- Method for preparing 6-bromotriphenylphosphonio-n-caproic acid
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The invention relates to the field of production and preparation of compounds and particularly relates to a method for preparing 6-bromotriphenylphosphonio-n-caproic acid. The method comprises the following steps: (1) subjecting caprolactam to a hydrolysis reaction, so as to prepare 6-aminocaproic acid; (2) subjecting 6-aminocaproic acid to a diazotization reaction, so as to prepare 6-hydroxycaproic acid; (3) subjecting 6-hydroxycaproic acid to a bromization reaction, so as to prepare 6-bromocaproic acid; and (4) enabling 6-bromocaproic acid to react with triphenyl phosphine, thereby obtaining 6-bromotriphenylphosphonio-n-caproic acid.
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Paragraph 0048-0055; 0056-0063; 0064-0071; 0072-0079
(2017/08/29)
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- Synthesis of polysiloxane-based quaternized imidazolium salts with a hydroxy group at the end of alkyl groups
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A series of polysiloxane derivatives having quaternized imidazolium moieties with hydroxyalkyl groups ([HPImnOH]Xs) (where n is the number of methylene group and X is counter anion) were prepared by quaternization of poly(3-chloropropylmethylsiloxane) (P1) using 1-(ω-hydroxyalkyl)imidazole derivatives (ImnOHs) and anion-exchange reaction using lithium bis(trifluoromethanesulfonyl)imide. Polysiloxane-based quaternized imidazolium salts having hydroxyalkyl groups with chloride anion ([HPImnOH]Cls) were obtained with high quaternization ratio of approximately 100 mol%. The glass transition temperatures (Tgs) of [HPImnOH]Xs were reduced by introducing a hydroxy group at the end of alkyl groups; however, no significant reduction in Tgs was observed by anion exchange from chloride anion to bis(trifluoromethanesulfonyl)imide one (Tf2N-).
- Ichikawa, Tsukasa,Wako, Tsuyoshi,Nemoto, Nobukatsu
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- DMF-mediated deprotection of bulky silyl esters under neutral and fluoride-free conditions
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Bulky TBDPS and TIPS carboxylic esters were efficiently cleaved by a green and mild protocol using only DMF-H2O (20:1) at 70 °C. The neutral conditions tolerate various common acid- and base-labile functionalities, including alkyl and aryl silyl ethers.
- Chen, Bo,Sun, Hui-Xia,Qin, Jian-Feng,Wang, Bing
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p. 253 - 255
(2016/01/12)
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- Design, synthesis and antimycobacterial activities of 1-methyl-2-alkenyl- 4(1H)-quinolones
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A series of 23 new 1-methyl-2-alkenyl-4(1H)quinolones have been synthesized and evaluated in vitro for their antimycobacterial activities against fast growing species of mycobacteria, such as Mycobacterium fortuitum, M. smegmatis and M. phlei. The compounds displayed good to excellent inhibition of the growth of the mycobacterial test strains with improved antimycobacterial activity compared to the hit compound, evocarpine. The most active compounds, which possessed chain length of 11-13 carbons at position-2 displayed potent inhibitory effects with an MIC value of 1.0 mg/L. In a human diploid embryonic lung cell line, MRC-5 cytotoxicity assay, the alkaloids showed weak to moderate cytotoxic activity. Biological evaluation of these evocarpine analogues on the less pathogenic fast growing strains of mycobacteria showed an interesting antimycobacterial profile and provided significant insight into the structure-activity relationships.
- Wube, Abraham A.,Hüfner, Antje,Thomaschitz, Christina,Blunder, Martina,Kollroser, Manfred,Bauer, Rudolf,Bucar, Franz
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experimental part
p. 567 - 579
(2011/03/17)
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- A new phenylethyl alkyl amide from the Ambrostoma quadriimpressum Motschulsky
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A new phenylethyl alkyl amide, (10R)-10-hydroxy-N-phenethyloctadecanamide (1), was isolated from the beetle Ambrostoma quadriimpressum Motschulsky. The structure of the amide was determined by NMR and MS. The absolute configuration of compound 1 was confirmed by an asymmetric total synthesis, which was started from L-glutamic acid. The construction of the aliphatic chain was accomplished by the selective protection of the hydroxy groups and two-time implementation of the Wittig olefination reaction.
- Zhao, Guolei,Yang, Chao,Li, Bing,Xia, Wujiong
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p. 1342 - 1346
(2011/11/14)
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- Fluoroalkene modification of mercaptoacetamide-based histone deacetylase inhibitors
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Inhibitors of histone deacetylases (HDAC) are emerging as a promising class of anti-cancer agents. The mercaptoacetoamide-based inhibitors are reported to be less toxic than hydroxamate and are worthy of further consideration. Therefore, we have designed a series of analogs as potential inhibitors of HDACs, in which the mercaptoacetamide group was replaced by (mercaptomethyl)fluoroalkene, and their HDAC inhibitory activity was evaluated. Subnanomolar inhibition was observed for all synthetic compounds.
- Osada, Satoshi,Sano, Satoshi,Ueyama, Mariko,Chuman, Yoshiro,Kodama, Hiroaki,Sakaguchi, Kazuyasu
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experimental part
p. 605 - 611
(2010/05/02)
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- Hypervalent λ3-bromane strategy for Baeyer-Villiger oxidation: Selective transformation of primary aliphatic and aromatic aldehydes to formates, which is missing in the classical Baeyer-Villiger oxidation
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A conceptually distinct, modern strategy for Baeyer-Villiger oxidation (BVO) was developed. Our novel method involves initial hydration of water to carbonyl compounds, followed by ligand exchange of hypervalent aryl-λ3-bromane on bromane(III) with the resulting hydrate, yielding a new type of activated Criegee intermediate. The intermediate undergoes BV rearrangement and produces an ester via facile reductive elimination of an aryl-λ3-bromanyl group, because of the hypernucleofugality. The novel strategy makes it possible to induce selectively the BV rearrangement of straight chain primary aliphatic as well as aromatic aldehydes, which is missing in the classical BVO: for instance, octanal and benzaldehyde afforded rearranged formate esters with high selectivity (>95%) under our conditions, while the attempted classical BVO produced only carboxylic acids. This firmly establishes the powerful nature of new methodology for BVO.
- Ochiai, Masahito,Yoshimura, Akira,Miyamoto, Kazunori,Hayashi, Satoko,Nakanishi, Waro
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supporting information; experimental part
p. 9236 - 9239
(2010/11/02)
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- A new one-pot synthetic method for selenium-containing medium-sized α,β-unsaturated cyclic ketones
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The reaction of tetrahydroselenopyran-2-one (7) with ethynyllithiums 20a-h, followed by treatment with aqueous 5% H2SO4 successfully led to a two-carbon ring expansion to give the 2-substituted 5,6,7,8-tetrahydroselenocin-4-ones 21a-h in 43-95% yields. Seven- to nine-membered γ-selena-α,β-unsaturated cyclic ketones 22-26 and a 5,6,7,8-tetrahydrotellurocin-4-one 27 were also prepared from the corresponding selenolactones or tellurolactone in a one-pot reaction.
- Sashida, Haruki,Nakayama, Akemi,Kaname, Mamoru
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experimental part
p. 3229 - 3236
(2009/05/07)
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- METHODS AND MATERIALS FOR PREPARING ORGANIC COMPOUNDS FROM PRIMARY AMINES
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Methods are disclosed for the conversion of primary amines to other functional groups. The methods can be used to prepare chiral organic compounds, including organic alcohols and organic halides. The methods can be carried out by treating a primary amine with an activating agent and a nitrosyl agent to produce the transformed compound along with nitrous oxide.
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Page/Page column 21; 27-28
(2008/06/13)
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- Synthesis and transdermal permeation-enhancing activity of ketone, amide, and alkane analogs of Transkarbam 12
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Transkarbam 12 (5-(dodecyloxycarbonyl)pentylammonium-5-(dodecyloxycarbonyl) pentylcarbamate, T12) is a highly active transdermal permeation enhancer. In this study, ketone, amide, and alkane analogs of T12 have been synthesized and evaluated for their permeation-enhancing activity using porcine skin and theophylline as a model drug. Replacement of ester by methylene and ketone, respectively, led to a significant decrease of activity. Amide analogs displayed lower activity in 60% propylene glycol and were comparable to T12 in isopropyl myristate. An intramolecular H-bond between ester and ammonium-carbamate group was suggested to be important for the permeation-enhancing activity of T12.
- Holas, Tomas,Vavrova, Katerina,Klimentova, Jana,Hrabalek, Alexandr
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p. 2896 - 2903
(2007/10/03)
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- Influence of terminal branching on the transdermal permeation-enhancing activity in fatty alcohols and acids
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In order to investigate the effect of terminal chain branching in the skin permeation enhancers, seven alcohols and seven acids with the chain length of 8-12 carbons and terminal methyl or ethyl branching were prepared. Their transdermal permeation-enhancing activities were evaluated in vitro using theophylline as a model permeant and porcine skin, and compared to those of the linear standards. Terminal methyl branching increased the enhancing activity only in 12C acid, no effect was seen in the shorter ones. Terminal ethyl however produced a significant increase in activity. In the alcohols, the branching was likely to change the mode of action, due to a different relationship between the activity and the chain length.
- Klimentova, Jana,Kosak, Petr,Vavrova, Katerina,Holas, Tomas,Hrabalek, Alexandr
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p. 7681 - 7687
(2007/10/03)
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- Dispiro-1,2,4-trioxane analogues of a prototype dispiro-1,2,4-trioxolane: Mechanistic comparators for artemisinin in the context of reaction pathways with iron(II)
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Single electron reduction of the 1,2,4-trioxane heterocycle of artemisinin (1) forms primary and secondary carbon-centered radicals. The complex structure of 1 does not lend itself to a satisfactory dissection of the electronic and steric effects that influence the formation and subsequent reaction of these carbon-centered free radicals. To help demarcate these effects, we characterized the reactions of achiral dispiro-1,2,4-trioxolane 4 and dispiro-1,2,4-trioxanes 5-7 with ferrous bromide and 4-oxo-TEMPO. Our results suggest a small preference for attack of Fe(II) on the nonketal peroxide oxygen atom of 1. For 4, but not for 5 and 6, there was a strong preference for attack of Fe(II) on the less hindered peroxide bond oxygen atom. The steric hindrance afforded by a spiroadamantane in a five-membered trioxolane is evidently much greater than that for a corresponding six-membered trioxane. Unlike 1, 5-7 fragment by entropically favored β-scission pathways forming relatively stable α-oxa carbon-centered radicals. These data suggest that formation of either primary or secondary carbon-centered radicals is a necessary but insufficient criterion for antimalarial activity of 1 and synthetic peroxides.
- Tang, Yuanqing,Dong, Yuxiang,Wang, Xiaofang,Sriraghavan, Kamaraj,Wood, James K.,Vennerstrom, Jonathan L.
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p. 5103 - 5110
(2007/10/03)
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- Derivatised molecules for mass spectrometry
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Compounds of formula (IIa): are provided where:X is a group capable of being cleaved from the α-carbon atom to form an ion of formula (I')C is a carbon atom bearing a single positive charge or a single negative charge; The invention further provides compounds of formula (IIb): where:X is a counter-ion to C. The compounds of formula (IIa) and (IIb) may form ions of formula (I') by either cleaving the C-X bond between X and the α-carbon atoms in the case of the compounds of formula (IIa) or dissociating X in the case of compounds of formula (IIb).
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- Asymmetric synthesis of unnatural (Z,Z,E)-octadecatrienoid and eicosatrienoid by lipoxygenase-catalyzed oxygenation
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The asymmetric synthesis of unnatural 13-hydroxy-(6Z,9Z,11E,13S)-octadecatrienoid and 15-hydroxy-(8Z,11Z,13E,15S)-eicosatrienoid is described using a biomimetic oxidation route. The main highlights of this synthesis are the asymmetric hydroxylation of the substrate with soybean lipoxygenase and cis selective Wittig olefination.
- Nanda,Yadav
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p. 1799 - 1806
(2007/10/03)
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- IBX-mediated oxidation of primary alcohols and aldehydes to form carboxylic acids
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Under mild conditions and without the use of toxic metals, the oxidation of primary alcohols and aldehydes to the corresponding carboxylic acids with 1-hydroxy-1,2-benziodoxole-3(1H)-one-1-oxide (IBX) proceeds in the presence of 1-hydroxypyridine or N-hydroxysuccinimide (see scheme). The reaction tolerates a wide variety of functional groups.
- Mazitschek, Ralph,Muelbaier, Marcel,Giannis, Athanassios
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p. 4059 - 4061
(2007/10/03)
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- Asymmetric synthesis of a cytotoxic amide of Telesto riisei
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An efficient synthesis of both the enantiomers of N-(2-phenylethyl)-8- hydroxypentadecacarboxamide using the cytotoxic principles of Telesto riisei has been formulated using cyclohexylideneglyceraldehyde 1 as the chiral template. A non-stereoselective Grignard addition to the aldehyde 1 gave the C-3 epimers of the required chiron, 3-alkylglycerol which were converted to the title compound via a standard sequence of reactions.
- Sankaranarayanan, Sivaraman,Chattopadhyay, Subrata
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p. 1345 - 1350
(2007/10/03)
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- "Mercaptan-Tail" Porphyrins: Synthetic Analogues for the Active Site of Cytochrome P-450
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The synthesis and characterization of a series of tetraarylporphyrins which bear covalently attached alkyl and aryl mercaptans designed to serve as axial ligands are described.The coordination chemistry of the iron(II) complexes of these "mercaptan-tail" porphyrins has been investigated by 1H NMR, IR, and electronic absorption spectroscopy, magnetic circular dichroism, and magnetic susceptibility measurements.Ferrous complexes of the alkyl mercaptan-tail porphyrins appear to remain four-coordinate, intermediate spin (S = 1) in solution.The situation is less clear in the case of appended aryl mercaptans and a "tail-on/tail-off" equilibrium is implicated.In the presence of carbon monoxide, however, binding of thiol trans to CO is observed in both the alkyl and aryl cases.By the addition of an appropriate base, six-coordinate mercaptide-Fe(II)-CO complexes can be generated; these reproduce quite well the characteristic absorption and MCD spectra of cytochrome P-450, suggesting that such compounds are indeed viable models for the active site of cytochrome P-450.
- Collman, James P.,Groh, Susan E.
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p. 1391 - 1403
(2007/10/02)
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- Preparation of Macrocyclic Lactones by Ring Closure of Cesium Carboxylates
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A series of ω-halo fatty acids, the longest being 16-iodohexadecanoic acid, was prepared by oxidation of the corresponding ketones with m-chloroperbenzoic acid in boiling chloroform, followed by ring opening usually with hydrogen iodide in acetic acid at 100 deg C.Solutions of these acids in dimethylformamide (DMF) at concentrations of 5E-3 - 5E-2 M were treated with an equivalent amount of dry Cs2CO3.The solutions were stirred at 40 deg C overnight.Workup of the reaction mixture produced a mixture of (macro)cyclic lactone (macrolide) and its dimer (dilide).For the case of 16-iodohexanoic acid the lactone was isolated in 85percent yield.Yields for other large ring macrolides were also excellent.It was demonstrated that substitution by carboxylate on a secondary halide also goes well to afford the corresponding macrolide with no detectable amount of elimination.The effects of ring size, concentration, and solvent on the ring closure of the cesium carboxylates formed in situ were investigated.DMF is the best solvent of those investigated for the ring closure.Cesium carboxylates also undergo more readily ring closure and in far better yield than the carboxylates of lithium, sodium, potassium, rubidium, silver, thallium, magnesium, strontium, or barium.The S-lactone of ricinelaidic acid was prepared optically pure in 80percent yield from optically pure mesylate of R-ricinelaidic acid, which was treated with cesium carbonate in dry DMF.This demonstrates that the ring closure proceeds with the anticipated SN2 inversion at the hydroxyl-bearing carbon atom.With the same approach optically pure S-zearalenone was protected and subjected to ring opening, and the hydroxyl group was activated as mesylate.Some racemization was found to occur in the ring-opening step.On treatment of this material with dry cesium carbonate in DMF, the desired ring closure took place in 80percent yield to provide an excess of the protected R enantiomer of zearalenone.On the basis of these results, some speculations are made concerning the action of cesium in promoting ring closure to macrocyclic lactones.
- Kruizinga, Wim H.,Kellogg, Richard M.
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p. 5183 - 5189
(2007/10/02)
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- Process for the production of even series ω-amino acids
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The invention relates to a process for the production of even-series ω-amino acids of the general empirical formula NH2 (CH2 CH2)n CH2 COOH /I/, where N = 1 or 2. The process of the invention comprises telomerizing ethylene with methyl esters of halogen acetic acids of the general empirical formula Xm CH3-m COOCH3 /II/, where X = Br and m = 1 or X = Cl and m = 2 or 3, at a temperature of from 100 to 145° C. and under ethylene pressure of from 25 to 40 gage atmospheres in the presence of initiators of free-radical reactions. The telomerization procedure gives telomers of the general empirical formula CH3 OOCCH3-m Xm-1 (CH2 CH2)n X /III/, where X, n and m are as in formulas /I/ and /II/. In case X = Br and m = 1, the telomers described by formula /III/ are subjected to ammonolysis with ammonia at a temperature of about 100° C to yield ammonolysis products; whereas, in case X = Cl and m = 2 or 3, the telomers described by formula /III/ are reduced to telomers of the same general formula, where X = Cl and m = 1, and the latter are subjected to ammonolysis with ammonia at a temperature from 135° to 140° C to yield ammonolysis products. Then the ammonolysis products are hydrolyzed with hydrochloric acid at a temperature of from 80° to 90° C., and the desired product is recovered from the resultant hydrolyzate by use of a styrene-divinylbenzene sulfocationite resin in the H form. The foregoing process uses widely available industrial raw materials, proceeds by a straightforward route and requires simple equipment; it is further characterized by high yields at all steps; all unreacted feedstocks can be completely recycled; and no non-utilizable wastes are produced.
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