Azulenes and related substances—XII A new azulene synthesis—guaiazulene and Se-Guaiazulene

The new method of azulene synthesis, described in the preceding communication, has been extended to the synthesis of guaiazulene and Se-guaiazulene.     

Polarography of non-benzenoid aromatic and related substances—VI Polarographic and spectrophotometric study of steric hindrance of coplanarity in 3-phenylsydnones

Substitution of alkyl groups on the ortho-position of 3-phenylsydnone causes a steric hindrance in coplanarity of the sydnone and phenyl rings. This was proved from the shift of the polarographic half-wave potentials (in excess of the polar effects), from the ultra-violet spectra, and from scale models. The behaviour of 3-o-tolylsydnone resembles more that of 3-benzylsydnone than that of 3-phenylsydnone. In 3′,4′-dihydroquinolino[1′,2′-c]-sydnone, the —CH₂ CH₂—bridge brings the sydnone and phenyl rings into a nearly coplanar position, shown on scale models, and its polarographic and spectrophotometric behaviour resembles that of 3-phenylsydnone.     

Azulenes and related substances—XV : Azuleno[2,1-a]azulene (part 1): reaction of 3,6,7,8-tetrahydrodibenzopentalene with diazomethane; synthesis of 11H-indeno[2,1-a]azulene

In an attempt to synthesise azuleno[2,1-a]azulene (1), Cu⁺ ion-catalysed reaction of diazomethane with 3,6,7,8-tetrahydrodibenzopentalene (4) has been investigated. Addition occurred to only one of the aromatic rings to give chiefly 1,2-benzo-4,5-cycloheptatrieno-3,6,7,8-tetrahydropentalene (13/14). Dehydrogenation of 13/14 to 11H-indeno[2.1-a]azulene has been carried out.     

Aminomethylating 9-methyl-3, 4- and 9-methyl-1, 2-benzoacridine

Aminomethylating 9-methyl-3, 4-benzoacridine with cycloalkylamine (pyrrolidine, piperidine, and morpholine) hydrochlorides in alcohol is described. The isomeric 9-methyl-1, 2-benzoacridine does notaminomethylate under similar conditions, apparently because the annulated benzene ring at positions 1, 2 in the acridine gives rise to steric hindrance, and the reaction product is 9--hydroxyethyl-1, 2-benzoacridine, converted by further heating to 9-vinyl-1, 2-benzoacridine.     

2-methyl-3-methylenecyclobutene-1-carbonitrile: A corrected structure and a new methylenecyclobutene monomer

The correct structure of the compound originally reported as 3-methylene[2.1.0]bicyclopentane-1-carbonitrile is 3-methylene-2-methylcyclobutene-1-carbonitrile. This new monomer undergoes free radical polymerization in the expected 1,5 manner.     

Amine-induced rearrangements of 2-bromo-1-(1H-indol-3-yl)-2-methyl-1-propanones: A new route to α-substituted indole-3-acetamides, β-substituted tryptamines, α-substituted indole-3-acetic acids and indole β-aminoketones

The reaction of 2-bromo-1-(1H-indol-3-yl)-2-methyl-1-propanone ( 1 ) and 2-bromo-1-(1-methyl-1H-indol-3-yl)-2-methyl-1-propanone ( 2 ) with primary amines proceeds in good yields to produce rearranged amides by a proposed pseudo-Favorskii mechanism. These amides in turn can either be reduced to produce β-substituted tryptamines or hydrolyzed to produce substituted indole-3-acetic acids. When the reaction is carried out using bulky primary or secondary amines, β-aminoketones are produced by elimination of hydrogen bromide followed by Michael addition. When hindered secondary amines or tertiary amines are used, elimination to the α,β-unsaturated ketones occurs.     

One-pot synthesis of 1-monosubstituted-1, 2, 3-triazoles from 2-methyl-3-butyn-2-ol

An efficient method for the synthesis of 1-monosubstituted-1, 2, 3-triazoles from 2-methyl-3-butyn-2-ol under copper catalyst conditions has been developed through a one-step one-pot sequence. This method provides a concise and efficient pathway to synthesize 1-monosubstituted-1, 2, 3-triazole derivatives in good to excellent yields.     

1,1,1-三氟-2-甲基-2-丙醇合成工艺研究

以氯甲烷(2)为原料制备甲基氯化镁格氏试剂;以三氯化镓为催化剂,甲基氯化镁与1,1,1-三氟丙酮(3)反应,经水解制得1,1,1-三氟-2-甲基-2-丙醇(1).产物结构经1 H-NMR、13 C-NMR、19 F-NMR及MS表征;通过单因素、正交实验和放大重复性实验确定了最佳反应条件:溶剂为正丁醚、格氏试剂浓度3 ...     

Gas-phase reactions of azulene with OH and NO3 radicals and O3 at 298 ± 2 K

Azulene, which is isomeric with naphthalene, was studied to determine whether it behaves like a polycyclic aromatic hydrocarbon or an alkene in its gas-phase reactions with OH and NO₃ radicals and O₃. Using relative rate methods, rate constants for the reactions of azulene with OH and NO₃ radicals and O₃ of (2.73 ± 0.56) × 10^?10 cm³ molecule^?1 s^?1, (3.9) × 10^?10 cm³ molecule^?1 s^?1, and <7 × 10^?17 cm³ molecule^?1 s^?1, respectively, were obtained at 298 ± 2 K. The observation that the NO₃ radical reaction did not involve NO₂ in the rate determining step indicates that azulene behaves more like an alkene than a polycyclic aromatic hydrocarbon in this reaction. No conclusive evidence for the formation of nitroazulene(s) from either the OH or NO₃ radical-initiated reaction of azulene (in the presence of NO_x) was obtained.     

Alkaline hydrolysis of 3-methyl-2H-1, 3-benzothiazinium iodides

Alkaline hydrolysis of the 3-methyl-2H-1, 3-benzothiazinium iodide 5a and of its 4-aryl derivatives 5b, c in the presence of hexacyanoferrate(III)ion resulted in the formation of 2, 2′-diaryloxodiphenyl disulfides 6a-c . In contrast, the 4-benzyl derivative 5d underwent hydrogen iodide elimination to give the enamine 7 . Mechanisms are proposed for the reactions.     

Proposed molecular structures for 3-butenenitrile, 2-methyl-3-butenenitrile,and 3-methyl-3-butenenitrile

Molecular structures are proposed for the two conformers, s-cis and gauche, existing for 3-butenenitrile and 3-methyl-3-butenenitrile, and for the three predicted conformers of 2-methyl-3-butenenitrile, using structural parameters transferred from related molecules. The proposed structures for the two conformers of 3-butenenitrile have principal moments of inertia which agree well with experimental values obtained by microwave spectroscopy, except for the gauche I_A moment. The experimental value of I_A for the gauche conformer of 3-butenenitrile could only be determined at the time with a low degree of precision, hence the microwave spectrum of this conformer should probably be reexamined.     

Beiträge zur Chemie der Si-N-Bindung,XI [1] polymere 1, 3-diaza-2-sila-cyclopentane

Linear polymers are built up by polycondensation of aminodimethylsilyl- or aminodiphenylsilyl-terminated monomeric or oligomeric 1,3-diaza-2-sila-cyclo-pentanes with bisphenols or disilanols. The thermal properties of the polymers are determined.