摘要:

AbstractThe rate of reaction of tri‐n‐propylbromogermane with propylene oxide has been measured under a variety of conditions. The effect on the reaction rate of temperature, concentration of reacting species, and the observed second‐order kinetics indicate a bimolecular type mechanism. The reaction offers a route to the synthesis of 2‐halo‐1‐hydroxy substitu

ISSN:0165-0513    

DOI:10.1002/recl.19640830902

出版商:WILEY‐VCH Verlag    

年代:1964

数据来源: WILEY

摘要:

AbstractPhotochlorinations of some alkanes (C5‐C7) and alkane carbochlorides (C3‐C6and C8) in the liquid phase have been investigated, in the absence and in the presence of benzene, a solvent enhancing the selectivity of the reagent.It was found that whereas the Cω‐1‐H bonds are the most reactive ones in nearly all photochlorinations, the Cω‐2‐H bonds are attacked preferentially when chlorinating octanoyl chloride and the alkanes C5

ISSN:0165-0513    

DOI:10.1002/recl.19640830903

出版商:WILEY‐VCH Verlag    

年代:1964

数据来源: WILEY

摘要:

AbstractTetrachloromuconic acid dehydrohalogenates spontaneously in an inert solvent to form either of two five‐membered lactone acids. In an alcoholic medium, however, there is the further loss of CO2with concurrent incorporation of a molecule of solvent to yield the novel neutral lactone, I

ISSN:0165-0513    

DOI:10.1002/recl.19640830904

出版商:WILEY‐VCH Verlag    

年代:1964

数据来源: WILEY

摘要:

AbstractThe pyrolysis of some acetates has been studied in the gas phase, at low concentrations, normal total pressure and in the temperature range 450‐650°K. Reaction rates, activation data and reaction products indicate that, for allyl‐acetate derivatives, the activated complex consists of an anti‐bonding electronical state involving a homolytic cleavage of the R‐OCOCH3bond. Linalyl acetate, neryl acetate and geranyl acetate particularly, are shown to have a common activated complex. As a consequence, the tertiary linalyl acetate will, upon heating, isomerise partly to the primary neryl and geranyl acetates in a 1,3 rearrangement

ISSN:0165-0513    

DOI:10.1002/recl.19640830905

出版商:WILEY‐VCH Verlag    

年代:1964

数据来源: WILEY

摘要:

AbstractThe preparation of the racemic mixtures of the 4 stereomers of 1‐methyl‐5‐(3′‐pyridyl)proline (nicotine‐2‐carboxylic acid) has been studied; one pathway, starting from ethyl nicotinate and proceedingvia6‐(3′‐pyridyl)‐2‐piper

ISSN:0165-0513    

DOI:10.1002/recl.19640830906

出版商:WILEY‐VCH Verlag    

年代:1964

数据来源: WILEY

摘要:

AbstractThe radical induced oxidation of acetaldehyde in the photo‐oxidation of azoethane was studied at 28°, 118° and 152°. In most experiments the acetaldehyde built up was substantially less than 0.8 mm, the observed limiting value at high conversion. Major products in the radical induced oxidation of acetaldehyde are carbon dioxide and methanol; minor products are carbon monoxide and (per)acetic acid. Formaldehyde was positively identified as a reaction product. It is proposed that the formation of the reaction products proceeds via the acetyl radical:CH3CHO + RCH2O· → CH3CO· + RCH2OH [8]CH3CO· → ·CH3+ CO [9]CH3CO· + O2→ CH3O· + CO2[11]CH3CO· + O2→ CH3CO3· [12]CH3CO3· + AH → CH3CO3H + A· [16]where AH stands for acetaldehyde and azoethane. The methoxy radicals will form methanol and formaldehyde.Reaction [11] does not necessarily proceed in one step. At 28°k9/k11=

ISSN:0165-0513    

DOI:10.1002/recl.19640830907

出版商:WILEY‐VCH Verlag    

年代:1964

数据来源: WILEY

摘要:

AbstractVapour‐phase bromination (375‐475°) as well as chlorination (350‐450°) of benzotrifluoride led to halogenobenzotrifluorides containing 53‐54%meta, 30‐32%paraand 13‐17%orthoisomers. Dihalogeno compounds were only formed to a small extent, except at high conversions. Liquid‐phase nitration of benzotrifluoride produced about 91%meta, 3%paraand 6%orthoisomer.Competitive chlorinations at 400° indicated that benzotrifluoride has about the same reactivity as benzonitrile, chloro‐ and fluoro‐benzene and is 3‐4 times less reactive than benzene.These and earlier dataPart VI:J. W. EngelsmaandE. C. Kooyman, Rec. Trav. Chim.80, 537 (1961. Parts VII and VIII of this series deal with liquid‐phase halogenations:E. C. KooymanandR. Louw, Rec. Trav. Chim.81, 365 (1962) and82, 616 (1963.can be accommodated by a mechanismE. C. Kooyman, Pure and Applied Chemistry7,193 (1963), (IUPAC Congress Lecture, London, July 1963.involving hydrogen‐loss as the isomer‐pattern determining step in gas‐phase halogenations of aromatic compounds, possibly through a posit

ISSN:0165-0513    

DOI:10.1002/recl.19640830908

出版商:WILEY‐VCH Verlag    

年代:1964

数据来源: WILEY

摘要:

AbstractChemical shifts of the ethylenic protons Hα and Hβ incisandtransβ‐arylthio‐,β‐arylsulfinyl‐ and β‐arylsulfonyl‐acrylic acids have been determined in acetone and in Na2CO3/D2O solution. The absorption signals were assigned unambiguously by β‐deuteration. An increase of electron‐withdrawing power of the β‐substituent (ArSO2>ArSO>ArS) causes an increase in shielding of Hβproton and a decrease in that of Hαproton. The τ‐values of the Hβprotons are lower in thetransthan in the correspondingcisacids, which may be explained in terms of magnetic anisotropy effects of the carboxyl group in thetransacids. Generally, the τ‐values of the Hβprotons are lower, and those of the Hαprotons higher, in acetone than in Na2CO3/D2O solution; this is probably due to differences in electron‐withdrawing power of the COOH and COO⊙ groups. In alltransderivatives the average values of the coupling constants Jαβare 15.3 c./sec., and lie between 10.1‐11.4 c./sec. for thecisderivatives. The effects ofpara‐substituents (CH3O, CH3, H, Cl, NO2) on the chemical shifts of the Hαand Hβprotons incisandtransβ‐arylthio‐, β‐arylsulfinyl‐, and β‐arylsulfon

ISSN:0165-0513    

DOI:10.1002/recl.19640830909

出版商:WILEY‐VCH Verlag    

年代:1964

数据来源: WILEY

摘要:

AbstractPaper‐chromatographic separation of ω‐phenylalkanoic acid anilides is discussed and compared with the separation of free acids by other methods. Combination of both separation methods affords a means of identification which has been designated aspseudo two‐dimensional chromatography.Preparation of the anilides and the ultra‐violet spectra of both acids and anilides are d

ISSN:0165-0513    

DOI:10.1002/recl.19640830910

出版商:WILEY‐VCH Verlag    

年代:1964

数据来源: WILEY

摘要:

AbstractThe accuracy of the double layer capacity measurements at high potentials described in part IX1is critically examined, especially with a view to the correct determination of the ohmic resistance of the cell. A limit for the exchange current density of the redox couple, which can be detected by the method of frequency variation, is determined. The systematic error in the calculated double layer capacity values, if this limit is just reached, is estimated. From impedance measurements in 0.1M‐HClO4solution it appears that the capacity‐potential curve is identical with that in 1M‐HClO4sol

ISSN:0165-0513    

DOI:10.1002/recl.19640830911

出版商:WILEY‐VCH Verlag    

年代:1964

数据来源: WILEY