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PubMed2005

First synthesis of enantiopure 1,6-difunctionalized dodecahydrobenz[f]indenes.

An enantiospecific route to the previously unreported 1,6-difunctionalized dodecahydrobenz[f]indene ring system is described. Optically pure Hajos-Parrish ketone is used as the building block for preparation of a 6-methyleneinden-5-ol. This allylic alcohol is then utilized in a Claisen rearrangement under Johnson's conditions to introduce a side chain that is further modified and cyclized to produce the benz[f]indene ring system.

GABA Agents↗
PubMed2006

Formation of naphthalene, indene, and benzene from cyclopentadiene pyrolysis: a DFT study.

Four new reaction pathways for polycyclic aromatic hydrocarbon growth from cyclopentadiene pyrolysis are proposed and investigated using the B3LYP/6-31G(d,p) level of theory. These pathways allow for the production of indene, naphthalene, and benzene through intramolecular addition, C-H beta-scission, and C-C beta-scission reaction mechanisms, respectively. Results show that the intramolecular addition channel is favored at low temperatures, and the C-H beta-scission channel and the newly identified C-C beta-scission pathway become significant when the temperature increases. These results are in qualitative agreement with the experimental results previously obtained by this research group indicating that the main product at low temperature is indene, while benzene and naphthalene production dominate at the high-temperature end.

Algorithms↗
PubMed2006

Cyanosporasides A and B, chloro- and cyano-cyclopenta[a]indene glycosides from the marine actinomycete "Salinispora pacifica".

[structure: see text] Two structurally novel cyclopenta[a]indene glycosides, cyanosporasides A and B (1 and 2) have been isolated from the culture broth of a new species of the obligate marine actinomycete genus Salinispora. The structures and absolute stereochemistries of these compounds were determined by spectral and chemical methods. The cyanosporasides possess a new 3-keto-pyranohexose sugar as well as a cyano- and chloro-substituted cyclopenta[a]indene ring system. The cyanosporasides are proposed to be cyclization products of an enediyne precursor.

Actinobacteria↗
PubMed2005

Recent developments in the medicinal chemistry of cannabimimetic indoles, pyrroles and indenes.

During the development of new nonsteroidal anti-inflammatory agents, it was discovered that 1-aminoalkyl-3-aroylindoles have affinity for the cannabinoid brain (CB(1)) receptor. This has led to the development of over 100 cannabimimetic aminoalkylindoles, and the development of SAR for these compounds. Later work demonstrated that the aminoalkyl moiety was not necessary, and could be replaced by a four- to six-membered alkyl chain without loss of affinity. Investigation of these indoles led to the discovery of a CB(2) selective ligand, 3-(1-naphthoyl)-N-propylindole. Subsequent work has provided several additional CB(2) selective indoles. On the basis of a proposed pharmacophore for the cannabimimetic indoles, a series of pyrroles and indenes were developed, some of which are potent cannabinoids. SAR for several series of pyrroles have been developed. Two groups have described cannabimimetic indenes, which have been employed as rigid models for the receptor interactions of cannabimimetic indoles with the CB(1) receptor. There is some evidence that the indoles bind to a somewhat different site on the receptor than traditional cannabinoids, and interact with the receptor primarily by aromatic stacking.

Animals↗
PubMed2001

Structural assignment of isomeric 2-(2-quinolinyl)-1H-indene-1,3(2H)-dione mono- and disulfonic acids by liquid chromatography electrospray and atmospheric pressure chemical ionization tandem mass spectrometry.

Positionally isomeric 2-(2-quinolinyl)-1H-indene-1,3(2H)-dione mono- and disulfonic acids give rise to similar electrospray ionization (ESI) and atmosphere pressure chemical ionization (APCI) mass spectra, which show very abundant MH(+) ions and negligible fragmentation. The MH(+) ions of these isomeric acids exhibit notably different behavior under collision-induced dissociation (CID) conditions. The acids with a sulfonic group at position 8' in the quinoline moiety, adjacent to the N-atom, exhibit highly abundant [MH - H(2)SO(3)](+) ions (m/z 272 for the mono- and m/z 352 for the disulfonic acids), which are of lower abundance in the CID spectra of isomers with the SO(3)H group at other positions, remote from the nitrogen atom. The latter isomers undergo efficient eliminations of SO(3) and HSO(3). The isomeric diacids with one SO(3)H group at position 4 of the indene-1,3(2H)-dione moiety, adjacent to one of the carbonyl groups, undergo highly efficient elimination of H(2)O. Mechanistic pathways, involving interactions between adjacent groups, are proposed for the above regiospecific fragmentations. Pronounced different behavior has been also observed in negative ion tandem mass spectrometric measurements of the sulfonic acids. The distinctive behavior of the isomeric acids was strongly pronounced when the measurements were performed with an ion trap mass spectrometer (LCQ), and much less so with a triple-stage quadrupole instrument (TSQ).

Coloring Agents↗
PubMed2001

Preparative separation of isomeric 2-(2-quinolinyl)-1H-indene-1,3(2H)-dione monosulfonic acids of the color additive D&C Yellow No. 10 (quinoline yellow) by pH-zone-refining counter-current chromatography.

The main components of the color additive D&C Yellow No. 10 (Quinoline Yellow, Color Index No. 47005), 2-(2-quinolinyl)-1H-indene-1,3(2H)-dione-6'-sulfonic acid (6SA) and 2-(2-quinolinyl)-1H-indene-1,3(2H)-dione-8'-sulfonic acid (8SA), were isolated from the dye mixture by pH-zone-refining counter-current chromatography (CCC) in the ion-exchange mode. These positional isomers were separated from a portion of dye using sulfuric acid as the retainer acid and dodecylamine as the ligand (ion exchanger). The added ligand enhanced the partitioning of the hydrophilic components in the organic stationary phase of the two-phase solvent system that consisted of isoamyl alcohol-methyl tert.-butyl ether-acetonitrile-water (3:1:1:5). Thus, separation of 1.8 g of D&C Yellow No. 10 using the above method resulted in 0.6 g of 6SA and 0.18 g of 8SA of over 99% purity. The isolated compounds were characterized by mass spectrometry and proton nuclear magnetic resonance with correlated spectroscopy assignments. The study exemplifies a new field of applications for pH-zone-refining CCC, to the separation of positional isomers of strongly hydrophylic compounds containing sulfonic acid groups.

Chromatography, High Pressure Liquid↗
PubMedDate not supplied

Aromatic hydrocarbon growth from indene.

Aromatic hydrocarbon growth from indene (C9H8), which contains the five-membered ring cyclopentadienyl moiety, was investigated experimentally in a 4 s flow reactor over a temperature range 650-850 degrees C. Major products observed were three C18H12 isomers (chrysene, benz[a]anthracene and benzo[c]phenanthrene), two C17H12 isomers (benzo[a]fluorene and benzo[b]fluorene), and two C10H8 isomers (naphthalene and benzofulvene). Reaction pathways to these products are proposed. Indenyl radical addition to indene produces a resonance-stabilized radical intermediate which further reacts by one of two routes. Rearrangement by intramolecular addition produces a bridged structure that leads to the formation of C17H12 and C10H8 products. Alternatively, beta scission produces biindenyl, which leads to the formation of C18H12 products by a ring condensation mechanism analogous to that proposed for cyclopentadiene-to-naphthalene conversion. Temperature dependencies of both the partitioning between these two routes and the product isomer distributions are consistent with thermochemical modeling using semi-empirical molecular orbital methods. The results further illustrate the role of resonance-stabilized radical rearrangement in aromatic growth and condensation of systems with cyclopentadienyl moieties.

Journal Article↗
PubMed2001

Biradicals from benzoenyne-allenes. Application in the synthesis of 11H-benzo[b]fluoren-11-ols, 1H-cyclobut[a]indenes, and related compounds.

New synthetic pathways to 11H-benzo[b]fluoren-11-ols, 1H-cyclobut[a]indenes, and related compounds via biradicals generated from benzoenyne-allenes were developed. Treatment of the diacetylenic propargylic alcohols 13, derived from condensation between benzophenones and the lithium acetylide of 1-(2-ethynylphenyl)-2-phenylethyne, with thionyl chloride produced the 11-chloro-11H-benzo[b]fluorene 14 and, after hydrolysis, the corresponding 11H-benzo[b]fluoren-11-ols 15. The transformation involved a sequence of reactions, including a biradical-forming C2-C6 cyclization (Schmittel cyclization) reaction of the chlorinated benzoenyne-allene intermediates followed by an intramolecular radical-radical coupling to form the formal Diels-Alder adducts. Interestingly, in the case of the diacetylenic propargylic alcohol 26, obtained from dibenzosuberenone (25), an intramolecular [2 + 2] cycloaddition reaction of the chlorinated benzoenyne-allene intermediate occurred, furnishing the 1H-cyclobut[a]indene 27 exclusively. The dramatic change of the reaction pathway could be attributed to the emergence of a steric strain due to the nonbonded interactions with the chloro substituent along the pathway toward the formal Diels-Alder adduct 31. On the other hand, the non-chlorinated benzoenyne-allene, derived from prototropic isomerization of the diacetylenic hydrocarbon 60, underwent a formal Diels-Alder reaction to furnish the 11H-benzo[b]fluorene-type hydrocarbon 61 exclusively.

Journal Article↗
PubMed2006

Novel dimetal bridging carbene complexes derived from a terminal carbonyl dimetal compound. Syntheses, structures and reactivities of 7H-indene-coordinated diiron bridging carbene complexes.

Pentacarbonyl-7H-indenediiron, [Fe2(CO)5(eta3,eta5-C9H8)] (1), reacts with aryllithium, ArLi (Ar = C6H5, p-C6H5C6H4), followed by alkylation with Et3OBF4 to give novel 7H-indene-coordinated diiron bridging alkoxycarbene complexes [Fe2{mu-C(OC2H5)Ar}(CO)4(eta4,eta4-C9H8)] (2, Ar = C6H5; 3, Ar = p-C6H5C6H4). Complexes 2 and 3 react with HBF4.Et2O at low temperature to yield cationic bridging carbyne complexes [Fe2(mu-CAr)(CO)4(eta4,eta4-C9H8)]BF4 (4, Ar = C6H5; 5, Ar = p-C6H5C6H4). Cationic 4 and 5 react with NaBH4 in THF at low temperature to afford diiron bridging arylcarbene complexes [Fe2{mu-C(H)Ar}(CO)4(eta4,eta4-C9H8)] (6, Ar = C6H5; 7, Ar = p-C6H5C6H4). The similar reactions of 4 and 5 with NaSC6H4CH3-p produce the bridging arylthiocarbene complexes [Fe2{mu-C(Ar)SC6H4CH3-p}(CO)4(eta4,eta4-C9H8)] (8, Ar = C6H5; 9, Ar = p-C6H5C6H4). Cationic 4 and 5 can also react with anionic carbonylmetal compounds Na[M(CO)5(CN)] (M = Cr, Mo, W) to give the diiron bridging aryl(pentacarbonylcyanometal)carbene complexes [Fe2{mu-C(Ar)NCM(CO)5}(CO)4(eta4,eta4-C9H8)] (10, Ar = C6H5, M = Cr; 11, Ar = p-C6H5C6H4, M = Cr; 12, Ar = C6H5, M = Mo; 13, Ar = p-C6H5C6H4, M = Mo; 14, Ar = C6H5, M = W; 15, Ar = p-C6H5C6H4, M = W). Interestingly, in CH2Cl2 solution at room temperature complexes 10-15 were transformed into the isomerized 7H-indene-coordinated monoiron complexes [Fe(CO)2(eta5-C9H8)C(Ar)NCM(CO)5] (16, Ar = C6H5, M = Cr; 17, Ar = p-C6H5C6H4, M = Cr; 18, Ar = C6H5, M = Mo; 19, Ar = p-C6H5C6H4, M = Mo; 20, Ar = C6H5, M = W; 21, Ar = p-C6H5C6H4, M = W), while complex 3 was converted into a novel ring addition product [Fe2{C(OC2H5)C6H4C6H5-p-(eta2,eta5-C9H8)}(CO)5] (22) under the same conditions. The structures of complexes 2, 6, 8, 14, 18 and 22 have been established by X-ray diffraction studies.

Journal Article↗
PubMed2000

Racemic and chiral 1-[N-(chloroacetyl)carbamoylamino]-2, 3-dihydro-1H-inden-2-yl chloroacetate.

In the racemic crystals of (1S,2R)- or (1R, 2S)-1-[N-(chloroacetyl)carbamoylamino]-2,3-dihydro-1H-inden- 2-yl chloroacetate, C(14)H(14)Cl(2)N(2)O(4), (I), the enantiomeric molecules form a dimeric structure via the N-H.O cyclic hydrogen bond of the carbamoyl moieties. In the chiral crystals of (-)-(1S, 2R)-1-[N-(chloroacetyl)carbamoylamino]-2,3-dihydro-1H-inden- 2-yl chloroacetate, C(14)H(14)Cl(2)N(2)O(4), (II), the N-H.O intermolecular hydrogen bond forms a zigzag chain around the twofold screw axis. The melting points and calculated densities of (I) and (II) are 446 and 396 K, and 1.481 and 1.445 Mg m(-3), respectively.

Journal Article↗
PubMedDate not supplied

Liquid chromatographic determination of 2-(2-quinolinyl)-1H-indene-1,3-[2H]-dione and other organic-soluble matter in D&C Yellow No. 10.

A sensitive, reproducible method that uses an Extrelut QE column and liquid chromatography (LC) in the reverse phase mode is described for the determination of 2-(2-quinolinyl)-1H-indene-1,3-[2H]-dione and other organic-soluble matter found in D&C Yellow No. 10. With this method the organic-soluble matter is extracted from D&C Yellow No. 10 on an Extrelut QE column, and the extract is concentrated and analyzed by LC. Recoveries averaged 104% for 2-(2-quinolinyl)-1H-indene-1,3-[2H]-dione added to purified D&C Yellow No. 10 at levels ranging from 0.50 to 5.96 ppm.

Chromatography, Liquid↗
PubMed1981

[Substances with antiviral. XVI. Thiosemicarbazones containing benzofuran and 1H-indene moieties].

A few hydrazones with benzofuran and 1H-indene moieties were synthesized and screened in vitro against vaccinia virus strain IHD, parainfluenza type 3 virus strain HA-1/CR-8, and the MP mutant of herpes simplex virus type 1 [HSV-1 (MP)]. Only the thiosemicarbazones were active. The thiosemicarbazone of 3-chloro-2-formyl-1H-indene inhibited vaccinia virus to a greater extent than methisazone, used as reference standard. Furthermore, this compound was active also against parainfluenza and herpes viruses.

Antiviral Agents↗
PubMedDate not supplied

Bicyclic dioxetanes bearing an inden-2-yl or a benzo(b)thiazol-2-yl moiety as a CIEEL-active chemiluminescent substrate emitting red light.

Bicyclic dioxetanes bearing 5-(t-butyldimethylsiloxy)inden-2-yl, 3, or 5-(t-butyldimethylsiloxy)benzo(b)thiazol-2-yl, 4, were synthesized. On treatment with large excess of tetrabutylammonium fluoride in DMSO, dioxetane, 3, decomposed rapidly with accompanying emission of red (vermilion) light (lambda(max) (CL) = 637 nm). Comparing the chemiluminescent properties for 3 with those for related dioxetane, 1, in which pi-conjugation system is not fixed in plane, both CIEEL-decay rate and chemiluminescent efficiency were found to be improved for 3. Chemiluminescent decomposition of dioxetane, 4, was similarly induced to emit crimson light (lambda(max) (CL) = 725 nm), though the chemiluminescent efficiency was low.

Benzothiazoles↗
PubMed2004

Utilizing hydrolases of opposite enantiopreference for the preparation of both enantiomers of (1R,7aR)-(-)- and (1S,7aS)-(+)-3,6,7,7a-tetrahydro-1-hydroxy-7a-methyl-1H-inden-5(2H)-one.

Four racemic esters of (1R*,7aR*)-3,6,7,7a-tetrahydro-1-hydroxy-7a-methyl-1H-inden-5(2H)-one were prepared and subjected to hydrolysis with two types of hydrolases, including alcalase and three lipases. Alcalase and lipase showed opposite enantiopreference on these esters. Based on this result, we developed a gram-scale procedure using butanoate as the substrate, which was treated consecutively with alcalase and lipase from Candida rugosa (CRL), to give both enantiomers of the title compound in high yields and high enantiomeric excess.

Candida↗
PubMed2002

Multiple-quantum NMR spectra of partially oriented indene: a new approach to estimating order in a nematic phase.

Multiple-quantum proton NMR spectra of the 8-spin system of indene partially oriented in a nematic mesophase were acquired using a magnetic field gradient (MFG) method. Six-, seven- and eight-quantum spectra were solved to yield all intramolecular dipolar couplings (D(ij)) which were used to determine the molecular shape. The spectral widths of multiple-quantum spectra are dependent on molecular orientation and geometry and a novel method was developed to estimate the Saupe order parameters from the observed spectral widths of the high-order multiple-quantum spectra.

Indenes↗
PubMed2004

PAH Growth from the pyrolysis of CPD, indene and naphthalene mixture.

In this study, the addition of cyclopentadienyl (CPDyl) moieties to aromatic rings has been investigated experimenNaphthalene was selected as the representative aromatic compound and its pyrolytic reactivity was studied first to obtain background information for the pyrolysis of cyclopentadiene-indene-naphthalene mixture. The experiments were conducted in a 5 s laminar flow reactor over the temperature range of 700-850 degrees C with 50 degrees C increments. PAH growth from naphthalene pyrolysis is mainly attributed to aryl-aryl addition of naphthyl radicals and naphthalene fragmentation, with lower product formation rates comparing with hydrocarbons with CPDyl moieties. The results indicate that naphthalene is less reactive than the CPDyl containing hydrocarbon radical-molecule addition of CPDyl radicals to naphthalene results in phenanthrene, which can also be formed substantially from other growth pathways. This addition occurs mainly at low temperatures and is less favored due to the competition from more reactive indenyl and CPDyl radicals. CPDyl radical addition to naphthalene exhibits limited aromatic growth due to the aromaticity restrictions of naphthalene. The studies of hydrocarbons with and without CPDyl moieties suggest that the reaction pathways of CPDyl bearing hydrocarbons are different from those without these moieties and cannot be adequately accounted for by the existing acetylene addition and aryl-aryl addition mechanisms.

Cyclopentanes↗