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Showing papers on "Cyclopropane published in 1982"


Patent
22 Jun 1982
TL;DR: In this article, new derivatives of 1-aryl 2-aminomethyl cyclopropane carboxamides (Z) of general formula I: ##STR1## in which: R represents a hydrogen or halogen atom, a lower alkyl group, lower alkoxy group, or a hydroxy.
Abstract: The present invention concerns new derivatives of 1-aryl 2-aminomethyl cyclopropane carboxamides (Z) of general formula I: ##STR1## in which: R represents a hydrogen or halogen atom, a lower alkyl group, a lower alkoxy group, or a hydroxy. nitro or amino group; n represents the value 1 or 2; R 1 and R 2 represent a hydrogen atom, a lower alkyl group, an aryl or lower alkaryl group, possibly substituted, preferably in para position, by a halogen atom, preferably a chlorine atom; R 1 and R 2 may also form a heterocycle having 5 or 6 members with the adjacent nitrogen atom; R 3 and R 4 represent a hydrogen atom or a lower alkyl group; R 3 and R 4 may also form with the adjacent nitrogen atom a heterocycle having 5 or 6 members, possibly containing an additional heteroatom selected from among nitrogen and oxygen, as well as their salts with therapeutically acceptable inorganic or organic acids, and their pharmaceutical compositions and use in the treatment of central nervous system disturbances, e.g., depression.

62 citations


Journal ArticleDOI
TL;DR: The dienylcyclopropanes smoothly rearrange of five-membered rings in the presence of a Pd(O) catalyst under mild conditions as mentioned in this paper, which is the case for all the dienelcyclopropanes.

60 citations




Journal ArticleDOI
TL;DR: In this article, an equilibrium mixture of gauche and cis conformers for (bromomethyl)cyclopropane and epibromohydrin has been found for the Raman spectra.
Abstract: Infrared and Raman spectra of (bromomethyl)cyclopropane and epibromohydrin have been recorded. Reversible spectral changes which accompany changes in temperature indicate the existence of an equilibrium mixture of gauche and cis conformers for (bromomethyl)cyclopropane. The gauche form is more stable, and from the variable temperature studies an enthalpy difference of 2.0±0.2 kcal mol−1 has been obtained for the liquid phase. For epibromohydrin, two non-equivalent gauche conformers have been identified, and the gauche-1 form is more stable than the gauche-2 by 0.80±0.20 kcal mol−1 in the liquid phase. Additionally there is evidence for a third conformer, presumably the cis form, but characterization of this conformer has been limited by the complexity of the spectra associated with the gauche-1 and gauche-2 forms. Consequently, only a lower limit can be given for the ΔH separating the cis and gauche-1 conformers. The results are consistent with previous observations for similar molecules.

38 citations


Journal ArticleDOI
TL;DR: In this article, a rationale for this unusually mild nucleophilic cyclopropane ring opening is discussed, and the 4β-X-ethyl derivatives of 3,5-dimethyl pyrazoles and -isoxazoles are discussed.

37 citations


Journal ArticleDOI
TL;DR: In this article, a thermochemical cycle is used to estimate the gas phase acidity of several hydrocarbon radical cations: pKa, methane, ethane, propene, benzene, and toluene.
Abstract: A thermochemical cycle is used to estimate the gas phase acidity of several hydrocarbon radical cations: hydrocarbon radical cation (pKa), methane (≥ 86.5 ± 1), ethane(101 ± 1, 102 + 1), ethylene (≥ 125 ± 2), acetylene (118 ± 3, 122 ± 1), propene(124 ± 1, 122 ± 1), cyclopropane (≥ 134, ≥ 131), benzene (147 ± 1), and toluene (139 ± 1, 140). Similarly, proton affinities of the conjugate base, the hydrocarbon radical, are estimated.An estimate of the proton affinity is obtained using abinitio MO calculations. A Hartree–Fock proton affinity, PAHF(R•)g is defined as the difference in the computed energies of a radical cation and its conjugate base at the Hartree–Fock level. Calculations at the SCF level are carried out using both the minimal (STO-3G) and extended basis sets, without (3-21G, 4-31G, and 6-31G) and with (4-31G* and 6-31G*) polarization functions on carbon.The agreement between the thermochemical and abinitio estimates of the proton affinity is satisfactory.

29 citations


Journal ArticleDOI
TL;DR: In this article, the presence of an NO 2 substituent is found to eliminate the negative electrostatic potentials associated with the "bent" CC bonds cyclopropane.

28 citations



Journal ArticleDOI
TL;DR: In this article, structural data relating to 369 organic derivatives of C2X(X=C, N, O, Si, P, S) and CXY(X, Y=N, O) heterocycles have been retrieved from the Cambridge Crystallogrphic Database and analysed in conjuction with pertinent gas-phase results.

24 citations



Journal ArticleDOI
TL;DR: In this paper, the orientation and symmetry of cyclopropane adsorbed at 95 K on Ru(001) at and below saturation surface coverage were determined by combining in situ high-resolution electron energy loss spectroscopy (EELS) and angular resolved UV-photoelectron spectrograph (ARUPS).
Abstract: In order to determine the orientation and symmetry of cyclopropane adsorbed at 95 K on Ru(001) at and below saturation surface coverage, we have combined in situ high resolution electron energy loss spectroscopy (EELS) and angular resolved UV‐photoelectron spectroscopy (ARUPS). Both the vibrational and the photoelectron spectra show that the molecule adsorbs associatively with neither an opening of the carbon ring nor an abstraction of hydrogen atoms from the ring. The dipole activity of the ring modes ν10(1010 cm−1) and ν11 (880 cm−1) in EELS and the polar angular distribution in photoemission of the 1a2\, 3a1′, and 1e\ molecular orbitals suggest Cs (σv) symmetry of the admolecule. This type of reduced symmetry can result from an orientation of the molecule in which one C–C bond, but not the entire carbon ring, is parallel to the surface. Both the orientation and the symmetry of the admolecule are discussed in relation to a tentative bonding picture assuming a weak interaction between the delocalized ’’e...

Journal ArticleDOI
TL;DR: In this article, the smallest one-bond carbon-carbon coupling constants of cyclopropane derivatives have been measured for [1-13C]cyclopropane-1,1-dicarboxylic acid and cycloparnecarboxyl acid.
Abstract: The smallest one-bond carbon—carbon coupling constants of cyclopropane derivatives have been measured for [1-13C]cyclopropane-1,1-dicarboxylic acid and cyclopropanecarboxylic acid. The 13C, 13C coupling constants of cyclopropylcarbinol have also been determined. The dependence of 1J(CC) of the three-membered ring on different substituents and hybridization effects is evaluated. The carbon—carbon coupling constant of the unsubstituted cyclopropane is discussed on the basis of self-consistent perturbation theory (SCPT) and s character calculations (localized bond orbitals), and the results are compared with the experimental finding. It is shown that the 1J (CC) can be interpreted by assuming a dual-pathway coupling mechanism.

Journal ArticleDOI
TL;DR: The mechanism of formation of monodeuterated cyclopropane fatty acids on administration of L-methione-methyl-d3 to L. plantarum has been investigated in this paper.
Abstract: The mechanism of formation of monodeuterated cyclopropane fatty acids on administration of L-methione-methyl-d3 to L. plantarum has been investigated. It has been found that the extent of exchange is not affected by the presence of oxygen in the medium, that neither formate-d0 nor formaldehyde-d2 is significantly incorporated into the fatty acid, and that methionine reisolated from the intracellular pool does not contain any exchanged species. These experiments militate against any mechanism involving exchange prior to methyl group transfer. Parallel feeding experiments using methionine labelled in the methyl group with one, two, or three deuterium atoms were carried out and in this way that extent of exchange was quantitated. It was found that at least one-third of the cyclopropane fatty acid from methionine methyl-d3 experiments is derived from an exchanged methyl group. The intramolecular and intermolecular primary deuterium isotope effects for biological cyclopropane ring formation were measured and f...

Patent
06 May 1982
TL;DR: In this paper, a method for preparing a pyrethroid insecticide of general formula, where the two hydrogen atoms on the cyclopropane ring are in the cis- configuration, was presented.
Abstract: A method for preparing a pyrethroid insecticide of general formula: ##STR1## wherein the two hydrogen atoms on the cyclopropane ring are in the cis- configuration, in which an acid of formula: ##STR2## is neutralized with a water-soluble base and then reacted in the presence of a phase-transfer catalyst with a solution in a substantially water-immiscible organic solvent of an alpha-cyanobenzyl aryl sulphonate of formula: ##STR3## the substituents in the formulae having the following meanings; A represents an optionally substituted aryl group; R 1 and R 2 represent hydrogen or halogen; and R 3 and R 4 represent chlorine, bromine, or methyl.

Journal ArticleDOI
TL;DR: In this paper, cyclopropane adsorbs molecularly into two different adsorption sites up to a saturation coverage of 6.6×1014 cm−2.
Abstract: Thermal desorption mass spectrometry (TDMS), UV photoelectron spectroscopy (UPS), low‐energy electron diffraction (LEED), and contact potential difference measurements have been employed to study the interaction of cyclopropane with the reconstructed Ir (110)–(1×2) surface. At an adsorption temperature of 100 K cyclopropane dissociates on the surface with a reaction probability of 0.87±0.1. This overlayer saturates at a coverage of cyclopropane of (2.1±0.2)×1014 cm−2. Upon further exposure, cyclopropane adsorbs molecularly into two different adsorption sites up to a saturation coverage of 6.6×1014 cm−2. The parameters of the desorption rate coefficients based upon Arrhenius constructions for low coverages of the two desorption states are Ed = 6.4±1 kcal mol−1 and νd = 1.0×109±1 s−1, Ed = 8.3±1 kcal mol−1 and νd = 4.5×1010±2 s−1. The work function decreases by 0.5 eV during formation of the dissociated hydrocarbon residue at 100 K and decreases further (a total decrease of 0.7 eV) during the adsorption of ...

Journal ArticleDOI
TL;DR: In this paper, Hartree and Fock calculated the structure and vibrational frequencies of cyclopropane and cyclophane radical and found that the αCH bond in the radical is bent 39.3° out of the CCC plane, the inversion barrier is 3.0 kcal/mol and the pyramidal bending mode has a frequency of 713 cm−1.
Abstract: Ab initio Hartree–Fock calculations of the structure and vibrational frequencies of cyclopropane and cyclopropyl radical are presented. It is found that the αCH bond in the radical is bent 39.3° out of the CCC plane, the inversion barrier is 3.0 kcal/mol and the pyramidal bending mode has a frequency of 713 cm−1. Compared to cyclopropane, the αCC bonds are stronger, and the βCC bond is weaker in the radical. The shortening of the αCH bond, and the hyperconjugative interaction of the unpaired electron onto the βCH bonds previously observed in alkyl radicals, are found to be much less pronounced in the cycloproply radical.


Journal ArticleDOI
TL;DR: In this article, the enthalpies of cyclopropane, 1,1-dimethylcyclopropane and cyclopropylamine are measured by vaporization calorimetry, and combined with liquid state heats of formation to give gaseous state heat of formation.
Abstract: Heats of vaporization of cyclopropyl cyanide and cyclopropylbenzene have been measured by vaporization calorimetry, and combined with liquid state heats of formation to give gaseous state heats of formation. When these compounds, cyclopropane, 1,1-dimethylcyclopropane, and cyclopropylamine are involved in (hypothetical) isodesmic reactions with ethane to give the isopropyl derivative and propane, the enthalpies of reaction are −116.0 ± 1.3 kJ mol−1, except for cyclopropylbenzene (−103.7 kJ mol−1). The latter is less exothermic, in part, because of slight steric destabilization of the product, isopropylbenzene, but mainly due to 8 kJ mol−1 stabilization of cyclopropylbenzene, which is the only of these cyclopropyl derivatives showing appreciable thermochemical stabilization.

Journal ArticleDOI
TL;DR: In this paper, the (2 S, 3 R ) isomer of 2-methoxymethyl-2,3-dideuterio-1-(Dideuteriomethylene)cyclopropane has been synthesized and heated at 198.8°.

Journal ArticleDOI
TL;DR: The interaction of cyclopropane with hydrogen and the residue resulting from the decomposition of the former on the reconstructed Ir(110)-(1×2) surface has been studied with thermal desorption mass spectrometry as discussed by the authors.

Journal ArticleDOI
TL;DR: For the coordinated double bonds 1J(CC) lies between the value for free ethylene and cyclopropane, and therefore gives direct insight into the relevant bonding situation.

Patent
05 May 1982
TL;DR: In this paper, a set of new and novel alkyl esters were made from new and made by novel processes, which are made from the corresponding alkyls esters which exhibit insecticidal and acaricidal activity.
Abstract: 2-Phenyl-alk-1-enyl-cyclopropane-carboxylic acid esters of the formula ##STR1## in which R each independently is hydrogen, halogen, cyano, nitro and, in each case optionally halogen-substituted, alkyl, alkoxy, alkylenedioxy or alkylthio, R 1 is optionally halogen-substituted alkyk, and R 2 is a radical customary in the alcohol part of pyrethroids which exhibit insecticidal and acaricidal activity. They are made from the corresponding alkyl esters which are new and made by novel processes.


Journal ArticleDOI
TL;DR: The reaction of the 4-mercaptoazetidin-2-one with benzyl 2-bromocyclopropylideneacetate (B2B) gave the C-3 epimeric cyclopropanespiro-2bisnorpenicillanates (9) and (10).
Abstract: Reaction of the 4-mercaptoazetidin-2-one (6) with benzyl 2-bromocyclopropylideneacetate (7) gave the C-3 epimeric cyclopropanespiro-2-bisnorpenicillanates (9) and (10). Standard procedures were used to convert the 3S-epimer into the ampicillin analogue (15). Hydrogenolysis of the esters (9) and (15) gave the cyclopropane spiro-2-bisnorpenicillanic acids (13) and (16) both of which had antibacterial properties similar to those of the corresponding penicillins.

Journal ArticleDOI
TL;DR: The title compound was prepared to complete a series of small ring (cyclopropane, cyclobutane) cis/trans 1,2-disubstituted semirigid congeners of acetylcholine, which were equipotent as muscarinic agonists, but they were much weaker than acetyl-beta-methylcholine.
Abstract: The title compound was prepared to complete a series of small ring (cyclopropane, cyclobutane) cis/trans 1,2-disubstituted semirigid congeners of acetylcholine. A multistep synthetic sequence, beginning with cis-cyclobutane-1,2-dicarboxylic anhydride, permitted unequivocal preparation of the (+/-)-cis target compound 4. The geometry of 4 was confirmed by comparison with an authentic sample of the (+/-)-trans isomer. The cis and trans isomers were equipotent as muscarinic agonists, but they were much weaker than acetyl-beta-methylcholine.

Journal ArticleDOI
TL;DR: The cycloaddition of the bicyclic monoterpenes camphene (4), α-pinene (5), β-pinenes (6), 2-carene (7), bornene (8), and tricyclane 9 with PTAD was investigated as mentioned in this paper.
Abstract: The cycloaddition of the bicyclic monoterpenes camphene (4), α-pinene (5), β-pinene (6), 2-carene (7), bornene (8), and tricyclane 9 with PTAD was investigated. Only camphene and α-pinene gave rearranged urazoles (11, 14) via dipolar cycloaddition. Ene-reaction was the predominant reaction course for α-pinene (→15) and the exclusive route for β-pinene (→16) and 2-carene (→17). Steric hindrance by the gem-dimethyl group prevents cycloaddition of bornene. The cyclopropane rings in the tricyclane 9 and 2-carene are not sufficiently strained to undergo [2π + 2σ]-cycloaddition with PTAD. None of the monoterpenes gave [2π + 2σ]-cycloaddition.

Journal ArticleDOI
TL;DR: The stereochemistry of reduction of mixtures of r-1-bromo-1deuterio-c- and t-2-phenylcyclopropane and the cyclized products from 1,1-dibromo 2-(3-butenyl cyclopropane) upon reduction with lithium aluminum hydride give evidence of a configurationally equilibrated cyclopric radical as a reaction intermediate as mentioned in this paper.

Journal ArticleDOI
TL;DR: Secondary deuterium kinetic isotope effects indicate that the CN bond anti to the Me group on 4-ethylidene-1-pyrazoline breaks preferentially to the syn bond as discussed by the authors.