2-Cyanobenzophenones were synthesized by reaction of 2-bromobenzophenones with copper(I) cyanide in DMF, and their transformations involving acid hydrolysis of the cyano group were studied. Reactions of o-benzoylbenzonitriles with trifluoroacetic acid in the presence or in the absence of sulfuric acid afforded 3-hydroxyphthalimidines in high yields. Under analogous conditions, benzonitriles having no acyl group in the ortho position were converted to the corresponding benzamides. 2-Cyanobenzophenones reacted with sulfuric acid in the absence of trifluoroacetic acid to give only substituted anthraquinones.

The reduction of 2-cyclopropylcarbonyl-, 2-(thiophen-2-yl)carbonyl-, and 2-arylcarbonylbenzonitriles with sodium tetrahydridoborate afforded 3-cyclopropyl-, 3-(2-thiophen-2-yl)-, and 3-arylphthalides, respectively, in high yields. Under analogous conditions, 3-cyanobenzophenones were converted to the corresponding 3-cyanobenzhydrols.

α-Alkyl-, α-arylalkyl-, and α-aryl-substituted benzyl alcohols were converted into the corresponding symmetrical dibenzyl ethers in the presence of a catalytic amount of 10% aqueous HCl both in methylene chloride and under solvent-free conditions. Analogous reactions in dioxane and on heating afforded mainly the corresponding arylalkenes, whereas symmetrical dibenzyl ethers were formed as minor products.

3-Unsubstituted 4,5-dihydroisoxazoles obtained by nitrosation of arylcyclopropanes are capable of undergoing efficient isomerization into 3-aryl-3-hydroxypropanenitriles during chromatography on alumina.

Benzyl alcohols formed by the reduction of benzaldehydes, alkyl aryl ketones, and benzophenones with sodium tetrahydridoborate in alcohols undergo in situ etherification with the solvent in the presence of a catalytic amount of HCl. Thus the process may be regarded as one-pot transformation of carbonyl compounds into the corresponding benzyl ethers. The yields of ethers depend on the substituent nature in the aromatic fragment of the initial carbonyl compound and on the alcohol used as reduction medium.

N -(2-Acylaryl)benzamides and analogous N -substituted furan-2-, thiophene-2-, and cyclopropane-carboxamides in the systems EtONa–EtOH, EtONa–THF, and t -BuOK– t -BuOH undergo Camps cyclization to 2-aryl-, 2-hetaryl-, and 2-cyclopropylquinolin-4(1 H )-ones with high yields. The same substrates in the system t -BuOK (5 equiv)–THF are converted mainly to the corresponding N -(2-hydroxyaryl) amides as a result of oxidative transformation of the acyl fragment into hydroxy group.

RATIONALE:Mass spectrometry is known as an excellent method to predict the behavior of organic compounds in solution. The behavior of organic compounds in the gas phase inside the ion source of a mass spectrometer allows their intrinsic properties to be defined, avoiding the influence of intermolecular interactions, counter ions and solvent effects.METHODS:Arylpyrrolidin-2-ones were obtained by condensed-phase synthesis from the corresponding N-arylcyclopropanecarboxamides. Electron ionization (EI) with accurate mass measurements by high-resolution time-of-flight mass-spectrometry and quantum chemical calculations were used to understand the behavior of the molecular radical cations of N-arylcyclopropanecarboxamides and N-arylpyrrolidin-2-ones in the ion source of a mass spectrometer. The geometries of the molecules, transition states, and intermediates were fully optimized using DFT-PBE calculations.RESULTS:Fragmentation schemes, ion structures, and possible mechanisms of primary isomerisation were proposed for isomeric N-arylcyclopropanecarboxamides and N-arylpyrrolidin-2-ones. Based on the fragmentation pattern of the N-arylcyclopropanecarboxamides, isomerisation of the original M+• ions into the M+• ions of the N-arylpyrrolidin-2-ones was shown to be only a minor process. In contrast, this cyclization proceeds easily in the condensed phase in the presence of Brønsted acids.CONCLUSIONS:Based on the experimental data and quantum chemical calculations the principal mechanism of decomposition of the molecular ions of N-arylcyclopropanecarboxamides involves their direct fragmentation without any rearrangements. An alternative mechanism is responsible for the isomerisation of a small portion of the higher energy molecular ions into the corresponding N-arylpyrrolidin-2-one ions. Copyright © 2016 John Wiley & Sons, Ltd.

Benzylic alcohols and diarylmethanols with electron-donating substituents in the aromatic ring reacted with aliphatic alcohols in the presence of a catalytic amount of HCl to give the corresponding alkyl arylmethyl ethers. The reactivity of diarylmethanols in the intermolecular dehydration depended on the nature of substituents in the aromatic rings and structure of aliphatic alcohol.

A method is proposed for synthesizing the dimer of 1,4-benzodiazepin-2-one with a cyclobutane-1,2-diyl linker. In this dimer, C5 atoms of monomeric heterocycles are bound to vicinal carbon of cyclobutane.

The action of equimolar amounts of nitrous acid formed in situ on benzylcyclopropanes with electron-donor and electron-withdrawing substituents in the aromatic part of the substrate lead, at certain temperatures, exclusively to the insertion of an N=O fragment into the three-membered carbocycle with subsequent formation of a heterocyclic isoxazoline (4,5-dihydroisoxazole) system.

Sovomercuration adducts of 2-nitrobenzyl-, 2-nitro-4,5-(ethylenedioxy)benzyl-, and 4,5-dimethoxy-2-nitrobenzylcyclopropanes were synthesized. The adducts reacted with sulfuric, fluorosulfonic, or chlorosulfonic acid to give 3-(2-chloromercurio)ethyl-1-oxo-3,4-dihydro-1 H -2,1-benzoxazinium ions whose stability depended on the nature of substituents in the aromatic ring. Unstable metalated 1-oxo-3,4-dihydro-1 H -2,1-benzoxazinium ions underwent fast protodemercuration to form metal-free 3-ethyl-1-oxo-3,4-dihydro-1 H -2,1-benzoxazinium ions. Stable analogs in the above acids did not change to an appreciable extent over a period of 48–72 h. Hydrolysis of stable metalated 1-oxo-1,3-dihydro-2,1-benzoxazolium ions afforded only 4-chloromercurio-1-(2-nitroaryl)butan-2-ol.

The reaction of trans-1,2,3-triphenylcyclopropane (I) with one equivalent of nitrous acid provides access to the expected isoxazoline (II).

Consecutive Michael addition and Knoevenagel intramolecular condensation reactions provide 3-alkoxymethyl-, 3-aminomethyl-, and 3-benzylquinolin-2-ones from o-(vinylcarbonylamino)acyl-benzenes. The synthesis of 3-alkoxymethylquinolin-2-ones may be carried out in a one-pot procedure directly from o-(vinylcarbonylamino)acylbenzenes. Aminomethylquinolin-2-ones are formed in one-pot approach only from corresponding o-(vinylcarbonylamino)benzophenones. Their analogs with o-alkyl-carbonyl groups form Michael adducts under these conditions.

3,4: 3′,4′-Bis(ethylenedioxy)biphenyl undergoes bromination, nitration, and cyclopropylcarbonylation only at the 2-position. Analogous reactions with 2-substituted bis(ethylenedioxy)biphenyls occur regioselectively at the 2′-position. The reactions of 2-cyclopropylcarbonyl- and 2,2′-bis(cyclopropylcarbonyl)bis(ethylenedioxy)biphenyls with complex metal hydrides afforded the corresponding arylcyclopropylcarbinols which tended to undergo intramolecular alkylation of the aromatic ring with conservation of the cyclopropane fragment (monosubstituted derivatives) and formation of cyclopropyl-containing cyclic ethers (disubstituted ethylenedioxybiphenyls). The reduction of the nitro group in 2′-cyclopropylcarbonyl-2-nitro-4,5: 4′,5′-bis(ethylenedioxy)biphenyl was accompanied by intramolecular cyclization involving spatially close functional groups, the cyclopropane fragment remaining intact.

The reaction of N-acylaminophenylcyclopropanes with HNO2 proceeds regioselectively with introduction of an N = O fragment into the three-membered ring and formation of the corresponding Δ2-isoxazolines. For ortho-substituted N-acylaminophenylcyclopropanes side processes were observed, caused by the intramolecular participation of the N-acyl group in conversions of the carbenium ions formed on opening the cyclopropane ring under the action of the nitrosating reagent, and by direct insertion of the modified ortho substituent into the three-membered ring.

The synthesis of 2-(N-R-amino)- and 2-(N-vinylcarbonylamino)acylbenzenes has been carried out and their heterocyclization into quinolin-2-ones under the action of sodium ethylate has been studied.

The reaction of benzylcyclopropanes to mercury (II) acetate in formic acid proceeds regioselectively and results in high yields of organomercuric compounds. It was shown that the formyloxy group in the homobenzyl position of 4-chloromercury-substituted arylbutanes is prone to easy solvolysis and nucleophilic substitution for bromine under the conditions of bromodemercuration.

AbstractThe reaction of trans‐1,2,3‐triphenylcyclopropane (I) with one equivalent of nitrous acid provides access to the expected isoxazoline (II).

The behavior of cyclopropyl phenyl sulfide and phenoxycyclopropane in the nitrosation reaction was studied. Cyclopropyl phenyl sulfide was found to convert quantitatively to cyclopropyl phenyl sulfoxide under the action of nitrous acid formed in situ. Under the same conditions, phenoxycyclopropane undergoes transformation to 5-phenoxyisoxasoIine (nitrophenols are formed as byproducts in this reaction).