- Regiospecific and highly stereoselective formation of benzisochroman-6,9-quinones. Synthesis of (±)-ventilagone and (±)-ventiloquinone H
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An approach known to give regiospecific cycloadditions over a wide range of substrates has been applied to the synthesis of (±)-ventilagone and (±)-ventiloquinone H using a novel, electron-rich heterocyclic diene. The strategy provides for the sole format
- Blouin,Beland,Brassard
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Read Online
- Derivatives of m-Guaiacol, Their Preparation and Their Uses
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The invention concerns derivatives of m-guaiacol, their preparation and their uses as biocides, in particular as antibacterials or disinfectants.
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Paragraph 0125; 0141
(2021/11/05)
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- Tuning the Reactivity of Peroxo Anhydrides for Aromatic C-H Bond Oxidation
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Phenol moieties are key structural motifs in many areas of chemical research from polymers to pharmaceuticals. Herein, we report on the design and use of a structurally demanding cyclic peroxide (spiro[bicyclo[2.2.1]heptane-2,4′-[1,2]dioxolane]-3′,5′-dione, P4) for the direct hydroxylation of aromatic substrates. The new peroxide benefits from high thermal stability and can be synthesized from readily available starting materials. The aromatic C-H oxidation using P4 exhibits generally good yields (up to 96%) and appreciable regioselectivities.
- Pilevar, Afsaneh,Hosseini, Abolfazl,?ekutor, Marina,Hausmann, Heike,Becker, Jonathan,Turke, Kevin,Schreiner, Peter R.
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p. 10070 - 10079
(2018/09/06)
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- A scalable synthesis of CE-157119 HCl Salt, an SRI/5-HT2A antagonist
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A scalable synthesis of CE-157119 HCl salt (1), an SRI/5-HT2A antagonist, was developed via the regioselective SNAr etherification between a phenol and an N-methylamide. This early development route shortened the original 5-step synt
- Tao, Yong,Widlicka, Daniel W.,Hill, Paul D.,Couturier, Michel,Young, Gregory R.
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p. 1805 - 1810
(2013/01/15)
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- IMIDAZOLIDINEDIONE DERIVATIVES
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The invention provides a compound of formula (Ia), and pharmaceutically acceptable salts thereof. The invention also provides use of the compounds or salts as modulators of Kv3.1 and/or Kv3.2, and in the treatment of diseases or disorders where a modulator of Kv3.1 and/or Kv3.2 is required, such as depression and mood disorders, hearing disorders, schizopherenea, substance abuse disorders, sleep disorders or epilepsy.
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- Microwave-assisted cleavage of aryl methyl ethers with lithium thioethoxide (LiSEt)
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Lithium thioethoxide (LiSEt), a white solid easily prepared from EtSH and n-BuLi in hexane, was identified as a highly efficient reagent for the cleavage (O-demethylation) of aryl methyl ethers, i.e. methyl-protected phenols. Of particular synthetic value are applications in the double deprotection of 1,2-dimethoxyarenes (to give catechols) and in the selective monodeprotection of di- and trimethoxyarenes. The thermal reactions, which are usually performed in DMF as a solvent, can be greatly accelerated through microwave irradiation. In this case, the monodemethylated products are usually formed in high (80-99%) yield within only 15 minutes.
- Cvengro?, Ján,Neufeind, Stefan,Becker, Anne,Schmalz, Hans-Günther
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experimental part
p. 1993 - 1998
(2009/04/07)
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- SYNTHESIS OF THERAPEUTIC DIPHENYL ETHERS
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This invention is directed to a method of synthesizing compounds of Formula I and to intermediates useful in the synthesis of compounds of Formula I wherein X, Y, R1, R2, R3, and R4 are as defined herein above.
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Page/Page column 3-4; 6
(2008/06/13)
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- Lewis Acid-Directed Reactions of Quinones with Styrenyl Systems: The Case of 2-Methoxy-3-methyl-1,4-benzoquinone
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Reactions of 2-methoxy-3-methyl-1,4-benzoquinone with various (E)-1-propenylbenzenes promoted by 1 equiv of Ti(IV), as a 1:1 mixture of TiCl4-Ti(O-i-Pr)4, produce rel-(1S,6R,7R,8R)-8-aryl-4,7-dimethyl-3-methoxybicyclo[4.2.0]oct-3-ene-2,5- diones 3 and trans-2-aryl-3,7-dimethyl-6-methoxy-2,3-dihydro-5-benzofuranols 5 as the major products. Reactions promoted by 2 equiv of Ti(IV) as a 1:1 mixture of TiCl4-Ti(O-i-Pr)4 or 1 equiv of either TiCl4, SnCl4, or BF3·OEt2 give regioisomeric rel-(1R,6S,7A,8R)-7-aryl-4,8-dimethyl-3-methoxybicyclo[4.2.0]oct-3-ene-2,5- diones (4) and/or trans-2-aryl-3,6-dimethyl-7-methoxy-2,3-dihydro-5-benzofuranols (6). A mechanism involving regioselective coordination of the various Lewis acids to the quinone is used to explain the formation of the products. These reactions demonstrate the effective regiocontrol exerted over the reactions by the nature of the Lewis acid promoters. Cyclobutanes 3 and 4 cleanly undergo rearrangement to the corresponding benzofuranols 5 and 6 on treatment with protic acid. In contrast, reactions of 2-methoxy-1,4-benzoquinone promoted by either BF3·OEt2 or Ti(IV), as 1 equiv or excess amounts of TiCl4 or 1:1 TiCl4-Ti(O-i-Pr)4, all afford the same regioisomeric products, i.e., rel-(1S,6R,7R,8R)-8-aryl-7-methyl-3-methoxybicyclo[4.2.0]oct-3-ene-2,5-dione 25 and/or trans-2-aryl-3-methyl-6-meth-oxy-2,3-dihydro-5-benzofuranol 27.
- Engler, Thomas A.,Iyengar, Rajesh
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p. 1929 - 1934
(2007/10/03)
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- Regioselectivity in the Reductive Cleavage of Pyrogallol Derivatives: Reductive Electrophilic Substitution of Acetals of 2,3-Dimethoxyphenol
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Acetals of 2,3-dimethoxyphenol were used as the starting materials for the transformation of 1,2,3-trioxygenated benzenes into various 1-oxygenated-2,3-dicarbon-substituted benzenes, via regioselective reductive electrophilic substitution of the 2-methoxy
- Azzena, Ugo,Melloni, Giovanni,Pisano, Luisa
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p. 261 - 266
(2007/10/02)
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- Ultrasound-promoted synthesis of substituted phenanthrene-1,4-quinones; the structure of plectranthon D
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A series of tanshinone-type diterpenoids was prepared by ultrasound-promoted and Lewis acid catalyzed, highly regioselective cycloadditions of styrenes with substituted 1,4-benzoquinones as the key step.
- Zhang, Zhao-Rong,Flachsmann, Felix,Moghaddam, Firouz Matloubi,Rueedi, Peter
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p. 2153 - 2156
(2007/10/02)
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- Reductive Electrophilic Substitution of Pyrogallol Derivatives: Synthesis of 2,3-Disubstituted Phenols
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1,2-Dimethoxy-3-methoxymethoxybenzene, 1, was used as the starting material for the transformation of a 1,2,3-trioxybenzene into various 1-oxy-2,3-dicarbobenzenes, via regioselective reductive electrophilic substitution of the 2-methoxy group followed by
- Azzena, Ugo,Melloni, Giovanni,Pisano, Luisa
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p. 5635 - 5638
(2007/10/02)
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- A convenient, practical synthesis of substituted resorcinols: Synthesis of DB-2073 and olivetol
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A wide variety of easily accesible 1,3-cyclohexanediones are readily transformed to substituted dimethyl resorcinols with iodine and methanol.
- Kotnis, Atul S.
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p. 3441 - 3444
(2007/10/02)
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- Potential Antisecretory Antidiarrheals. 2. α2-Adrenergic 2-imidazolines
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Lofexidine, an α2-agonist, has central hypotensive activity and peripheral intestinal antisecretory activity.Analogues were synthetsized with increased polarity in an attempt to prevent penetration of the blood-brain barrier.The compounds were evaluated in the cholera toxin treated ligated jejunum of the rat and in the Ussing chamber with a rabbit ileum preparation.Active compounds were determined to be α2-adrenergic agonists by yohimbine reversals of their Ussing chamber activities.The 2,6-dimethyl derivative of lofexidine, 4a, was as active as lofexidine invivo, but derivatives with 2,6-substituents larger than ethyl were inactive. (Aryloxy)alkyl derivatives which have an imidazoline and a methyl or larger group as part of the alkyl exhibited the best antisecretory activity.Compounds with substituents in the para position of the phenyl ring were generally inactive. 3-Amino-2,6-dimethyl derivative 21 was twice as active as 4a.A 2-methyl substituent is required in the 3-amino series to retain good activity. 2-methyl derivative 12a had activity comparable to that of 4a, while 6-methyl derivative 12f was inactive.Substituents on the 3-amino group did not affect the activity, but substituting a hydroxyl for the amino group produced an inactive compounds.Replacing the phenyl moiety with a 4-indole resulted in retention of activity, but other heterocycles were inactive.Compound 12a was resolved and d isomer 32 was five times more potent than l isomer 33.The more active compounds in the rat cholera toxin assey (RCTA), when evaluated in the dog, exhibited antisecretory activity but also exhibited centaral nervous system (CNS) effects, sedation and ataxia, at 10 mg/kg, and in spontaneouslyhypertensive rats at 50 mg/kg.A measure of polarity, log P, was calculated for the (aryloxy)alkyl groups.Regression analysis showed no correlation of antisecretory ED50 to the calculated log P.The active compounds did not show a separation of the central CNS effects from the peripheral antisecretory activity by increasing the polarity.
- Moormann, Alan E.,Pitzele, Barnett S.,Jones, P. H.,Gullikson, Gary W.,Albin, David,et al.
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p. 614 - 626
(2007/10/02)
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- AROMATISIERUNG VON CYCLOHEXENON-DERIVATEN UEBER SELENORGANISCHE ZWISCHENSTUFEN
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Reaction of the hydroaromatic compounds (1a) and (3a) with lithiumdiisopropylamide followed by phenylselenyl chloride gives the selenides (1b) and (1c) resp. (3b), which form exclusively the phenols (4) resp. (6) after oxidation with 3-chloroperbenzoic acid in the presence of 3,5-dimethoxyaniline (7a).
- Tietze, Lutz-F.,Kiedrowski, Guenter v.,Berger, Bernhard
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