摘要:

Diazotization ofo-aminobenzaldehyde, followed by immediate coupling of the diazonium salt with primary alkylamines, affords unstable l-aryl-3-alkyltriazenes which immediately cyclize to the 4-hydroxy-3-alkyl-1,2,3-benzotriazines. Analogous reaction ofo-aminobenzophenones affords stable 4-aryl-4-hydroxy-3-alkyl-1,2,3-benzotriazines. The 4-hydroxytriazine derived fromo-anthraniloylbenzoic acid undergoes further cyclization spontaneously to a novel spiro-1,2,3-triazine-furan. Diazotization ofo-aminopropiophenone and coupling to methylamine affords a surprisingly stable 4-alkyl-4-hydroxytriazine. Preliminary assay of the biological activity of the 4-hydroxytriazines shows significant cytotoxicity of two members of the series towards M21 melanoma cells in vitro.

ISSN:0008-4042    

DOI:10.1139/v83-031

出版商:NRC Research Press    

年代:1983

数据来源: NRC

摘要:

Hydrazonium(2+) hexafluorosilicate, N2H6SiF6, at room temperature has an orthorhombic(Pbca,Z = 4), pseudotetragonal unit cell (a = 7.605(1) Å,b = 7.586(2) Å,c = 8.543(1) Å). The structure consists of centrosymmetric N2H62+and SiF62−ions arranged in a NaCl-type packing and connected by hydrogen bonds to two-dimensional N2H6–SiF6layers parallel to (001). All H atoms are engaged in hydrogen bonding. Four of the sixbonds to each cation are normal but significantly bent; the other two are trifurcated,, but the out-of-layer component of the trifurcated bond is relatively unimportant. The N2H6SiF6structure is compared in some detail with the structures of other hydrazonium(2+) salts, with particular attention to the N—N bond length, to the "effective" size of the N2H62+ion, and to the tendency of this ion to form bent hydrogen bonds.

ISSN:0008-4042    

DOI:10.1139/v83-032

出版商:NRC Research Press    

年代:1983

数据来源: NRC

摘要:

The yield and reaction kinetics of trapped electrons,and, in several ethylene glycol/D2O glasses have been studied from 6–72 K by pulse radiolysis. An increased D2O concentration is believed to increase the concentration of IR-traps thereby leading to a greaterand to decrease the concentration of VIS-traps thereby increasing the stability of. The yield and stability ofare also increased by lowering the temperature. A redetermination of(1.3 × 104 M−1cm−1at 1800 nm) confirms earlier values.

ISSN:0008-4042    

DOI:10.1139/v83-033

出版商:NRC Research Press    

年代:1983

数据来源: NRC

摘要:

The hydrogen-bonded interactions by water and methanol in the first solvation shell of 2-aminopyrimidine, 2-, 3-, and 4-aminopyridine were determined by calorimetric analysis. The aminopyridines are enthalpically more stable in methanol than in water. This is due to methanol interactions at the amino nitrogen which do not seem to occur in water. The transfer enthalpies from water to methanol are determined primarily by the making and breaking of hydrogen bonds in the two solvents.

ISSN:0008-4042    

DOI:10.1139/v83-034

出版商:NRC Research Press    

年代:1983

数据来源: NRC

摘要:

The energy formula describing bond contributions in terms of the charges carried by the bond-forming atoms is applied to ethylenic compounds. It is shown in what manner σ and π electrons can be treated within the framework of the bond energy theory giving the atomization energy of the vibrationless molecule at 0 K. Proper consideration of zero-point and thermal vibrational energies leads to standard enthalpies of formation. These calculations, which are carried out on the basis of,13C nuclear magnetic resonance spectra, agree with their experimental counterparts, within experimental uncertainties (~0.3 kcal mol−1average deviation).

ISSN:0008-4042    

DOI:10.1139/v83-035

出版商:NRC Research Press    

年代:1983

数据来源: NRC

摘要:

The reaction of (C6H5)2BOH with salicylaldoxime yielded [(C7H5NO2)BC6H5]2via a boron–carbon bond cleavage reaction. Crystals of bis[(salicylaldoximato(2−))phenylboron] are triclinic,a = 9.219(1),b = 11.240(1),c = 12.086(1) Å, α = 100.682(7), β = 112.224(6), γ = 92.189(7)°,Z = 2, space group. The structure was solved by direct methods and was refined by full-matrix least-squares procedures toR = 0.036 andRw = 0.049 for 3433 reflections withI ≥ 3σ(I). The molecule, which has approximateC2symmetry, contains a system of five fused six-membered rings including the first crystallographically characterized B2N2O2ring. The compound is stabilized both by intramolecular N → B coordination and by resonance delocalization and contains boron atoms in a distorted tetrahedral environment. Bond lengths (corrected for libration) are: O—B, 1.469(2)–1.488(2), N—B, 1.602(2) and 1.575(2), C—B, 1.598(2) and 1.599(2) Å.

ISSN:0008-4042    

DOI:10.1139/v83-036

出版商:NRC Research Press    

年代:1983

数据来源: NRC

摘要:

The reaction between mercury (II) chloride andN,N′-dimethylethylenebisdithiocarbamate gave a white precipitate. In an attempted recrystallization from an aqueous–ethanol solution, a cyclic thiourea-type compound,N,N′-dimethyl-2-imidazolidinethione, was obtained. The crystals of this compound are monoclinic,a = 10.388(2),b = 6.139(1),c = 12.291(4) Å, β = 118.64(2), and space groupP21/c. The non-hydrogen atoms of the molecule are planar and the C=S bond length is 1.673(4) Å. The structure was refined by full-matrix least-squares from 642 independent reflections measured on an automatic diffractometer toRandRwof 0.053 and 0.068, respectively.

ISSN:0008-4042    

DOI:10.1139/v83-037

出版商:NRC Research Press    

年代:1983

数据来源: NRC

摘要:

Epoxy allylsilanes can be cyclized with Lewis acids to give cyclic alcohols in a biomimetic synthesis of mono and bicyclic compounds. The allylsilane has a pronounced effect on activating an olefin in this cyclization and producing the exocyclic methylene regioselectively. A short synthesis of karahana ether (5) is reported.

ISSN:0008-4042    

DOI:10.1139/v83-038

出版商:NRC Research Press    

年代:1983

数据来源: NRC