Chlorination of trans-1,2-Diarylethenes in Chloroform and Acetic Acid

When chlorinated in chloroform, (E)-stilbenes bearing electron-donor substituents in the para position of the benzene ring give threo-1,2-diaryl-1,2-dichloroethanes, while meta-substituted (E)-stilbenes, predominantly erythro isomers, irrespective of the nature of the substituent. The reactions in acetic acid result in preferential formation of threo-1,2-dichloro- and threo-1-acetoxy-1,2-diaryl-2-chloroethanes.     

Synthesis of 3-(Benzotriazol-1-yl)naphthoquinone Derivatives

2,3-Bis(benzotriazol-1-yl)-1,4-naphthoquinone reacts with aliphatic and aromatic amines to give the corresponding 2-amino-3-(benzotriazol-1yl)-1,4-naphthoquinones, and its reaction with alkali gives 2-hydroxy-3-(benzotriazol-1-yl)-1,4-naphthoquinone.     

Thiocyanatoarylation of Diallyl Esters of Phthalic and Isophthalic Acids

Allyl [(2-thiocyanato-3-aryl)propyl](iso)phthalates were prepared by the reaction of arenediazonium tetrafluoroborates with diallyl esters of phthalic and isophthalic acids under anionarylation conditions in the presence of the thiocyanate nuclephile. Independent of reactant ratio, the second allyl fragment fails, under the conditions used, to enter thiocyanatoarylation. Catalysts (copper salts) are required for the reaction to occur.     

Synthesis and Transformations of 2-Hydroxy-3-arylazo-1,4-naphthoquinones

A series of 2-hydroxy-3-arylazo-1,4-naphthoquinones were prepared by coupling of 2-hydroxy-1,4-naphthoquinone with aryldiazonium chlorides. The reactivity of the products toward electrophilic and nucleophilic agents was studied. In reaction with o-phenylenediamine they give condensation products, the corresponding benzo[a]phenazines.     

Reaction of Arenediazonium Tetrafluroborates with N,N-Methylenediacryalmide in the Presence of Thiocyanate Anions

The reactions of arenediazonium tetrafluoroborates with N,N-methylenediacrylamide in H₂O-DMF (1:3) and H₂O-DMSO (1:4) in the presence of thiocyanate anions involve thiocyanatoarylation by one or two multiple bonds to give [(3-aryl-2-thiocyanatopropionylamino)methyl]-2-acryalmides and N,N-methylenebis(2-thiocyanato-3-arylpropionamides).     

Synthesis of benzoquinone derivatives containing benzotriazole fragments

2,3,5,6-Tetrakis(1H-benzotriazol-1-yl)-1,4-benzoquinone was synthesized in 85% yield by reaction of 2,3,5,6-tetrachloro-1,4-benzoquinone with 1H-benzotriazole in pyridine at room temperature. Treatment of 2,3,5,6-tetrakis(1H-benzotriazol-1-yl)-1,4-benzoquinone with piperidine, ω-amino acids, and aromatic amines gave the corresponding 2,5-diamino-3,6-bis(1H-benzotriazol-1-yl)-1,4-benzoquinones.     

Synthesis and study of the structure of the reaction products formed from cyclopenta[<Emphasis Type="Italic">c</Emphasis>]quinolinium quarternary salts and <Emphasis Type="Italic">p</Emphasis>-dimethylaminobenzaldehyde

The presence of active methylene group in the molecules of cyclopenta[c]quinolinium quarternary salts permitted to obtain products of their reaction with p-dimethylaminobenzaldehyde. Structures of the reaction products were established from ¹H and ¹³C NMR spectral data using the correlation spectra. The effect of substituents at nitrogen on the visible absorption spectra was studied. The investigation of formation of the frontier orbitals in the reaction products by quantum chemical calculations revealed the reason of the coloration of the dyes synthesized.     

Cyclization of secondary aromatic amines with formaldehyde and cyclopentanone

Secondary aliphatic-aromatic and aromatic amines react with formaldehyde and cyclopentanone in the presence of perchloric acid to form cyclopenta[c]quinolinium salts in good yields. The yields of the cyclization conditions as a function of reagent ratio and reaction time and temperature were studied, and procedures for isolation and purification of the target compounds were developed.