摘要:

2,4,6-Trichloro-s-triazine (cyanuric chloride) has been used to couple glycine ethyl ester with seven carbohydrate derivatives that contain amino groups. The reactions proceed in high yield under mild conditions. The compounds serve as models for the coupling of carbohydrates to proteins by well-defined linkages through amino groups.

ISSN:0008-4042    

DOI:10.1139/v72-320

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

The hydration of a series of ring-substituted trifluoroacetophenones (Z) has been studied by means of u.v. and n.m.r. spectroscopy in DMSO–water and sulfolane–water mixtures. TheW0function is defined aswhereKdis the equilibrium constant for the reactionMixtures of water and sulfolane in all proportions have a dehydrating effect compared to water but mixtures of water and DMSO down to 15 mol % water are more hydrating with respect to the carbonyl group of trifluoroacetophenones than is pure water. An analysis of activity coefficient behavior indicates that the diol, ZH2O, has a higher requirement for solvation by water molecules than does water itself.The rate of the uncatalyzed hydration in aqueous sulfolane drops drastically as the water content of the medium decreases, whereas the rate of the acid-catalyzed reaction is not greatly affected by changes in the solvent composition; a plot of logkfor both catalyzed and uncatalyzed reactions is approximately linear inW0.

ISSN:0008-4042    

DOI:10.1139/v72-321

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

The kinetics of the oxidation of 2-propanol by ruthenium tetroxide in aqueous perchloric acid solutions have been investigated. The results indicate that the two mechanisms pertain; at moderate acidities (1–6.5 MHClO4) the rate determining step involves hydride abstraction while at very high acid concentrations the rate determining step becomes carbonium ion formation.

ISSN:0008-4042    

DOI:10.1139/v72-322

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

The photodecomposition of cyclohexane sensitized by Cd(3P1) atoms has been studied in the vapor phase at 355 °C. The primary decomposition gives hydrogen atoms and cyclohexyl radicals. The volatile products of the decomposition are H2, cyclohexene, propylene, ethane, ethylene, methane, propane, butadiene, and methylcyclopentane. Products other than H2and cyclo-C6H10arise from unimolecular reactions of cyclohexyl radicals, the most important such process being the production of propylene and allyl radicals. Hydrogen yields decrease rapidly with time because of H-atom scavenging reactions involving olefinic products. The quantum yield of molecular hydrogen formation at the shortest exposure time examined is 0.53.

ISSN:0008-4042    

DOI:10.1139/v72-323

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

The photolysis of benzoic acid in the vapor phase has been investigated in a flow system at temperatures ranging from 110–305 °C, pressures from 0.06–1.73 Torr, and at various incident light intensities. Carbon dioxide and benzene are the main products and carbon monoxide is a minor product. The rate of formation of carbon dioxide is proportional to the first power of the light intensity and is independent of benzoic acid concentration at pressures from 0.29–1.73 Torr. The activation energy for carbon dioxide formation is approximately 3 kcal per mol. A radical chain mechanism has been suggested, in which initiation results from decomposition of vibrationally excited ground state benzoic acid molecules, and termination occurs at the wall. A molecular mechanism is a possibility if the rate of formation of vibrationally excited ground state is a function of temperature.

ISSN:0008-4042    

DOI:10.1139/v72-324

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

The 10H-isoindolo[2,3-c][3]benzazepines, "Schöpfs base VI" (4a) and its 4-methoxy derivative4b, have been prepared by a new and facile synthesis which utilized intermediates derived from phthalideisoquinoline alkaloids.

ISSN:0008-4042    

DOI:10.1139/v72-325

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

A new metabolite of phenacetin was identified as 4-hydroxy-3-methylthioacetanilide (11). The synthesis of11and the isomeric 4-hydroxy-2-methylthioacetanilide (4) as well as that of the previously reported phenacetin metabolite 3-[(5-acetamido-2-hydroxyphenyl)thio]alanine (18) is described.

ISSN:0008-4042    

DOI:10.1139/v72-326

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

Mean relaxation times, Cole–Cole distribution parameters and apparent dipole moments, obtained from dielectric constant and loss measurements at 2 MHz and 1.5, 2.0, 2.5, 9.3, 16, 24, 35, 70, and 145 GHz, are reported for 1-, 2-, and 4-bromooctane, 1-bromodecane, 1-bromododecane, 1-bromohexadecane, 1-bromooctadecane, and 1,10-dibromodecane in cyclohexane solution at 25 °C.

ISSN:0008-4042    

DOI:10.1139/v72-327

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

Signs and magnitudes of long-range coupling constants in three phenylacetylene derivatives have been determined. Values of the coupling constants are discussed in terms of the McConnell formulation and compared with results of MO–INDO–FPT calculations. Coupling constants are dominated by π contributions. Estimated values of hyperfine interaction constants for acetylene and methylacetylene groups are respectively QCC≡CH = −12 and QCC≡CCH = +12 G. The theoretical calculations are in excellent agreement with experimental results. Both approaches allow quantitative estimation of nine bond couplings in 4-vinylphenylacetylene.

ISSN:0008-4042    

DOI:10.1139/v72-328

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

The e.p.r. spectrum of benzene on hydrogen mordenite (Zeolon H) has been studied as a function of coverage, degassing temperature, and hydrogen and oxygen treatment. The initial spectrum observed was that due to the benzene cation radical dimer. The maximum number of spins was formed when the solid was completely saturated with benzene. Large yields were obtained only when the zeolitic water and water of hydration of the protons were removed. The largest yields were observed where significant dehydroxylation had occurred. Chemisorbed oxygen was essential, and there was a 1:1.2 ratio between the maximum number of spins observed in the presence of excess oxygen and the amount of oxygen chemisorbed. The largest concentration of radical cations noted (2 × 1018/g) was much smaller than the number of acid sites known to be present (1021/g). In fact, only one unit cell of the hydrogen mordenite in 100 had a site capable of oxidizing benzene to the cation. Hence these sites must be in special positions in the solid.

ISSN:0008-4042    

DOI:10.1139/v72-329

出版商:NRC Research Press    

年代:1972

数据来源: NRC