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The synthesis, TLC data and spectral characteristics of mercapturic acid methyl esters derived from five industrially important methacrylates and methacrylamide are described.

The electron ionisation spectra of bromine-containing derivatives of benzyl alcohol are often dominated by ions which do not contain bromine. We use the experimental data on a series of selected bromobenzyl alcohols to elucidate the easy loss of bromine atoms. In this process, arene-bonded bromines are displaced by hydrogens which originate from the benzyl group. Thus, we conclude that this reaction occurs during the “hydrogen ring-walk”. The suggested reaction mechanism and structures of intermediates, which can be considered, are discussed and graphically illustrated.

The condensation of 4-hydroxy-6-methyl-2H-pyran-2-one and substituted 2-hydroxybenzaldehydes with ammonium acetate gave the title heterocycles. Synthesis of 1,5-dihydro-2-methyl-4H-[1]naphtho-[1′,2′:5,6]pyrano[4,3-b]-pyridine-4,5-dione is also described. A reaction mechanism is discussed.

Reaction of deacetylvindoline (2) with excess thionyl chloride gave rise to hexacyclic 6,10-dichloro-6,17-epithio-11-methoxy-1-methyltabersonine (4) as a single product in 43.5% yield. The structure was deduced from 1H and 13C 1D and 2D NMR experiments as well as from mass spectra. A tentative mechanism of this complex transformation was also proposed.

Addition of excess ferrocenylacetylene (FcCCH) to [η 5 -(C 5 H 5 )Ti][μ:η 2 :η 2 -C 2 (SiMe 3 ) 2 ] 2 [η 5 -(C 5 H 5 )Mg] ( 1 ) affords the novel ferrocene–pseudotitanocene complex [η 5 -1,2,5,6-tetrakis(trimethylsilyl)-4-ferrocenylcyclohexa-1,4-dienyl](η 5 -cyclopentadienyl)titanium(II), [η 5 -(Me 3 Si) 4 FcC 6 H 2 ]Ti(η 5 -C 5 H 5 ) ( 2 ), as the sole isolated titanium-containing product. Its structure was established by EI MS, NMR and UV–vis spectroscopy. The formation of 2 follows the general reaction route of terminal acetylenes with 1 .

The complexes [(η5-C5Me4Ph)TiCl(μ-Cl)]2 (1) and [(η5-C5Bn5)TiCl(μ-Cl)]2 (2) (Bn = benzyl) were obtained by the reaction of TiCl3 and the corresponding alkali metal cyclopentadienides in a THF-toluene mixture. The X-ray diffraction single-crystal analysis revealed that both compounds form centrosymmetric dimers bridged via a pair of chloride ligands. Compound 1 crystallizes in the monoclinic space group P21/n (No. 14; a = 11.387(3) Å, b = 16.496(2) Å, c = 8.383(2) Å, β = 110.786(15)°, V = 1 472.2(6) Å3, Z = 2), and compound 2 in the monoclinic space group P21/c (No. 14; a = 18.967(5) Å, b = 10.7190(10) Å, c = 17.996(5) Å, β = 116.747(15)°, V = 3 267.2(13) Å3, Z = 2). Common features of the structures differ only negligibly. The Ti-Ti distance (in 1 3.3345(11) Å, in 2 3.374(2) Å) is considerably shorter than in paramagnetic dimeric titanocene monochlorides (3.91-3.95 Å). The compounds are diamagnetic, probably due to spin-paired d1 electrons.

Enantiomerically pure hydroxy thiol (S)-(+)- 6 , amino thiol (S)-(+)- 12 , and N , N -dimethylamino thiol (S)-(−)- 16 have been synthesized from BINOL (S)-(−)- 1 and the amino alcohol (S)-(−)- 7 , respectively, via the Newman-Kwart rearrangement of the corresponding thiocarbamoyl derivatives (S)-(−)- 2 , (S)-(−)- 10 , and (S)-(−)- 14 . Configurational stability of the binaphthyl unit has been observed.

Crystalline Ti(II) complexes [(C5H5-nMen)Ti(η2-Me3SiC≡CSiMe3)(μ-Cl)]2 (n = 3-5) (1-3) were prepared by reduction of the appropriate cyclopentadienyltitanium trichlorides (C5H5-nMen)TiCl3 in tetrahydrofuran by one equivalent of magnesium in the presence of at least one equivalent of bis(trimethylsilyl)acetylene. The X-ray structure analyses of 1-3 revealed that all compounds form chlorine-bridged centrosymmetric dimers.

The electrochemical oxidation of thiobenzanilide was studied in anhydrous acetonitrile as a model for the enzymatic oxidation of the substance. It has been found that a single electron is exchanged in the presence of 5 × 10−2 M HClO4 The oxidation products were identified as H2S, benzanilide, and 2-phenylbenzthiazole.

Attempts to carry out the hydroformylation of allyldiethylamine homogeneously catalyzed by rhodium complexes led to unexpected formation of N,N,N′,N′-tetraethyl-1,4-diaminobutane and 4-(diethylamino)-1-butanole as final products. The role of the catalyst on the product formation and the reaction mechanism are briefly discussed.

A mixture of isomeric (Me 4 C 5 H)(Me 3 C 5 (CH 2 )H)TiMe compounds was obtained by thermally induced methane elimination from (Me 4 C 5 H) 2 TiMe 2 at 130°C, analogous to the formation of (Me 5 C 5 )(Me 4 C 5 (CH 2 ))TiMe. The compound (Me 5 C 5 )(Me 3 C 5 (CH 2 ) 2 Ti was newly prepared in 27% yield by boiling a (Me 5 C 5 ) 2 TiCl 2 LiAlH 4 mixture in toluene, followed by sublimation of the soluble product. By an analogous process, (Me 4 C 5 H)(Me 2 C 5 (CH 2 ) 2 H)Ti was obtained in 10% yield. Neither type of complex was formed by either method from titanocene derivates with fewer methyl groups at cyclopentadienyl ligands.

From the underground part of Stylophorum lasiocarpum (OLIV.) FEDDE (0.58% alkaloids) (-)-stylopine and coptisine (as chloride IIa) were isolated as the principal alkaloids. Smaller quantities of sanguinarine, macarpine, chelerythrine, chelirubine, chelilutine (as the respective chlorides IIIa, IIIb, IIIc, IIId, IIIe) protopine, corysamine (as chloride IIb), berberine (as chloride IIc) and (-)-trans-N-methylstylopinium hydroxide (as iodide IVa) were also isolated. Chromatographically were detected small amounts of chelidonine, allocryptopine, cryptopine, scoulerine, isoboldine, magnoflorine and salt of cis-N-methylstylopinium. The aerial part (0.16% alkaloids) afforded (-)-stylopine, coptisine and (+)-chelidonine as dominant alkaloids and small amounts of protopine and (-)-cis-N-methylstylopinium hydroxide (as iodide IVb).Chromatography proved negligible amounts of sanguinarine, chelirubine, cryptopine, scoulerine, isoboldine, corytuberine, corysamine, berberine, magnoflorine and trans-N-methylstylopinium iodide. The so far undescribed 8-methoxydihydromacarpine (VIb) was prepared.

The homogeneously catalyzed carbonylation of N -alkylallylamines to N -alkyl-2-pyrrolidones has been studied and the effects of reaction variables have been evaluated. Contrary to expectations, the reaction proceeded at milder conditions with a CO/H 2 1:1 mixture than with pure carbon monoxide, and with phosphine-free rhodium complexes than in the presence of phosphines, which enhanced simultaneous double-bond hydroformylation. Studies of the reaction of Rh(I) complexes with amines indicate that the carbonylation proceeds via Rh(0) clusters.

A four step synthesis of n-butyl (3-{sup 13}C)acrylate from ({sup 13}C)methyl iodide is described. The procedure involves methylation of butyl acetoacetate, subsequent bromination, alkaline cleavage and, finally, dehydrobromination using cyclohexyldimethylamine. The overall yield was 5%. (author).

A method is presented for the determination of relative electron impact ionization cross-sections for polar and less volatile compounds. The compound is generated in the gas phase by flash-vacuum pyrolysis of a norbornene precursor, whereby the cyclopentadiene co-formed in a stoichiometric amount serves as internal standard. Cross-sections of 31 oxygenated C (4) molecules have been measured and tested for correlation with several molecular and bulk parameters

Corner Attack on Cyclopropane by Thallium(III) Ions : A Highly Stereospecific Cleavage and Skeletal Rearrangement of 3a,5‑Cyclo‑5a‑cholestan‑6a‑ol

The FeCl3-mediated, heterogeneous cross-coupling of the title compounds (1 + 2 → 3) has been re-examined and formation of the molecular crystal (1 + 2) shown to be irrelevant to the selectivity observed; a comparison of FeIII and CuII as reagents is presented.

The cleavage of the fused-ring cyclopropane hydroxy derivative 1 by means of HgII is highly stereoselective and gives a rearranged organomercurial 3, transmetallation of which with PdII can be controlled by ligands to afford either lactol 4 or acid 8; the latter compound is formed via an intramolecular insertion of Pd into the C–H bond (6→7), as evidenced by isotopic labelling.

Oxidative coupling of a 1:1 mixture of 2-naphthol (1) and 2-naphthylamine (2) by means of copper(II) chloride in the presence of benzylamine gives the cross-coupled product 3 (2-amino-2′-hydroxy-1,1′-binaphthyl) in 68% yield while copper(II) chloride itself yields mainly the homo-coupled diamine 4 (2,2′-diamino-1,1′-binaphthyl) in 33% yield. Pure 4 was prepared by oxidation of 2-naphthylamine (2) using (PhCH2NH2)4CUCl2 in 58% yield.

The Schiff bases of benzaldehyde and aliphatic amines form immonium ions on electron-impact, which rearrange and eliminate hydrogen cyanide in a different way than the corresponding derivatives of pyridine-2-aldehyde. The presence of at least one hydrogen on the α-carbon atom in the amine moiety is a necessary condition for this rearrangement. A mechanism is suggested for this process.

Ionized (E)- and (Z)-prop-1-en-1-ols, [CH3CHCHOH]+·, were generated by electronimpact ionization of the unstable enols and by dissociative ionization of 3-methylnorborn-5-en-2-ols. The loss of hydrogen from molecular ions decomposing in the ion source takes place from C-1, C-2 and C-3 positions in a nearly random manner, as determined by deuterium labelling. This is due to reversible isomerization of [CH3CHCHOH]+· to [CH2CHCH2OH]+· and [d CH 2 CH 2 C dHOH]+· prior to decomposition. The appearance energy for the hydrogen loss was determined as AE([C3H5O]+) = 10.63 ± 0.06 eV, which sets the energy of the transition state at 854 kJ mol−1. Low-energy [CH3CHCHOH]+· decomposes mainly to CH3CH2CO+, while at higher internal energies the formation of CH2CHCHOH+ is preferred. [C2H5]+ and [CHO]+ ions arise mainly as secondary fragments with Ae([C2H5]+) = 12.50 ± 0.10 eV andAE([CHO]+) = 12.95 ± 0.15 eV.

The catalytic system Et 2 AlCl/TiCl 4 induces Diels-Alder cycloaddition of bis(trimethylsilyl)acetylene to 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene and ( E )-1,3-pentadiene affording 1,2-bis(trimethylsuyl)cyclohexa-1,4-dienes in high yields. The cyclohexadienes are readily converted to the corresponding 1,2-bis(trimethylsilyl)benzenes upon heating to 240°C. Mass, infrared, 1 H, 13 C and 29 Si NMR spectra of all the products obtained are reported and briefly discussed. The crowded character of aromatic compounds is reflected in their mass, 13 C and 29 Si NMR spectra.

Titanocene hydride derivatives induce the cyclization of 1,2-divinylcyclohexanes to trans- and cis-1-methylene-octahydro-1H-indene and their isomerization to trans- and cis-3-methyl-3a,4,5,6,7,7a-hexahydro-1H-indene.

The internal cyclisation of 1,5,9-cyclododecatriene, induced by a catalytical amount of Cp 2 TiCl 2 -LAHδ, leads to a mixture of cis , anti , cis -tricyclo[7.3.0.0 2,6 ]-7-dodecene ( 1 ), cis , syn , trans -tricyclo[7.3.0.0 2,6 ]-7-dodecene ( 2 ), trans , syn -tricyelop[7.3.0.0 2,6 ]-6-dodecene ( 3 ) and 5,6,7,8,9,10-hexahydrobenzocyclooctene ( 4 ). The structures of the main products were determined from the spectra of a number of derivatives taking into account symmetry properties and configurational flexibility.

The title reaction yields (3R,5R) and (3R,5S) isomers of methyl 5-cyanotetrahydro-1,4-2H-thiazine-3-carboxylate, together with methyl 2-acetylthiazole-4-carboxylate as a minor by-product. The stereochemistry of the tetrahydrothiazine derivatives is discussed.

Titanium - catalyzed dimerization of cycloheptatriene affords pentacyclo[7.5.0.02,8.05,14.07,11]tetradeca-3,12-diene, 3 , and pentacyclo[8.4.0.03,7.04,14.06,11]tetradeca-8,12-diene, 4 . By heating, 3 is converted quantitatively into 4 .

Mass spectrometric measurement of the pyrolyzed (790-1 030 K) mixture of 1,5-hexadiene or 2,5-dimethyl-1,5-hexadiene with dioxygen afforded no evidence for the presence of allylic peroxyl radicals or aldehydes in the gas phase though the allylic radicals were readily detected at low ionization potentials. On the other side, the electron spin resonance measurement revealed that the allylic radicals were converted quantitatively to allylic peroxyl radicals during condensation of pyrolytic mixtures at 77 K, and acrolein and methacrolein were found mass spectrometrically after thawing of the condensed pyrolytic material as stable products of the allylperoxyl and 2-methylallylperoxyl radical, respectively. These results are compatible with the temperature dependent dissociation equilibrium of the allylic peroxyl radicals. The allylic peroxyl radicals were trapped at 77 K using co-condensation with adamantane from the gas phase in yields as high as 30-50% of the radicals produced in pyrolysis. The electron spin resonance spectra showed partial motional freedom of the peroxyl radicals when they were trapped in the low-contaminated adamantane matrix at 77 K, but in matrices highly contaminated with the biallyl hydrocarbon and products of pyrolysis the ESR spectra indicated rigidly trapped peroxyl radicals. Free rotation of the allylic peroxyl radicals in both types of matrices occurred at 110 K.

The CP ★ 2 TiAlH 4 complexes (CP ★  Cp, MeCp, Me 3 Cp, Me 4 Cp, Me 5 Cp and EtMe 4 Cp) were prepared from CP ★ 2 TiCl and LiAlH 4 in toluene. On aging, all the CP ★ 2 TiAlH 4 complexes, except for the peralkylated ones, formed paramagnetic clusters composed probably of the CP ★ 2 TiH and CP ★ 2 TiAlH 4 units. The clusters reacted with an excess of butadiene to give (1-methyl-η 3 -allyl)titanocenes and CP ★ 2 TiAlH 4 complexes. The CP ★ 2 TiAlH 4 complexes yielded the same allyltitanocene products, but in a slower subsequent reaction. Aging of the peralkylated CP ★ 2 TiAlH 4 complexes led to the thus far unknown paramagnetic products which are unreactive to butadiene. The (1-methyl-η 3 -allyl)titanocenes were also prepared from CP ★ 2 TiCl by reaction with LiAlH 4 in the toluene/butadiene mixture. The CP ★ 2 TiAlH 4 1 complexes which formed transiently in these systems were found to have ESR parameters different from those obtained in pure toluene. The effects were established of themethyl substituents in the CP ★ ligands on the ESR and electronic absorption spectra of the CP ★ 2 TiAlH 4 complexes and (1-methyl-η 3 -allyl)titanocenes.

Condensations of 4-(2-hydroxyphenyl)but-3-2-one with methyl acetoacetate, pentane-2,4-dione, dimedone, and methyl cyanoacetate under the conditions of the Hantzsch synthesis lead to 9-methyl-8-oxa-10-azatricyclo[7.3.1.02,7]trideca-2,4,6,11-tetraene derivatives and related heterocycles. An analogous condensation with 2-aminopropene-1,1,3-triscarbonitrile yields stereoselectively 11-dicyanomethylene-9-methyl-8-oxa-10-azatricyclo[7.3.1.02,7]trideca-2,4,6-triene-12α-carbonitrile. Under suitable reaction conditions, the condensation of 4-(2-hydroxyphenyl)but-3-en-2-one with cyanamide affords various products with the 9-methyl-8-oxa-10,12-diazatricyclo[7.3.1.02,7]trideca-2,4,6,11-tetraene skeleton. Condensation products of salicylaldehyde with acetone, 2-aminopropene-1,1,3-triscarbonitrile, and 3-aminocrotononitrile have been identified.

The loss of histidine and the formation of additional by-products during the purification and storage of [14C(U)]-L-histidine preparations on chromatographic carriers was followed. The product formed mainly on chromatographic paper was identified as the condensation product of histidine with formaldehyde; on thin layer of silica gel mainly degradation products of histidine were obtained. Possibilities to decrease the formation of these undesirable by-products were discussed.

μ-(η5 : η5-Fulvalene)-di-μ-hydrido-bis(η5-cyclopentadienyltitanium) and μ-(η5 : η5-fulvalene)-μ-chloro-μ-hydrido-bis(cyclopentadienyltitanium) form a thermally stable complex which catalyzes the intermolecular hydrogen transfer in unsaturated hydrocarbons, in addition to isomerizations and cyclizations. Cyclic hydrocarbons disproportionate under catalysis to saturated and aromatic hydrocarbons, while linear olefins yield predominantly linear alkanes and high molecular weight tar. The catalyst enables the hydrocarbon system to approach the thermodynamic equilibrium through a series of substitution reactions between alkyl- and allyltitanocene-like species and olefins and dienes. The catalytic complex was characterized by UV and ESR spectra. About one half of overall titanium content could be converted to mononuclear η3-allyltitanocene-like species, stable up to 400 °C. This exceptional thermal stability is ascribed to a firmly bound allyl containing ligand.

The McLafferty rearrangement for 2,5-diphenyl-1-hexene and its deuterium labelled analogues has been investigated. The α-methylstyrene fragments originating from different parts of the molecular ion retain the charge with equal probability and afford identical metastable spectra. The geometry of the transition state is discussed.

The alkaloidal composition in the two title taxa differs only quantitatively. Both contain amurine as the main alkaloid. P. nudicaule ssp. xanthopetalum contains muramine, protopine and alkaloid PN1 (probably identical with (±)-nudaurine (Ia)) as dominant alkaloids; further were isolated amurensine, epialpinine, cryptopine, mecambridine and alpinigenine. Allocryptopine, papaverrubines A, B, D and G, palmatine and coptisine were detected chromatographically. The quaternary alkaloid fraction afforded cis-N-methylstylopinium hydroxide (as the iodide II) which was isolated for the first time from P. nudicaule. In P. nudicaule ssp. album the alkaloid PN1, epialpinine, amurensine and muramine represented the dominant alkaloids, accompanied with mecambridine, protopine, cryptopine, allocryptopine and alpinigenine. Among the quaternary alkaloids N-methylstylopinium hydroxide was found.

The mass spectra of four of the six 1,4-dihydroxy- Δ6,7-octalins are reported. The spectra differ considerably, depending on the configuration of the hydroxyl groups. The relative amounts of 1-3,1-4, transannular 1-3 and hydroxyl-hydroxyl elimination of water from the molecular ions were determined by using specificaliy labelled compounds. Effects of configuration and conformation are discussed.

The addition of dienes to the system [(Cp2TiCl)2] ∶ LiAlH4∶toluene changes the system so that the complex [Cp2TiAlH4] is quantitatively formed instead of a titanocene hydride — aluminium hydride cluster. The complex [Cp2TiAlH4] is further converted into η3-allyltitanocene derivatives ([Cp2TiA]) if the diene structure is suitable for formation of stable [Cp2TiA] compounds and if the equilibrium [Cp2TiAlH4]+diene⇌[Cp2TiA]+A1H3 is shifted towards the formation of [Cp2TiA] by the excess of diene. All the compounds [Cp2TiA] exhibit high-resolution e.s.r. spectra at g=1.993, showing interaction of the unpaired electron with the cyclopentadienyl and η3-allyl protons. The e.s.r. spectra clearly reveal the presence of alkyl substituents atsyn-1,3-positions of η3-allyl ligand, and show a triplet of multiplets for (η3-allyl)titanocene, doublets of multiplets for (1-alkyl-η3-allyl)titanocenes and single multiplets for (1,3-dialkyl-η3-allyl)-titanocenes. thermal isomerization of (1,3-dimethyl-η3-allyl)-titanocene and (1-methyl-3-ethyl-η3-allyl)titanocene, hitherto considered as the stable Cp2TiA compounds, into (1-alkyl-η3-allyl)titanocenes was confirmed by e.s.r. and electronic absorption spectroscopy as well as by chemical means.

Unstable 2-hydroxpropene was prepared by retro-Diels-Alder decomposition of 5-exo-methyl-5-norbornenol at 800°C/2 × 10−6 Torr. The ionization energy of 2-hydroxypropene was measured as 8.67±0.05 eV. Formation of [C2H3O]+ and [CH3]+ ions originating from different parts of the parent ion was examined by means of 13C and deuterium labelling. Threshold-energy [H2CC(OH)CH3]+˙ ions decompose to CH3CO++CH3˙ with appearance energy AE(CH3CO+) = 11.03 ± 0.03 eV. Higher energy ions also form CH2COH+ + CH3 with appearance energy AE(CH2COH+) = 12.2–12.3 eV. The fragmentation competes with hydrogen migration between C(1) and C(3) in the parent ion. [C2H3O]+ ions containing the original methyl group and [CH3]+ ions incorporating the former methylene and the hydroxyl hydrogen atom are formed preferentially, compared with their corresponding counterparts. This behaviour is due to rate-determining isomerization [H2CC(OH)CH3]+˙ [CH3COCH3]+˙, followed by asymmetrical fragmentation of the latter ions. Effects of internal energy and isotope substitution are discussed.

Ethenol, 1-d-ethenol, O-d-ethenol and Z-2-d-ethenol were prepared by pyrolysis of corresponding 5-norbornenols at 800°C/2 × 10−6 Torr. The most important fragments in the electron impact mass spectrum of ethenol are [C2H3O]+ and CHO+ and CH3˙. The hydrogen atom eliminated from the molecular ion comes mainly from the hydroxyl group (68%) and to a lesser extent from C(1) (25%) and C(2) (7%). The loss of the hydroxyl hydrogen is preceded by rate-determining migration of the hydrogen atom from C(1) onto C(2) to yield CH3COH+˙ions that decompose to CH3CO+ and H˙. The loss of deuterium from O-d-ethenol shows a very small primary isotope effect (kH/kD=1.07), whereas a significant effect is observed for the loss of hydrogen from 1-d-ethenol (kH/kD=1.28). The appearance energy of [C2H2DO]+ from 1-d-ethenol, AE=11.32 eV, gives a critical energy for the hydrogen loss, E=203 kJ mol−1, which is 90 kJ mol−1 above the thermochemical threshold for CH3CO++H˙. The appearance energy of CDO+ from 1-d-ethenol was measured as 12.96±0.07 eV, which sets the barrier to isomerization to CH3CDO+˙ at 1121 kJ mol−1. The ionization energy of ethenol was found to be 9.22±0.03 eV.

The Hantzsch condensation of salicylaldehyde with ethyl acetoacetate and ammonia has been re-examined. The reaction leads primarily to a 1,4-dihydropyridine intermediate which, after isomerization, undergoes a ring closure to give a bridged 1,4,5,6-tetrahydropyridine product, or is oxidized to 4-methyl-2-(2-oxo-2H-1-benzopyran-3-yl)[1]benzopyrano[3,4-c]pyridin-5-one. Bridged tetrahydropyridines with the 8-oxa-10-azatricyclo[7.3.1.02,7]trideca-2,4,6,11-tetraene skeleton were found in the Hantzsch-type condensation of salicylaldehyde with malononitrile, ammonium acetate, and acetone or butan-2-one. A mechanism for these reactions is discussed.

The reaction of N-phenyl-1,4-benzoquinoneimine (I)1 and 4-hydroxydiphenylamine (II) with the carbon centred 1-cyano-1-methylethyl radical (R·) was studied in connection with an investigation of the action mechanism of industrial antidegradants, such as N-phenyl-N′-sec-alkyl-1,4-phenylenediamines. The mixture of I and II reacts very readily with R·, giving rise to III, VI, and VIII. I alone reacts much slowlier, and the reaction mixture contains more products. IV and VII were identified along with III. Under the conditions used, II alone does not react at all. IV exists in two isomeric forms, syn and anti. VIII is very labile; XI was isolated from its transformation products. Reduction of IV gives V, which is labile, similarly to VIII. Im Zusammenhang mit dem Studium des Wirkungsmechanismus von industriell hergestellten Antidegradantien vom Typus der N-Phenyl-N′-sek-alkyl-1,Cphenylendiamine wurde die Reaktion von N-Phenyl-1,4-benzochinonimin (I) und 4-Hydroxydiphenylamin (II) mit dem Kohlenstoff-Radikal 1-Cyano-l-methylethyl (R·) studiert. Das Gemisch von I und II reagiert mit R· sehr leicht unter Bildung der Verbindungen III, VI und VIII. I allein reagiert wesentlich langsamer, und das Reaktionsgemisch enthalt mehrere Produkte. Neben der Verbindung III wurden auch die Verbindungen IV und VII identifiziert. II allein reagiert bei denselben Bedingungen nicht. Die Verbindung IV bildet die zwei isomeren Strukturen syn und anti. Die Verbindung VIII ist ziemlich unbestandig; aus ihren Umwandlungsprodukten wurde XI isoliert. Bei der Reduktion von IV entsteht die Verbindung V, die ahnlich wie VIII unbestandig ist.