions of some early transition metal halides with sulphur containing heterocumulenes

The reactions of some early transition metal halides with sulphur bis(t-butylimide) (bns), PhNSO, MeNCS and PhNCS have been studied. The complexes TiCl₄,bns, TiCl₃OR,bns (R = Me, Prⁿ), ZrCl₄,bns, VOCl₃,bns, VOCl₂OMe,bns, TiCl₄PhNSO, TiCl₄PhNOS, TiCL₃OMe,PhNSO, ZrCl₄PhNSO, ZrCl₄,NeNCS and ZrCl₄PnNCS have been isolated and characterised; the ligand bns appears to act as a bidentate ligand.     

Reactions of 2,3-dichloro-1-propene with sulfur and tellurium in the system hydrazine hydrate-KOH

2,3-Dichloro-1-propene reacts with sulfur dissolved in the system hydrazine hydrate-KOH (with formation of K₂S₂ or K₂S) to afford bis(2-chloro-1-propene-3-yl)sulfide as the main product in both cases. Under similar conditions tellurium induces β-elimination of both chlorine atoms resulting in the formation of allene and complete regeneration of tellurium metal.     

Reactions of phosphorus halides with urethane

By the reaction of phosphorus trichloride, thiophosphoryl chloride, phosphorus oxychloride and phosphorus pentachloride with urethane in stoichiometric ratio 1:1 or 1:2 in benzene, compounds of the type

and

(X = S, O or Cl; n = 1 or 2) have been synthesized. A probable mechanism for their formation has also been suggested.     

Reactions of trialkylborines with hydrazine and phenylhydrazine

Summary With hydrazine and phenylhydrazine trialkylborines form complex compounds which decompose when heated with formation, respectively, of 1,2-bisdialkylborinohydrazines and 1-dialkylborino-2-phenylhydrazines.     

Reactions of 2-benzoselenopyrylium salts with hydrazine: a new easy access to 5H-2,3-benzodiazepines

While the solvent-free reactions of the 2-benzoselenopyrylium salts (9) with methyl- or phenylhydrazine afforded the 1-hydrazino-1H-isoselenochromenes (11, 12), the treatment of the salts (9) with anhydrous hydrazine in dry acetonitrile resulted in a ring transformation to give the 5H-2,3-benzodiazepines (13) in one-pot under mild conditions in moderate yields.     

Reactions of polyhalogenopyridines. 12. Reactions of 4-pentafluoroethylthio-2,3, 5,6-tetrafluoropyridine with nucleophilic agents

The reactions of 4-perfluoroethylthio-2,3,5,6-tetrafluoropyridine with various nucleophilic agents were investigated. It was shown that the pentafluoroethylthio group is inert toward N- and O-nucleophiles.For Communication 11, see [1].Chernogolovka Institute of Chemical Physics, Russian Academy of Sciences, Chernogolovka. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 932–935, July, 1996. Original article submitted June 22, 1996.     

Reactions of 2-aminopyridine with picryl halides

2-Aminopyridine reacts with picryl halides to give mixtures of 1-picryl-2-(N-picrylimino)-1,2-dihydropyridine and 2-(N-picrylamino)pyridine. When picryl fluoride is treated with an excess of 2-aminopyridine, the 1-picryl-2-(N-picrylimino)-1,2-dihydropyridine reacts further with 2-aminopyridine to yield two molecules of 2-(N-picrylamino)pyridine in a reaction catalyzed by the by-product, hydrogen fluoride. In contrast, the compositions of the mixtures obtained from the reactions of picryl chloride and picryl bromide with excess 2-aminopyridine are stable in their reaction media.