Volume 53, Nº 6 (2017)

Reactions of N-(2,2,2-trichloroethyl)arenesulfonamides with primary alkyl bromides and iodides, allyl bromide, chloroacetonitrile, and benzyl chloride in acetonitrile on heating in the presence of potassium carbonate gave the corresponding N-alkyl-N-(2,2,2-trichloroethyl)arenesulfonamides.

An efficient synthesis of alverine via iron-catalyzed double cross-coupling of (2E)-3-chloro-N-[(2E)-3-chloroprop-2-en-1-yl]-N-ethylprop-2-en-1-amine with phenylmagnesium bromide is described.

Immobilization of polyethylene glycol-substituted 1-methylimidazolium bromide on the surface of magnetic Fe₃O₄ nanoparticles through hexane-1,6-diyldicarbamate linker afforded a powerful and reusable heterogeneous phase-transfer catalysis which was successfully used for regioselective ring opening of epoxides with azide and nitrite anions in aqueous medium. The new catalyst can readily be recovered by simple magnetic decantation and recycled several times without appreciable loss of catalytic activity.

The oxidation of monoterpene thiols with chlorine dioxide afforded new water-soluble sulfonic acids and their derivatives (sulfonothioates and sulfonyl chlorides). The reaction of terpene thiols with ClO₂ gave the corresponding trisulfides. Sulfonothioates with a pinane skeleton showed antibacterial and antifungal activity.

The reaction of chloroacetamide with 2 equiv of γ-aminobutyric acid potassium salts provides a convenient method for the synthesis of substituted 4-[(2-amino-2-oxoethyl)amino]butanoic acids. Alkylation products of 2-aminoacetic and 3-aminopropanoic acid with chloroacetamide were isolated. Thermal cyclization of substituted 4-[(2-amino-2-oxoethyl)amino]butanoic acids afforded 2-(2-oxopyrrolidin-1-yl)acetamides.

Reactions of 4-amino-2-aryl-6-chloropyridine-3,5-dicarbonitriles with primary and secondary amines afforded 2-alkylamino-4-amino-6-arylpyridine-3,5-dicarbonitriles which showed solid-sate fluorescence in the violet or blue region with the emission maxima in the λ range 400–460 nm.

The reaction of methyl 4-aryl-2,4-dioxobut-2-enoates with 4-aminobenzenesulfonamide in acetic acid–ethanol (1: 1) afforded methyl (2Z)-4-aryl-4-oxo-2-(4-sulfamoylanilino)but-2-enoates which reacted with ninhydrin in glacial acetic acid to give 3-aroyl-4-(4-sulfamoylanilino]-5H-spiro[furan-2,2′-indene]-1′,3′,5-triones.

Electron impact mass spectra of alkyl 4-alkoxy-5-amino-3-methylthiophene-2-carboxylates were studied for the first time. These compounds, except for 4-(1-ethoxyethoxy) and 4-(ferrocenylmethoxy) derivatives, give rise to a stable molecular ion whose decomposition follows three pathways. The main fragmentation pathway of the molecular ion is elimination of alkyl radical from the 4-alkoxy group, the second pathway involves expulsion of alkoxy group from the ester moiety, and the third pathway is decomposition of the thiophene ring. The molecular ions of 4-(1-ethoxyethoxy)thiophenes decompose mainly via elimination of ethyl vinyl ether molecule with formation of [M–VinOEt]⁺ · odd-electron ion, and fragmentation of the latter follows general pathways. In the mass spectra of 4-(ferrocenylmethoxy)thiophenes the most abundant are ferrocenylmethyl ion with m/z 199 (I_rel 100%) and fragment ions derived therefrom.

Conformational study of 5-bromo-2-(2-methylpropyl)-5-nitro-1,3,2-dioxaborinane at the DFT PBE/3ξ level of theory revealed the only sofa–sofa interconversion pathway through a transition state corresponding to 2,5-twist conformer. The barrier to internal rotation of the axial nitro group is several times higher than that for the equatorial nitro group. According to the ¹H, ¹³C, and ¹¹B NMR, IR, and X-ray diffraction data, the main autooxidation products of 5-bromo-2-(2-methylpropyl)-5-nitro-1,3,2-dioxaborinane are 2-bromo-2-nitropropane-1,3-diol and boric acid.

Alkylation of 4,5-disubstituted 4H-1,2,4-triazole-3-thiols with methyl chloroformate and ethyl chloroacetate chemoselectively afforded the corresponding S-alkyl derivatives, whereas the alkylation of 5-benzyl-4-phenyl-4H-1,2,4-triazole-3-thiol with methyl 3-bromopropanoate gave an inseparable mixture of S- and N-alkylation products. Hydrazinolysis of S-(5-benzyl-4-phenyl-4H-1,2,4-triazol-3-yl) methyl carbonothioate involved anomalous cleavage with formation of the initial 4,5-disubstituted 1,2,4-triazole and methyl hydrazinecarboxylate.

Reactions of tetracyanoethylated pregnenolone with ammonia and amines in anhydrous medium at reduced temperature afforded new ionic pregnenolone derivatives, ammonium (aminium) 23,24,24-tricyano- 3β-hydroxy-20-oxo-21-nor-17β-cholane-5,21-dien-24-ides.

The reaction of trifluoromethanesulfonamide with trifluoro-N-(prop-2-yn-1-yl)methanesulfonamide in the system t-BuOCl–NaI afforded N-[(2E)-2,3-diiodoprop-2-en-1-yl]trifluoromethanesulfonamide.

The reaction of 1-phenyl-2-[6-phenyl-3-(pyridin-2-yl)-1,2,4-triazin-5-yl]ethanone with 1,2-dehydrobenzene generated in situ from anthranilic acid and excess isoamyl nitrite afforded in one step 1-(pyridin-2-yl)-4-phenylisoquinoline-3-carbonitrile. This reaction may be regarded as a non-cyanide method for the synthesis of 3-cyanoisoquinolines.