摘要:

AbstractProtonated mesityl oxide (1,3,3‐trimethyl‐1‐hydroxyallyl cation,1) in strong acids has been found to give three reactions, resulting in a large variety of products depending on the acid used as the solvent.(1) Isomerization, followed by cyclization, gives the 2,5‐dimethyltetrahydrofuryl cation, which is about 5 × 103times stabler than1. The isomerization, which proceeds via intermediate dications, is acid‐catalysed; its rate decreases strongly in the order 1: 1 HF‐SbF5〉〉 9: 1 HF‐SbF5〉 1: 1 FSO3H‐SbF5〉〉〉 5: 1 FSO3H‐SbF5.(2) In FSO3H‐SbF5, dehydrogenation with subsequent ring closure to give the 2,4‐dihydrofuryl cation.(3) Cracking produces the acetyl cation and isobutene, which are formed by β‐scission ofC‐protonated mesityl oxide. The isobutene fragment reacts further to give, depending on the acid and the rate at which it is formed,t‐butyl cation, or the disulfonic acids of isobutene, or products thereof, and alkylcyclopentenyl ions.Rate constants of the three reactions in the different solvents have been measured. The 1‐ethyl‐3,3‐dimethyl‐1‐hydroxyallyl cation (2) reacts in a similar wa

ISSN:0165-0513    

DOI:10.1002/recl.19700890602

出版商:WILEY‐VCH Verlag    

年代:1970

数据来源: WILEY

摘要:

AbstractNMR evidence is presented for complex formation between nitromethane and sulfur trioxide in thrichlorofluoromethane as solvent according to . In addition, kinetic evidence for complex formation between nitrobenzene and sulfur trioxide in trichlorofluoromethane was obtained from sulfonation studies of that system.

ISSN:0165-0513    

DOI:10.1002/recl.19700890603

出版商:WILEY‐VCH Verlag    

年代:1970

数据来源: WILEY

摘要:

AbstractCompounds of the type H2CCR1‐CC‐CH2‐N(C2H5)2(I), when treated with potassiumtert‐butoxide in dimethyl sulfoxide are converted predominantly into the 3‐alken‐1‐ynylamines H3C‐CR1CH‐CC‐N(C2H5)2(IV), while those of the type R2CH2‐CR3CH‐CC‐CH2‐N(C2H5)2(VI) yield 1,3,5‐trienylamines R2CHCR3‐CHCH‐CHCH‐N(C2H5)2(VIII). A discussion of t

ISSN:0165-0513    

DOI:10.1002/recl.19700890604

出版商:WILEY‐VCH Verlag    

年代:1970

数据来源: WILEY

摘要:

Abstract5,6‐Dimethylazulene was prepared from 5,6‐dimethylindan by the diazoacetic ester method. Methyl 5,6‐dimethyl‐2‐indanylacetate was also obtained, and its structure determined from its 220 MHz NMR

ISSN:0165-0513    

DOI:10.1002/recl.19700890605

出版商:WILEY‐VCH Verlag    

年代:1970

数据来源: WILEY

摘要:

AbstractUnsaturated thiols having the system ‐C=C‐SH can be obtained by cleavage of the corresponding alkyl sulfides ‐C=C‐SR with alkali metals in liquid ammonia and acid hydrolysis after evaporation of the ammonia. Cycloalkanone dimethyl dithioacetals (CH2)nC(SCH3)2give cycloalkanethiols (CH2)nC(H)(SH) (n = 2, 4, 5, 6) on treatment with 4 equivalents of alkali metal. Alkyl cycloalkyl sulfides (CH2)nC(H)(SR) (R = CH3or C2H5) have been obtained by adding 2 equivalents of alkali metal to the dithioacetals (CH2)nC(SR)2. The cleavage reactions mentioned proceed with good to almost quantitative yields. The conversion of cycloalkyl ethyl sulfides and cycloalkanone diethyl dithioacetals with alkali metals is suitable for the preparation of the three‐ and six‐membered ring thiols but proceeds unsatisfactorily in the case of the five‐ and seven‐membered rings, cleavage between the ring and sulfur being th

ISSN:0165-0513    

DOI:10.1002/recl.19700890606

出版商:WILEY‐VCH Verlag    

年代:1970

数据来源: WILEY

摘要:

AbstractA number of compounds with general formula M2+(MPZ)n(anion)2is reported, in which M = Mn, Fe, Co, Ni, Cu, Zn and Cd; MPZ = 3(5)‐methylpyrazole, n = 2–7, and the anions are ClO4,−, BF4,−, NO3,−, CNS−, Cl−, Br−, I−.The compounds are characterized by chemical analyses, X‐ray powder diagrams, ligand‐field spectra, paramagnetic susceptibility and resonance measurements, and vibrational spectra.The ligand MPZ is found to coordinateviathe imino lone pair electrons, with the methyl group most probably located in the 5‐position,transto the coordinated metal ion.With respect to the same anion, groups of isomorphous compounds were found according to the X‐ray powder patterns. Ligand‐field spectra of the coloured transition‐metal ion complexes indicate that MPZ is a stronger coordinating ligand than the unsubstituted pyrazole. This is confirmed by the magnetic susceptibility measurements and the paramagnetic resonance spectra.Fairly regular octahedral groups M(MPZ)62+are found for the compounds with perchlorate and tetrafluoroborate anions (except for Cu2+), whereas strongly distorted tetragonal groups M(MPZ)4(anion)2are found for the compounds containing the other anions (and for the Cu2+compounds with BF4−and ClO4−anions). Infrared spectra of these latter compounds confirm the coordination of the ClO4,−, BF4−and NO3−anions,

ISSN:0165-0513    

DOI:10.1002/recl.19700890607

出版商:WILEY‐VCH Verlag    

年代:1970

数据来源: WILEY

摘要:

AbstractPreparation, properties and Raman spectra of the compounds SCl4· SO3, SeCl4· SO3, TeCl4· SO3and (CH3)4N · SO3Cl are described. These compounds are ionic in nature, possessing the positive ions N(CH3)4,+, SCl3,+, SeCl3,+and TeCl3+besides the common anion SO3Cl−.The frequencies of the SO3Cl−ion in these compounds are compared with our assignment1. The Raman spectra of TeCl4· GaCl3(TeCl3·+GaCl4−) and SCl4are

ISSN:0165-0513    

DOI:10.1002/recl.19700890608

出版商:WILEY‐VCH Verlag    

年代:1970

数据来源: WILEY

摘要:

AbstractIn this communication we introduce the viscosity‐temperature relation for liquids\documentclass{article}\pagestyle{empty}\begin{document}$$ \ln \,\,\eta = {\bf B}'' + {\bf A}''({\bf T} - {\bf C}'')^{ - 1} - {\bf D}''\,({\bf T} - {\bf T}_1)^2 $$\end{document}which actually contains four independent constants. The equation is applied to literature data for water, ethanol,n‐butyric acid, aluminium isopropoxide,n‐octane,n‐eicosane, toluene andn‐decylbenzene. The mean error between observed and calculated viscosity values for the entire liquid range varies from 0.06% forn‐octane to 0.8% for toluene.The equation is derived in an approximate way from the rate‐theory approach ofEyring, in which the liquids are assumed to have a quasi‐crystalline structure. We take into account a thermal expansion of the lattice, which influences the activation energy for viscous flow. The calculated values of the parameters are consistent with their physical meaning, with a possible exception for aluminium isopropoxide. The restrictions imposed by the theoretical mode

ISSN:0165-0513    

DOI:10.1002/recl.19700890609

出版商:WILEY‐VCH Verlag    

年代:1970

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19700890610

出版商:WILEY‐VCH Verlag    

年代:1970

数据来源: WILEY

摘要:

AbstractThe ring closure reaction of methyl 2,3‐bis(chloromethyl)thiophene‐5‐carboxylate with several primary amines gives a series of 5,6‐dihydro‐4H‐thieno‐[2,3‐c]pyrroles. Oxidation of some of these dihydro compounds, using aqueous hydrogen peroxide in methanol, furnishes the correspondingN‐oxides. When the nitrogen atom possesses an aromatic substituent and the oxidation is carried out with aqueous hydrogen peroxide in formic acid,Meisenheimer1rearrangement products instead ofN‐oxides are formed. The structure of one of the Meisenheimer products was elucidated by an independent synthesis of its degradation product.5H‐Thieno[2,3‐c]pyrroles are prepared by three separate methods: (a) dehydration of theN‐oxides; (b) autoxidation of the dihydrothieno[2,3‐c]‐pyrroles; (c) dehydrogenation of the dih

ISSN:0165-0513    

DOI:10.1002/recl.19700890611

出版商:WILEY‐VCH Verlag    

年代:1970

数据来源: WILEY