摘要:

The cycloaddition of 1-methoxyindene2to dimethyl acetylenedicarboxylate to form a fused cyclobutene system3is discussed. Photochemical ring enlargement of3leads to a benzocycloheptatriene system5while reduction yields a dihydro derivative4. Saponification of3followed by photochemical ring expansion yields the diacid7which is subsequently hydrolyzed and decarboxylated to ketoacid8.

ISSN:0008-4042    

DOI:10.1139/v70-268

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

The cycloaddition of 1-dimethylaminoindene (2) to dimethyl acetylenedicarboxylate to form a fused cyclobutene system3is discussed. Compound3underwent two modes of ring opening to yield either the indene–maleate system4or the benzocycloheptatriene system5depending on reaction conditions. The synthesis of a number of multifunctional benzotropones from5is discussed.

ISSN:0008-4042    

DOI:10.1139/v70-269

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

The formation of nitrogen monomers by the reaction of Ru(NH3)5(H2O)2+andcis-Ru(NH3)4(H2O)22+with N2has been shown to be first order in N2and second order overall. The formation of bridging N2dimers by the reaction of the ruthenium(II) pentaammine and tetraammine with the monomers has been shown to be second order overall.The reactions were studied in a H2SO4–K2SO4electrolyte pH3.3, μ = 0.30. The ruthenium(II) species were prepared by controlled potential reduction of known ruthenium(III) species at −0.50 V at a Hg cathode. The reactions of the reduced species with N2or the monomers were followed spectrophotometrically.The second order rate constant at 25 °C and the activation energy for the substrate Ru(NH3)5(H2O)2+with the respective nucleophiles are: N2, 8.0 × 10−2 M−1s−1, 22.0 ± 0.1 kcal/mole; Ru(NH3)5N22+, 3.6 × 10−2 M−1s−1, 19.9 ± 0.5 kcal/mole; Ru(NH3)4(H2O)N22+, 2.7 × 10−2 M−1s−1, 20.4 ± 0.8 kcal/mole. For the substratecis-Ru(NH3)4(H2O)22+the values are: N2, 1.0 × 10−1 M−1s−1, 20.4 ± 0.2 kcal/mole; Ru(NH3)5N22+, 6.8 × 10−2 M−1s−1, 18.2 ± 0.1 kcal/mole; Ru(NH3)4(H2O)N22+, 7.2 × 10−2 M−1 s−1, 17.1 ± 0.2 kcal/mole.

ISSN:0008-4042    

DOI:10.1139/v70-270

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

The radiation chemistry of ethanol has been investigated by pulse radiolysis with emphasis on the decay kinetics and yield of the solvated electron, e−EtOH, in neutral and alkaline solution. Computer calculations show that the experimental data are most consistent with a yieldG(e−EtOH) = 1.7 molecules/100 eV, and a pseudo first-order half life for e−EtOH,which corresponds to a second-order rate constantk(e− + EtOH) = 7 × 103 M−1s−1.Rates of reaction of the electron with acetaldehyde and C6F12have been determined to be 4.0 ± 0.5 × 109and 2.5 ± 0.5 × 109 M−1s−1, respectively.The empirical square root formula for spur scavenging kineticsis obeyed for scavenging of the radiation produced positive ion.

ISSN:0008-4042    

DOI:10.1139/v70-271

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

Reduction of pyrrylthiol esters with Raney nickel will yield, under specified conditions, the corresponding hydroxymethyl- or methylpyrroles. Evidence for at least two reduction mechanisms is presented. A convenient synthesis of a previously difficultly accessible pyrrole (1f) related to the coproporphyrins is described.

ISSN:0008-4042    

DOI:10.1139/v70-272

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

Stability constants have been measured for the formation of 1:1 complexes between eight divalent metal ions and six carboxylate anions. For each anion the stabilities of the complexes follow the order Pb2+ > Cu2+ > Cd2+ > Zn2+ > Ni2+ ~ Co2+ > Ca2+ ~ Mg2+. The stabilities of the complexes with each metal ion are directly related to the basicities of the anions, and little or no bidentate chelation occurs between these metal ions and acetoxyacetic acid orN-acetylglycine.

ISSN:0008-4042    

DOI:10.1139/v70-273

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

Solutions of N2O in liquid formamide (dielectric constant 109) gave a yield of N2during γ-radiolysis ofG(N2) = 3.3 ± 0.3. Competition between N2O and other scavengers, including water, ethanol, acids, AgNO3, and CdI2strongly resembled the pattern of reactivity characteristic of solvated electrons found in other polar liquids. Furthermore, the yield obtained (3.3) was consistent with the high dielectric constant and predicted for the free-ion yield by Freeman's model assuming a total ionization of 4.7. However, the absence of an absorption band in nanosecond pulse radiolysis experiments suggests that solvated electrons were not present 10−9 s after the passage of the ionizing radiation. It is quite possible that in this system "solvent anions" (or other reactive reducing ions) were formed in yield equal to the "free-ion" yield. This presupposes that formamide anions readily reduce N2O and Ag+, are inactivated by H+and do not react with water and alcohols.The high dielectric constant apparently leads to large yields of comparatively long-lived (> 10−7 s) reducing ions (free-ion yield of 3.3) accompanied by rather small yields of H atoms and simple molecular decomposition products. In these respects the radiolysis decomposition of formamide resembles that of water.

ISSN:0008-4042    

DOI:10.1139/v70-274

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

In the presence of an acid,N-nitrosopiperidine photolytically adds to conjugated dienes to give 1:1 adducts in excellent yield. While the major products are thesyn- andanti-isomers of piperidino α,β-unsaturated oxime derived from 1,4-addition, similar types of oximes derived from 1,2-addition are also obtained. The ratio ofsyn- andanti-oximes is determined by the relative configurational and the conformational stabilities of the two forms. The nuclear magnetic resonance (n.m.r.) chemical shifts and coupling constants provide useful information for the determination of the configuration and conformation of the oximes. A comparison of the n.m.r. data from α,β-unsaturated oximes indicates that the α-proton generally resonates at a lower field than the β-proton in contrast to the chemical shifts of α,β-unsaturated carbonyl compounds. The photoaddition of nitrosopiperidine to cycloheptatriene gave tropone oxime, probably through the elimination of piperidine from the 1:1 adduct.

ISSN:0008-4042    

DOI:10.1139/v70-275

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

A series of 2-aminomethyl-benzhydrols (3) was prepared by-different methods; starting with substituted isoindolines (1), phthalides (4), or cyanobenzophenones (7).

ISSN:0008-4042    

DOI:10.1139/v70-276

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

Mössbauer spectra, electric dipole moment, and infrared data are reported for several complexes of the type (i) RSnX3(AA) and (ii) RSnX(AB)2(where R = C4H9, C6H5; X = Cl, NCS; AA = α,α′-dipyridyl,o-phenanthroline, 8-aminoquinoline; AB = oxinate, 2-pyridinethiol 1-oxide). Quadrupole splittings and dipole moments indicate a similar octahedral structure is present in all the complexes studied; in type (i) two X groups aretransand in type (ii) the R and X groups arecisto each other. Isomer shifts reveal an order of bond polarity Sn—O ≈ Sn—NCS > Sn—Cl > Sn—

ISSN:0008-4042    

DOI:10.1139/v70-277

出版商:NRC Research Press    

年代:1970

数据来源: NRC