摘要:

The aldol condensation between 2,3-diphenyl-4-thiazolidinone and aromatic aldehydes, which cannot be effected by the usual catalysts used in the analogous reactions of 2-thiono-, 2-oxo-, and 2-imino-4-thiazolidinones, was achieved by the use of ethoxide ion. The structure of the 2,3-diphenyl-5-arylidene-4-thiazolidinone was confirmed by ultraviolet spectral data.

ISSN:0008-4042    

DOI:10.1139/v63-117

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

A novel and convenient method has been developed for the preparation of tris(hydroxy-methyl) phosphine oxide (THPO) from tetrakis (hydroxymethyl) phosphonium chloride (THPC). The method consists essentially of oxidative deformylation of THPC with lead carbonate inn-propyl alcohol. The reaction is facilitated by azeotropic distillation of di-n-propylformal andn-propyl alcohol.The reaction of THPC with lead carbonate as well as with lead oxide has been studied in detail in aqueous solution and inn-propyl alcohol. The reaction proceeds via the initial formation of tetrakis(hydroxymethyl) phosphonium hydroxide (THPOH) followed by deformylation to tris (hydroxymethyl) phosphine (THP). THP then undergoes oxidation by air as well as by lead carbonate or oxide to THPO. If air is bubbled through the mixture at elevated temperatures, atmospheric oxidation predominates with little or no oxidation by the lead compound.Depending upon the reaction conditions, a phosphonium hydroxide, a phosphine, or a phosphine oxide are products of the reaction of tetrakis(hydoxymethyl) phosphonium chloride with lead carbonate or oxide.

ISSN:0008-4042    

DOI:10.1139/v63-118

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

The photolysis of isocyanic acid vapor has been studied at temperatures ranging from −31 to 200 °C, and pressures from about 2 to 200 mm. Products identified were CO and N2in a ratio which varied from 2.5 to 5, together with much smaller amounts of hydrogen. The mechanismaccounts approximately for the products of the photolysis at low HNCO pressures and low temperatures. Additional reactions of NCO radicals with HNCO are postulated to account for increased production of CO and N2as the temperature and HNCO pressures were increased.The effects of adding ethylene and hydrogen to the system were briefly investigated. The results are explained in terms of reactions of NH and NCO radicals with hydrogen and ethylene.

ISSN:0008-4042    

DOI:10.1139/v63-119

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

The preparation of dehydroabietane-1-amine (II) has been achieved and characterized by base hydrolysis of the methyl carbamate (VII) via the following path: acid (I) → acid chloride (IV) → amide (V) → methyl carbamate (VII) → primary amine (II). The overall yield from acid (I) to amine (II) was approximately 50%. Other reactions leading to poor yields of the primary amine are discussed.

ISSN:0008-4042    

DOI:10.1139/v63-120

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

The kinetics of the pyrolysis ofn-butane have been studied at temperatures from 520° to 590 °C, and at pressures from 30 to 600 mm Hg; the rate was followed from pressure changes and by gas chromatography. The reaction was accurately of the three-halves order; the activation energy was found to be 59.9 kcal mole−1, and the frequency factor 3.24 × 1015cc1/2mole−1/2sec−1. The reaction is sensitive to surface; packing the vessel and 'conditioning' it usually led to a decrease in rate and an increase in activation energy. The reaction is concluded to be largely homogeneous, and to occur almost entirely by a free-radical mechanism; the initiation reaction is considered to be the dissociation of a butane molecule into two ethyl radicals, in its first-order region, and termination is believed to be the second-order combination of ethyl radicals. The mechanism proposed is shown to account satisfactorily for the observed behavior. The surface effect is attributed to a certain amount of initiation by abstraction, by a surface atom, of a hydrogen atom from butane, and to surface catalysis of the recombination of ethyl radicals.

ISSN:0008-4042    

DOI:10.1139/v63-121

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

The kinetics of the pyrolysis ofn-butane, when maximally inhibited by nitric oxide, were studied at temperatures from 540° to 610 °C, and at pressures from 30 to 550 mm Hg. The reaction has a short induction period and is accurately of the three-halves order; the activation energy was 65.9 kcal mole−1and the frequency factor 5.3 × 1016cc1/2mole−1/2sec−1. The reaction was somewhat less inhibited by surface than was the uninhibited reaction. Excess of carbon dioxide had no effect on the rate. The results are explained in terms of a free-radical mechanism for the maximally inhibited decomposition. It is proposed that the initiation step in the inhibited decomposition is mainly C4H10 + NO → C4H9 + HNO. This is followed by the ordinary chain-propagating reactions, and by processes such as C2H5 + NO → C2H5NO. The main chain-terminating step, of the type β + βNO, is concluded to be C2H5 + C2H5NO → C4H10 + NO or C2H6 + C2H4 + NO. This scheme leads to three-halves-order kinetics, and provides a satisfactory quantitative interpretation of the experimental behavior.

ISSN:0008-4042    

DOI:10.1139/v63-122

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

The nuclear magnetic resonance (n.m.r.) spectrum of 5-O-methyl-l,3-di-N-methyl-4,6-di-O-acetyldeoxystreptamine dihydrogenperchlorate requires the all-trans configuration since the signal for the equivalent ring hydrogens at the 4- and 6-positions is in the form of a triplet with a spacing of 10 c.p.s. This spacing requires these hydrogens to be axial and coupled with axial hydrogens at the neighboring 1-, 3-, and 5-positions.

ISSN:0008-4042    

DOI:10.1139/v63-123

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

Because the postulated non-planarity ofsym-tetramethylcyclobutanedione is based on a small value of electrical polarization, thecis- andtrans-2,2,4,4-tetramethylcyclobutane-1,3-diisocyanides have been prepared and stereospecifically rearranged to the analogous dicyanides. These substances show sufficiently large polarizations that the explanation of ring non-planarity is substantiated. Calculations in terms of the expected and observed dipole moments show that the ring deviates 20–30° from planarity. Although this non-planarity is not static, according to consideration of the cis geoisomers it would appear that one conformation is more prevalent than any others.

ISSN:0008-4042    

DOI:10.1139/v63-124

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

Silicon tetrafluoride and hydrazine react in a vacuum to produce a white, non-volatile, solid, 1:2 complex, SiF4.2N2H4. This compound sublimes with decomposition above 200° and is insoluble in common organic solvents. It reacts with (a) 55% hydrofluoric acid, (b) anhydrous hydrogen chloride, (c) ethylenediamine, (d) ammonia, and (e) boron trifluoride, producing: (a) (N2H5+)2SiF62−, (b) N2H5+Cl−, (c) SiF4.NH2(CH2)2NH2, (d) SiF4.2NH3, and (e) BF3.N2H4. A comparison of the infrared spectra of SiF4.2NH3, SiF4.2N2H4, and SiF4.NH2(CH2)2NH2suggests that all three complexes have cis octahedral structure.

ISSN:0008-4042    

DOI:10.1139/v63-125

出版商:NRC Research Press    

年代:1963

数据来源: NRC

摘要:

The nuclear magnetic resonance spectrum of strychnospermine has been measured at −20°, room temperature, and at +80°. The changes observed are attributed to restricted rotation in theN-acetyl group. At room temperature the rate of rotation is such that the band of one aromatic proton is extremely broad and therefore almost invisible. Double irradiation has been used to determine the environment of theC-methyl group of the alkaloid. The n.m.r. results confirm the structure previously postulated.

ISSN:0008-4042    

DOI:10.1139/v63-126

出版商:NRC Research Press    

年代:1963

数据来源: NRC