- Fast H/D exchange of B, B′, B′-tribromoborazine in C 6D6 in the presence of aluminum tribromide: First evidence for an electrophilic substitution reaction of borazines in solution
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A solution of B,B′,B′-tribromoborazine (BrBNH)3 in excess C6D6 in a sealed NMR tube shows no changes for over 14 months at room temperature but undergoes fast (within minutes) H/D exchange in the presence of AlBr3 as a Lewis acid, as evidenced by 1H, 2H, 11B, and 27Al NMR spectroscopy. The proposed electrophilic exchange mechanism is in agreement with the results of DFT computations. To our knowledge, this is the first example of the electrophilic substitution reaction of borazines in solution.
- Timoshkin, Alexey Y.,Kazakov, Igor V.,Lisovenko, Anna S.,Bodensteiner, Michael,Scheer, Manfred
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Read Online
- Hybrid 2-aminotetralin and aryl-substituted piperazine compounds and their use in altering cns activity
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Hybrid compounds containing in aminotetralin moiety or a heterocyclic and/or open chain analog thereof linked through an alkylene group to an aryl ring system-substituted piperidiene moiety exhibit high levels of CNS activity, in some cases exhibiting especially high relative binding efficiencies between D3 and D2 dopaminergic receptor subtypes.
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- METHOD FOR COUPLING LIVING CATIONIC POLYMERS
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A method for coupling a living cationic polymer is disclosed, said method comprising reacting the living cationic polymer with an organic compound having at least 2 furan rings in its molecule, said reaction taking place in the presence of a Lewis acid. Preferably, the living cationic polymer is first prepared by polymerizing at least one monomer selected from isobutylene, isoprene or a styrenic monomer using a specific initiator, this reaction also being carried out in the presence of a Lewis acid.
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- Benzothiophenes, benzofurans, and indoles useful in the treatment of insulin resistance and hyperglycemia
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This invention provides compounds of Formula I having the structure E is S, SO, SO2, O, or NR1c; X is hydrogen, halogen, alkyl of 1-6 carbon atoms, alkenyl of 2-7 carbon atoms, CN, aryl, aralkyl of 6-12 carbon atoms, hydroxyalkyl of 1-6 carbon atoms, hydroxyaralkyl of 6-12 carbon atoms, perfluoroalkyl of 1-6 carbon atoms, alkoxy of 1-6 carbon atoms, aryloxy; arylalkoxy, nitro, amino, NR2R2a, NR2COR2a, cycloalkylamino of 3-8 carbon atoms, morpholino, alkylsulfanyl of 1-6 carbon atoms, arylsulfanyl, pyridylsulfanyl, 2-N,N-dimethylaminoethylsulfanyl, —OCH2CO2R2bor —COR2c; Z1and Z2are each, independently, hydrogen, halogen, CN, alkyl of 1-6 carbon atoms, aryl, aralkyl of 6-12 carbon atoms, cycloalkyl of 3-8 carbon atoms, nitro, amino, —NR1R1a, —NR1COR1a, cycloalkylamino of 3-8 carbon atoms, morpholino, or OR8, or Z1and Z2may be taken together as a diene unit having the formula —CH═CR9—CR10═CR11—; or a pharmaceutically acceptable salt thereof, which are useful in treating metabolic disorders related to insulin resistance or hyperglycemia.
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- 8-hydroxy-7-substituted quinolines as anti-viral agents
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The present invention provides for 8-hydroxy-7-substituted quinoline compounds such as formula III These compounds are useful as anti-viral agents. Specifically, these compounds have anti-viral activity against the herpes virus, cytomegalovirus (CMV). Many of these compounds are also active against other herpes viruses, such as the varicella zoster virus, the Epstein-Barr virus, the herpes simplex virus and the human herpes virus type 8 (HHV-8).
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- Benzimidazole inhibitors of fructose 1,6-bisphosphatase
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Novel benzimidazole compounds of the following structure and their use as fructose-1,6-bisphosphatase inhibitors is described
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- Pyrrolopyrimidines and processes for the preparation thereof
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PCT No. PCT/EP96/02728 Sec. 371 Date Jan. 26, 1998 Sec. 102(e) Date Jan. 26, 1998 PCT Filed Jun. 24, 1996 PCT Pub. No. WO97/02266 PCT Pub. Date Jan. 23, 1997Described are 7H-pyrrolo[2,3-d]pyrimidine derivatives of formula I wherein the symbols are as defined in claim 1. Those compounds inhibit tyrosine protein kinase and can be used in the treatment of hyperproliferative diseases, for example tumour diseases.
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- Amino acid derivative anticonvulsant
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The present invention relates to compounds of the formula STR1
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- Amino acid derivative anticonvulsant
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The present invention relates to compounds exhibiting central nervous system (CNS) activity which are useful in the treatment of epilepsy and other CNS disorders. The compounds of this invention have the following general formula: STR1 and pharmaceutically acceptable salts thereof.
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- Phosphane-Tetrahalodiborane(4) Adducts: Formation of closo-3,4,5,6-Tetrabromo-1,2-diphosphahexaborane(4)
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Tetrabromodiborane(4), B2Br4, forms a 1:2 adduct 1 with PBr3, which reacts at 350 deg C to closo-1,2-P2B4Br4 (4a) in 25percent yield.Compound 4a neither rearranges to the 1,6-isomer nor decomposes to an appreciable extent upon heating to 650 deg C.B2Cl4 reacts with equimolar amounts of either tris(trimethylsilyl)phosphane or 1,2-bis(dichlorophosphanyl)ethane to give B2Cl4*P(SiMe3)3 (2) and B2Cl4*Cl2PCH2CH2PCl2 (3), respectively.Compound 2 represents the first phosphane-diborane(4) monoadduct with two boron atoms in different coordination environment.Key Words: Bis(tribromophosphane)-tetrabromodiborane(4) diadduct / closo-3,4,5,6-Tetrabromo-1,2-phosphahexaborane(4)
- Keller, Willi,Sneddon, Larry G.,Einholz, Wolfgang,Gemmler, Armin
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p. 2343 - 2346
(2007/10/02)
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- Reactivity of the diboron tetrahalides. Diboration of ethylene with diboron tetrabromide and thermal decomposition and ligand exchanges of diboron tetrabromide and diboron tetrachloride in carbon tetrabromide and carbon tetrachloride
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In contrast to previous assertions, we find that B2Br4 reacts readily with ethylene to generate BBr2CH2CH2BBr2, which can be isolated in 95% yield. While it has been reported numerous times that the disproportionation of B2Cl4, which eventually yields BCl3 and the polyhedral boron halides BnXn (n = 8-12), is slowed by the addition of haloalkenes, we have found that the disproportionation rate of both B2Cl4 and B2Br4 is also significantly decreased by the addition of the haloalkanes CBr4 and CCl4, For example, in the presence of a 7-fold excess of CBr4, the amount of B2Br4 recovered after 198 h at 96°C corresponded to 65% of that originally present. Although less dramatic, significant retardation of the B2Cl4 and B2Br4 disproportionations has also been observed when CCl4 was added. These results are interpreted in terms of the transient formation of (dihaloboryl)alkanes, a proposal that is buttressed by the observation of C(BBr2)4 and partially chlorinated (dihaloboryl)methanes like C(BBrCl)4 which were identified by mass spectrometry. The reaction between B2Br4 and excess CCl4 generates B2Cl4 in 84% yield, but the interaction of B2Cl4 with excess CBr4 does not appear to be an effective route to B2Br4.
- Ahmed,Castillo,Saulys,Morrison
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p. 706 - 710
(2008/10/08)
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- Reactions of the diboron tetrahalides B2Cl4 and B2Br4 with B5H9: Preparation and properties of the (dihaloboryl)pentaborane derivatives 1-BX2B5H8, (X = Br, Cl, F, OCH3, t-Bu, H) and synthesis of (BCl2)3B5H6
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The reactions of B2Cl4 with excess B5H9 yield 1-BCl2B5H8 (73%) while those of B2Br4 generate 1-BBr2B5H8 (80%). Ligand exchange of 1-BCl2B5H8 with excess BBr3 forms 1-BBr2B5H8 (86%), that with Hg(CF3)2 results in 1-BF2B5H8 (96%), that with CH3OH generates 1-B(OCH3)2B5H8 (46%), and that with Li(t-Bu) prepares B(t-Bu)(Cl)B5H8 (23%) and B(t-Bu)2B5H8 (20%). The relative thermal stabilities of these products are BF2B5H8 > BCl2B5H8 > BBr2B5H8 > B(OCH3)2B5H8 > B(t-Bu)2B5H8. All of these BX2B5H8 compounds (X = F, Cl, OCH3, t-Bu) decompose to form BX3 and B5H9 as the volatile products. Reactions of BCl2B5H8 with excess B2Cl4 yield (BCl2)3B5H6, a compound of limited thermal stability, but no evidence for further BCl2 substitution on the pentaborane cage was obtained. Reductions of BCl2B5H8 with LiBH4 in C6H5Cl or C6H4Cl2 form apparent equilibrium mixtures of 1:1′,2′-[B5H8][B2H5] and 1:1′-[B5H8][B2H5]. One or both of these compounds decompose with the evolution of B2H6, B5H9, and coupled pentaborane cages (B5H7)n, where n can be at least as large as 8. The 11B NMR and mass spectrometric evidence from the last reaction is consistent with the initial dimerization of the hexaborane 1-BH2B5H8, which is rapidly followed by the formation of 1:1′-[B5H8][B2H5], the cross product arising from the interaction of B2H6 with (BH2B5H8)2, and then isomerization of this heptaborane to 1:1′,2′-[B5H8][B2H5].
- Saulys,Morrison
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p. 4174 - 4179
(2008/10/08)
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- Fluorination of boron chlorides and boron bromides by reaction with bis(trifluoromethyl)mercury, trichlorofluoromethane, or tribromofluoromethane: Synthesis of BF2B5H8
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The interaction of BCl3 with excess CFCl3 has been examined by 11B and 19F NMR. Although small amounts of BFCl2 and BF2Cl, 9% each, are observed after 283 h at 65°C, BF3 is not a major product. At 130°C, however, BF3 is formed in 89% yield after 33 h. Boron trifluoride is isolated in 98 and 97% yields from the reactions of BCl3 and BBr3, respectively, with CFBr3 at 130 °C. At ambient temperature, Hg(CF3)2 reacts with BCl3 and BBr3, generating BF3 in 99 and 98% yields, respectively. The reaction of B2Cl4 with excess CFCl3 was followed spectroscopically at 65, 90, and 130°C, and the 19F chemical shifts of the partially fluorinated diboron tetrahalides have been assigned. Diboron tetrafluoride was isolated from the reaction between B2Cl4 and CFBr3 in 89% yield, from B2Br4 and CFBr3 in 78% yield, and from B2Cl4 and Hg(CF3)2 in 89% yield. Within 45 min the reaction between 1-BCl2B5H8 and Hg(CF3)2 produces the new compound 1-BF2B5H8 in 96% yield. Tetraboron tetrachloride is by far the least reactive of the boron chlorides examined.
- Saulys,Castillo,Morrison
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p. 1619 - 1624
(2008/10/08)
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- Substituted aminobenzoates, their preparation and use
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Novel lower-alkyl 2-(hydroxyphenylamino)benzoates, useful as inhibitors of lipoxygenase, are of the formula STR1 wherein R is hydrogen, lower-alkyl or lower-alkoxy; R' is hydrogen or lower-alkyl; R" is hydrogen, lower-alkyl or halo; and Alk is lower-alkyl. The compounds are prepared by de-etherification of the corresponding alkyl or benzyl ethers.
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- Benzyl alcohol derivatives, their preparation and use
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Novel hydroxyphenylaminobenzenealkanols, useful as antiasthmatic agents, are of the formula STR1 wherein R is hydrogen, lower-alkyl, lower-alkoxy or halo; R' is hydrogen or lower-alkyl; R" is hydrogen, lower-alkyl or halo; and Y is Cn H2n wherein n is 1-2. The compounds are prepared by de-etherification of the corresponding phenol alkyl or benzyl ethers; by reduction of the corresponding benzoic acids or esters thereof; or by reduction of ketones wherein --Y--OH is replaced by --COCH3.
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- Process for 1-oxacephem derivatives
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A process for preparing compounds of the formula STR1 in which R is hydrogen or methoxy, R1 is a hydroxyl group, R2 is chlorine, bromine, OAc or SHET, R3 is hydrogen or a cleavable carboxy-protecting group preferably selected from loweralkyl, benzyl, benzhydryl, loweralkoxyloweralkyl, loweralkoxybenzyl, phenacyl, trimethylsilyl, 2,2,2-trichloroethyl or pivaloloxy, R4 is hydrogen or a cleavable amino-protecting acyl group, or R4 NH represents phthalimido, and HET is a five or six membered aromatic heterocycle containing 1-4 heteroatoms and optionally substituted with loweralkyl, and from which the corresponding 1-oxacephem derivatives can be prepared is described. The novel intermediate compounds of the formula 1 are produced from a penicillin derivative of formula 1 wherein R, R3 and R4 are as above described and R1 and R2 are both the same halogen, by treatment with a formylating agent in a halogenated hydrocarbon solvent to obtain the corresponding compound in which R1 and R2 are both OCHO which is then treated with less than one molar equivalent of a boron halide to obtain a 2:1 to 4:1 mixture of the corresponding compounds of formula 1 in which R1 is OCHO and R2 is the corresponding halogen or R1 is halogen and R2 is OCHO, and in which the former compound predominates. This mixture is separated and the compound in which R1 is OCHO and R2 is halogen is isolated. This last compound is hydrolyzed and the desired intermediate compound in which R1 is OH and R2 is a halogen is isolated. Alternatively, the compound of formula 1 in which R1 is OCHO and R2 is halogen is subjected to displacement by - OAc or HSHET prior to the hydrolysis.
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