Disubstituted Derivative Research Articles

1,1′-Bis{α-[(4-methylbenzyl)imino]benzyl}ferrocene

The title compound, [Fe(C20H18N)2], a new 1,1′-disubstituted ferrocenylketimine derivative, has been synthesized and characterized. All the bond lengths are within normal range.

Synthesis and X‐Ray Analysis of a New [6]Helicene

A new disubstituted hexahelicene derivative 3 bearing methoxy functions at positions 3 and 14 has been prepared in racemic form through a Heck reaction followed by photocyclodehydrogenation. Suitable crystals of rac‐3 were analyzed by X‐ray crystallography and showed similar geometry to the structure of hexahelicene itself. Deprotection of 3 using boron tribromide led to 3,14‐dihydroxyhexahelicene 4 in quantitative yield. The complexation of transition metal atoms seemed to be quite possible by these two bidentate hexahelicene derivatives.

Nitrile Glove Permeation of Benomyl

The aim of this study was to investigate permeation of the fungicide benomyl at its highest field application concentration (0.70 mg/mL) in Benlate 50 WP aqueous solution (1.4 mg/mL) through two types of unsupported and unlined nitrile gloves--a disposable latex glove (Safeskin) and an industrial chemical-resistant glove (Solvex)--using an American Society for Testing and Materials (ATSM)-type permeation cell with isopropanol collection medium. The permeation cell was contained in a moving-tray water bath at 30.0 degrees C +/- 0.5 degrees C. The collection medium was evaporated and the residue derivatized with an optimized method (2,3,4,5,6-pentafluoro)benzyl bromide to form the disubstituted derivative of carbendazim (CARB), CARB.2PFB. The latter in isooctane was then quantified by gas chromatography- 63Ni-electron capture detection (GC-ECD) by the internal standard method. GC-ECD, GC-mass spectrometry (GC-MS), and reflectance infrared investigations showed that little degradation of benomyl occurred in the challenge solution of aqueous Benlate during an 8-hour exposure period. Benomyl was collected as a mixture of CARB and benomyl as shown by the presence of a diagnostic chromatographic peak identified by GC-MS. The amounts permeated during the same time period were always higher for Safeskin than for Solvex gloves, with the latter being approximately 18 times more protective than the former after 8 hours of continuous exposure. Although the Solvex gloves were safe to wear at least for 4 hours and for almost 8 hours, the ASTM breakthrough threshold was used as reference and thus ignored carcinogenic effects. Reflectance infrared investigations detected benomyl and CARB on the glove challenge surface after drying and confirmed that the cleaned glove surfaces after permeation experiments did not differ in infrared reflectance spectra from the corresponding surfaces just before the permeation experiments.

Syntheses and Physical Properties of Ferrocene Derivatives (XVII) Crystal Structure of a Liquid Crystalline Ferrocene Derivative, 1,1′-bis[5-[4-(4-methoxyphenoxycarbonyl)phenoxy] pentyloxycarbonyl]ferrocene

ABSTRACT The molecular and crystal structures of 1,1′-disubstituted ferrocene derivative, 1,1′-bis[5-[4-(4-methoxyphenoxycarbonyl)phenoxy]pentyloxycarbonyl]ferrocene (bMAF-5) were determined by X-ray diffraction method using a single crystal. This compound is a liquid crystalline one. As generally expected, the molecular feature is “S” shape in which the two substituents are present in the opposite directions. The ‒C5H10 − chain introduced into the molecule as a flexible spacer includes two gauche conformations. The gauche conformation plays an important role to make a rod-like shape, which is favorable to show liquid crystallinity.

A Novel Molecular Structure of a Ferrocene Derivative Containing Mesogenic Group, 1,1′-Bis[2-[4-(4-methoxyphenoxycarbonyl)phenoxy]ethoxycarbonyl]ferrocene

Abstract The molecular and crystal structures of 1,1′-disubstituted ferrocene derivative, 1,1′-bis[2-[4-(4-methoxyphenoxycarbonyl)phenoxy]ethoxycarbonyl]ferrocene (bMAF-2) were determined by X-ray diffraction method using the single crystals. The trans conformation (novel “Z” shape) in which the two substituents existed in the opposite directions was found out newly. The structure was different from the cis conformation (“U” shape) and the trans conformation (“S” shape) reported already. It may be one of the most important reasons why bMAF-2 (“Z” shape) shows no liquid crystallinity that the ratio of the width to length is rather large compared with those of other liquid crystalline homologues (“U” shape and “S” shape).

Aminoparathion: A Highly Reactive Metabolite of Parathion. 1. Reactions with Polyphenols and Polyphenol Oxidase

Spiking of tomato and apple fruits with parathion at different levels of about 1-4 mg/kg irradiation and under simulated sunlight conditions resulted in nearly complete photodegradation within 13 h, but extractable parathion degradation products could not be found in any case. However, after irradiation of an unrealistically spiked apple (134 mg/kg) different photoproducts including aminoparathion (AP) were detectable by HPLC, proving that the hitherto postulated photochemistry of parathion indeed takes place in the fruit cuticle environment. Besides the photoreduction pathway it was shown for the first time that AP is also easily formed by reduction of the primary photoproduct nitrosoparathion with thiols (cysteine, glutathione), while ascorbic acid only leaves hydroxylaminoparathion. In the presence of polyphenols, AP was effectively bound to quinone intermediates formed by both silver oxide and polyphenol oxidases. For pyrocatechol, a disubstituted o-quinone derivative could be isolated as a dark red addition product and structurally be elucidated. However, in the presence of caffeic acid, catechol, naringin, and quercetin, respectively, insoluble dark colored polymers precipitated within 48 h, while in the supernatants AP was not detectable any more. Polymer-bound and nonextractable AP was proven by transesterification with sodium ethoxide releasing O,O,O-triethyl thiophosphate which was determined by GC. Additionally, AP itself was a substrate for polyphenol oxidases, resulting in a quinone imine intermediate which in turn reacted with excessive AP yielding deep red colored di- and trimerization products.

Evidence for a racemisation reaction giving diastereoisomers in the aminolysis of a chiral tetra-aminocyclotriphosphazene

The reactions of racemic trans-1,3-bis(dibenzylamino)-1,3,5,5-tetrachlorocyclotriphosphazene ( 2) with an excess of pyrrolidine under progressively more forcing conditions gave successively derivatives with bis, tris and tetrakis-pyrrolidino substitution; viz. 5,5-bispyrrolidino- trans-1,3-bis(dibenzylamino)-1,3-dichlorocyclotriphosphazene ( 3), 1,5,5-trispyrrolidino- cis and 1,5,5-trispyrrolidino- trans-1,3-bis(dibenzylamino)-3-chlorocyclotriphosphazene ( 4) and 1,3,5,5-tetrakispyrrolidino- cis-1,3 and 1,3,5,5-tetrakispyrrolidino- trans-1,3-bis(dibenzylamino)cyclotriphosphazene ( 5). It was shown by 31P NMR spectroscopy that on addition of a chiral solvating agent the gem di-substituted derivative ( 3) is a racemate, that the tris-pyrrolidino derivative ( 4) exists as a pair of racemic diastereoisomers, and that the tetrakis-pyrrolidino derivative ( 5) is also diastereoisomeric, but exists as a racemic and meso pair of molecules. Compound ( 4) can only be formed as a result of a racemisation reaction, which may indicate an S N1 reaction in going from the tetrakis-amino substituted derivative ( 3) to the pentakis-amino derivative ( 4), and probably also to the hexakis-amino derivative ( 5).

Effect of Initiator on the Microstructure of Copolymers of Acrylic Acid with a Disubstituted Derivative of Monoethanolamine Vinyl Ether and Chloranil

The influence of the initiator on the copolymerization of acrylic acid with a disubstituted derivative of monoethanolamine vinyl ether and chloranil was examined.

Novel structure of 1,1'-disubstituted ferrocene derivative

Novel structure of 1,1'-disubstituted ferrocene derivative

A structural, magnetic and Mössbauer spectroscopic study of an unusual angular Jahn–Teller distortion in a series of high-spin iron(ii) complexes

Single crystal X-ray structures and susceptibility data are described for six homoleptic iron(II) complex salts, of 2,6-di(pyrazol-1-yl)pyridine or a 3,3"-disubstituted derivative of it. Zero field Mossbauer spectroscopic data for four of the complexes, and one previously reported analogue, are also discussed. Four of these compounds exhibit an unusual angular Jahn-Teller distortion towards C(2) symmetry to differing degrees, while the other two exhibit structures close to the "ideal" D(2d) symmetry for this ligand set. This structural distortion has two components: a twisting of the plane of one ligand relative to the other about the N{pyridine}-Fe-N{pyridine} vector, so that the two ligands are no longer perpendicular; and a rotation of one ligand about the Fe ion, so that the N{pyridine}-Fe-N{pyridine} angle < 180 degrees. Susceptibility data show that all the complexes are fully high-spin between 5 and 300 K, but yield an unusually wide range of zero-field splitting parameters for the different compounds of between 2.6 and 13.4 cm(-1). Magnetostructural correlations suggest that a low value of |D| is diagnostic for a high degree of "rotation" distortion. The Mossbauer spectra imply that an increased quadrupole splitting might also be diagnostic for the presence of the angular distortion.

Crystal Structure of a Liquid Crystalline Ferrocene Derivative, 1,1′-bis[10-[4-(4-methoxyphenoxycarbonyl)phenoxy]decyloxycarbonyl]ferrocene

Abstract The molecular and crystal structures of 1,1′-disubstituted ferrocene derivative, 1,1′-bis[10-[4-(4-methoxyphenoxycarbonyl)phenoxy]decyloxycarbonyl]ferrocene (bMAF-10) were determined by X-ray diffraction method using the single crystals. The structural molecular feature was the cis conformation (“U” shape) in which the two substituents existed in the same directions, but not the trans conformation (“S” shape) expected in general.

Synthesis and structural studies of a novel scaffold for drug discovery: a 4,5-dihydro-3 H-spiro[1,5-benzoxazepine-2,4 ′-piperidine

We describe the three-step synthesis of a novel 4,5-dihydro-3 H-spiro[1,5-benzoxazepine-2,4 ′-piperidine] scaffold from ortho-hydroxyacetophenone and N-benzylpiperidone. The structure of one disubstituted derivative, studied by NOESY NMR in an aqueous medium and X-ray diffraction, demonstrates that this scaffold presents side chains in a well-defined orientation. The Boc protected derivative represents a key intermediate for the combinatorial synthesis of drug-like molecules.

2,3-bis(2-methylphenylimino)-1,4-dithiacyclohexane.

An N,N'-disubstituted dithiooxamide derivative reacts with 1,2-dibromoethane to produce the title compound, C(18)H(18)N(2)S(2), a heterocycle with a double Schiff base. In the crystal structure, the molecule of the title compound lies on a twofold axis. Weak C-H...pi interactions are the principal intermolecular forces, mediating the formation of layers parallel to the ab plane. Each molecule participates as donor and acceptor in two such contacts.

Experimental and Computational Study of the Kinetics of OH + Pyridine and Its Methyl- and Ethyl-Substituted Derivatives

The overall rate constants for the reaction of OH with pyridine, its three monosubstituted methyl derivative isomers (the picolines), its six disubstituted methyl derivative isomers (the lutidines), and its three monosubstituted ethyl derivative isomers have been measured using the turbulent flow technique with high-pressure chemical ionization mass spectrometry at 100 Torr pressure and 298 K. A structure−reactivity relationship model for parametrizing the OH rate constants based on the type and position of the methyl and ethyl substituents on the pyridine ring has been constructed, and similar accuracy to that previously obtained for benzene derivative rate data is achieved. Transition state theory calculations have been performed to explore the substituent effect on the observed OH rate constants. The atmospheric implications of the findings are discussed in terms of the role of pyridinated compounds in the ionic composition of the troposphere.

High molecular weight hydrophilic functional copolymers by free‐radical copolymerization of acrylamide and ofN‐acryloylmorpholine withN‐acryloxysuccinimide: Application to the synthesis of a graft copolymer

AbstractFree‐radical solution copolymerization of acrylamide (AAm) and of a disubstituted acrylamide derivative,N‐acryloylmorpholine (NAM), with N‐acryloxysuccinimide (NAS) was investigated with the aim to obtain a copolymer of at least 100,000 g mol−1. Different polymerization conditions likely to increase the molecular weight were studied such as monomer and initiator concentrations, temperature, and nature of the solvent. The molecular weights were determined by SEC using a light‐scattering detector. The grafting of end‐functionalized polysaccharide chains onto such high molecular weight poly(NAM‐co‐NAS) was performed and a graft copolymer bearing a high number of saccharidic branches was obtained. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1808–1816, 2003

2-(Pyrrolidin-1-yl)-1,4-naphthoquinone and 2-phenylsulfanyl-3-(pyrrolidin-1-yl)-1,4-naphthoquinone.

The structure of 2-(pyrrolidin-1-yl)-1,4-naphthoquinone, C(14)H(12.95)Cl(0.05)NO(2), (I), is actually a 0.95:0.05 mixture including 2-chloro-3-(pyrrolidin-1-yl)-1,4-naphthoquinone as a minor impurity, but (I) was resolved as a single molecule containing a Cl atom with 5% occupancy at the 3-position. Compound (I) was prepared from the fully chloro-substituted analogue in an attempt to produce the disubstituted pyrrolidinyl derivative. 2-Phenylsulfanyl-3-(pyrrolidin-1-yl)-1,4-naphthoquinone, C(20)H(17)NO(2)S, (II), was also prepared from 2-chloro-3-(pyrrolidin-1-yl)-1,4-naphthoquinone, using a strong exocyclic nucleophile. The structure of (II) differs from previous structures of 2,3-dichloro-1,4-naphthoquinone and its derivatives in that the naphthoquinone ring is non-planar.

Regioselective Addition of Dienes to the Cβ−Cγ Double Bond of the Allenylidene Ligand of [Ru(η5-C5H5)(CCCPh2)(CO)(PiPr3)]BF4

The Cβ−Cγ bond of the allenylidene ligand of [Ru(η5-C5H5)(CCCPh2)(CO)(PiPr3)]BF4 (1) adds dienes such as isoprene, cyclopentadiene, and 1,3-cyclohexadiene. The reaction with isoprene selectively affords the disubstituted vinylidene derivative (2), whereas in the presence of cyclopentadiene a 1:1 mixture of the diastereomers (3) and (4) is obtained. In contrast to the addition of cyclopentadiene, the reaction with 1,3-cyclohexadiene is diastereoselective and gives only the racemic mixture of one diastereomer: (5). The structures of 2, 3, and 5 have been determined by X-ray diffraction analysis. In the three cases, the geometry around the ruthenium center is close to octahedral, with the cyclopentadienyl ligand occupying one face.

Preparation of Complexes Formed in the Reaction Between Dicobaltoctacarbonyl and Tetraalkyldiphosphine Disulfides, R2P(S)P(S)R2 (R = Me, Et, N-Pr, N-Bu)

Co2(CO)8 and R2P(S)P(S)R2 (R = Me, Et, n-Pr, n-Bu) react to form the three types of cluster complexes [Co2(μ-CO)(μ4-S)(CO)4]2, (1), [Co4(CO)9(μ3-S)(μ-PR2)2] (2A)-(2D), [(2A), R = Me; (2B), R = Et; (2C), R = n-Pr; (2D), R = n-Bu] and [Co3(CO)7(μ3-S)(SPR2)] (3A)-(3D), [(3A), R = Me; (3B), R = Et; (3C), R = n-Pr, (3D), R = n-Bu]. The structure of (2A) and the disubstituted triphenylphosphine derivative of (3A) were reported previously. The complexes have been characterized by elemental analyses, FT-IR and 311P-[1H] NMR spectroscopy and mass spectrometry

Stereospecific synthesis of α -methylated amino acids

Both 2,5-trans and 2,5-cis disubstituted 2-tert-butyl-5-(indol-3-yl)methylimidazolidin-4-ones were synthesised and their enolates were prepared using LDA. While the enolate of the 2,5-trans disubstituted derivative could not be methylated, the enolate of the cis-2,5-disubstituted derivative was successfully methylated with methyl iodide to a product which on hydrolysis gave enantiomerically pure alpha-methyl-L-tryptophan.

Selective Synthesis of Indenylruthenium(II) Vinylvinylidene Complexes via Unstable Allenylidene Intermediates: Unexpected Formation of Alkenyl−Phosphonio Complexes (E)-[Ru{C(H)C(PPh3)R}(η5-C9H7)(PPh3)2][PF6] (R = 1-Cyclohexenyl, 1-Cycloheptenyl) through Nucleophilic Addition of Triphenylphosphine on Vinylvinylidene Derivatives

The vinylvinylidene = PPh3, L2 = 1,2-bis(diphenylphosphino)ethane (dppe); n = 1 (2a,b), 2 (3a,b), 3 (4a,b)) have been prepared by reaction of [RuCl(η5-C9H7)L2] with 1-ethynyl-1-cycloalkanols and NaPF6 in refluxing methanol. Deprotonation of the vinylidene derivatives with Al2O3 yields the neutral enynyl 6a,b, and 7a,b). The reaction of the enynyl complex [Ru(C⋮CR)(η5-C9H7)(PPh3)2] (R = 1-cyclohexenyl; 6a) with MeOSO2CF3 produces the disubstituted vinylvinylidene derivative [Ru{CC(Me)R}(η5-C9H7)(PPh3)2][CF3SO3] (R = 1-cyclohexenyl; 8a). The crystal structure of 8a was determined by X-ray diffraction methods. In the structure the RuCC chain is nearly linear (Ru−C(1)−C(2) = 176.2(4)°) with an Ru−C(1) distance of 1.838(5) Å. The indenyl ligand is η5-bonded to the metal with the benzo ring orientated “trans” with respect to the vinylidene group. When the reaction of [RuCl(η5-C9H7)(PPh3)2] with 1-ethynylcyclohexanol or 1-ethynylcyclopentanol and NaPF6 takes place in the presence of PPh3, the alkynyl−phosphonio = 1 (11a), 2 (12a)) were obtained via nucleophilic attack of the PPh3 on Cγ of the unstable allenylidene = 1 (9a), 2 (10a)). The vinylvinylidene complexes 3a (n = 2) and 4a (n = 3) also react with PPh3, giving the alkenyl−phosphonio = 2 (13a), 3 (14a)). The structure of 13a was confirmed by X-ray diffraction methods. A possible mechanism for the formation of 13a and 14a is proposed.