- Kinetics of the reaction of N,N-dimethylaniline with 1-bromoalk-2-ynes
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Quaternization of N,N-dimethylaniline with propargyl bromide, 1-bromobut-2-yne, and 1-bromooct-2-yne were studied. It was shown that, with the lengthening chain of the substituent at the triple bond, the quaternization rate tends to increase.
- Andreev,Ryzhakov,Sobolev
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- Trimethylhalosilane elimination from trimethylsilylsubstituted gem-dihalocyclopropanes
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The aluminum halide-catalyzed elimination of trimethylhalosilane from 1,1-dihalo-2-(trimethylsilyl)cyclopropanes (XCl and Br) resulted in the formation of propargyl halides, HCCCH2X. Reaction of 1,1-dichloro-2,2-dimethyl-3-(trimethylsilyl) cyclopropane with sodium ethoxide in ethanol also resulted in elimination of trimethylchlorosilane; the organic product was 3-ethoxy-3-methyl-1-butyne, HCCCMe2OEt, and a mechanism involving β-elimination of trimethylchlorosilane to give 1-chloro-3,3-dimethylcyclopropene and reaction of the latter to produce the acetylenic ether is suggested.
- Seyferth, Dietmar,Jula, Theodore F.
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- Anti-AIDS agents. Part 62: Anti-HIV activity of 2′-substituted 4-methyl-3′,4′-di-O-(-)-camphanoyl-(+)-cis-khellactone (4-methyl DCK) analogs
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Four 4-methyl-3′,4′-di-O-(-)-camphanoyl-(+)-cis-khellactone (4-methyl DCK) analogs (7a-d) with different alkyl substituents at the 2′-position were synthesized and evaluated for inhibition of HIV-1 replication in H9 lymphocytes. 2′-Methyl-2′-ethyl-4-methyl DCK (7b) was more potent (EC50 = 0.22 μM, TI > 175) than the other three compounds (7a, 7c, and 7d), but significantly less potent than 4-methyl DCK (2, EC50 = 0.0059 μM, TI > 6600). Four 4-methyl-3′,4′- di-O-(-)-camphanoyl-(+)-cis-khellactone (4-methyl DCK) analogs (7a-d) with different alkyl substituents at the 2′-position were synthesized and evaluated for inhibition of HIV-1 replication in H9 lymphocytes. 2′-Methyl-2′-ethyl-4-methyl DCK (7b) was more potent (EC 50 = 0.22 μM, TI > 175) than the other three compounds (7a, 7c, and 7d), but significantly less potent than 4-methyl DCK (2, EC50 = 0.0059 μM, TI > 6600). The bioassay results indicated that the 2′-substituents had a strong effect on the anti-HIV activity, and gem-dimethyl substitution at the 2′-position was greatly preferable to larger alkyl substituents or hydrogen atoms.
- Zhang, Qian,Chen, Ying,Xia, Peng,Xia, Yi,Yang, Zheng-Yu,Yu, Donglei,Morris-Natschke, Susan L.,Lee, Kuo-Hsiung
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- Regiospecific Synthesis of Calcium-Independent Daptomycin Antibiotics using a Chemoenzymatic Method
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Daptomycin (DAP) is a calcium (Ca2+)-dependent FDA-approved antibiotic drug for the treatment of Gram-positive infections. It possesses a complex pharmacophore hampering derivatization and/or synthesis of analogues. To mimic the Ca2+-binding effect, we used a chemoenzymatic approach to modify the tryptophan (Trp) residue of DAP and synthesize kinetically characterized and structurally elucidated regiospecific Trp-modified DAP analogues. We demonstrated that the modified DAPs are several times more active than the parent molecule against antibiotic-susceptible and antibiotic-resistant Gram-positive bacteria. Strikingly, and in contrast to the parent molecule, the DAP derivatives do not rely on calcium or any additional elements for activity.
- Mupparapu, Nagaraju,Lin, Yu-Hsin Cindy,Kim, Tae Ho,Elshahawi, Sherif I.
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supporting information
p. 4176 - 4182
(2021/02/01)
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- An Additive-Free, Base-Catalyzed Protodesilylation of Organosilanes
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We report an additive-free, base-catalyzed C-, N-, O-, and S-Si bond cleavage of various organosilanes in mild conditions. The novel catalyst system exhibits high efficiency and good functional group compatibility, providing the corresponding products in good to excellent yields with low catalyst loadings. Overall, this transition-metal-free process may offer a convenient and general alternative to current employing excess bases, strong acids, or metal-catalyzed systems for the protodesilylation of organosilanes.
- Yao, Wubing,Li, Rongrong,Jiang, Huajiang,Han, Deman
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p. 2250 - 2255
(2018/02/23)
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- Palladium-catalyzed cyclization of alkynoic acids to form vinyl dioxanones bearing a quaternary allylic carbon
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A palladium-catalyzed intramolecular reaction of carboxylic acids and alkynes in a novel cyclization manner was developed. This unique cyclization efficiently provided a wide range of complex ring systems-vinyl dioxanones bearing a quaternary allylic carbon. Mechanistic studies suggest an allenyl carboxylate as an intermediate.
- Ogiwara, Yohei,Sato, Kazuya,Sakai, Norio
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supporting information
p. 5296 - 5299
(2017/11/06)
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- Ruthenium bipyridyl tethered porous organosilica: A versatile, durable and reusable heterogeneous photocatalyst
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A versatile heterogeneous photocatalysis protocol was developed by using ruthenium bipyridyl tethered porous organosilica (Ru-POS). The versatility of the Ru-POS catalyst in organo-photocatalysis was explored by (i) oxidative aromatization of Hantzsch ester, (ii) reductive dehalogenation of alkyl halides, and (iii) functional group interconversion (FGI) of alcohols to alkyl halides. This journal is
- Jana, Avijit,Mondal, John,Borah, Parijat,Mondal, Sujan,Bhaumik, Asim,Zhao, Yanli
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supporting information
p. 10746 - 10749
(2015/06/30)
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- MANUFACTURING OF STABILIZED PROPARGYL BROMIDE
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This invention provides a process for obtaining propargyl bromide in high yield from propargyl alcohol and phosphorus bromide, in the form of a stable composition with alkylbromide.
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Page/Page column 12; 13
(2014/04/04)
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- Iron-catalyzed synthesis of functionalized 2H-chromenes via intramolecular alkyne-carbonyl metathesis
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An iron-catalyzed intramolecular alkyne-aldehyde metathesis strategy of the alkynyl ether of salicylaldehyde derivatives has been developed which works under mild reaction conditions to produce the functionalized 2H-chromene derivatives. This protocol is compatible toward a wide range of functional groups, such as methoxy, fluoro, chloro, bromo, and phenyl groups. This method provides an atom-economical and environmentally friendly approach for the synthesis of a series of substituted 2H-chromenes.
- Bera, Krishnendu,Sarkar, Soumen,Biswas, Srijit,Maiti, Sukhendu,Jana, Umasish
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experimental part
p. 3539 - 3544
(2011/06/23)
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- Asymmetric synthesis of α-allenylglycines
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The coupling of the homocuprate of the bislactim ether of cyclo-(-L-Val-Gly-) (9) with primary propargyl halides produces the allenyl-substituted bislactim ethers 11 in a highly diastereoselective manner, whereas the alkylation of the lith-iated bislactim ether of cyclo-(-L-Val-Gly-) yields the proparg-yl-substituted bislactim ethers 12. Subsequent hydrolysis affords, after protection of the amino group, the methyl α- allenylglycinates 15, the α-allenylglycines 16, and the methyl α-propargylglycinates 17.
- Bucuroaia, Carmen,Groth, Ulrich,Huhn, Thomas,Klinge, Michael
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experimental part
p. 3605 - 3612
(2009/12/01)
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- Process for producing propargyl bromide
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This invention provides a process of producing propargyl bromide in the absence of abase. The process comprises: A) bringing together in a reaction zone under an inert atmosphere and in the absence of a base and in the presence of an inert diluent, a feed of phosphorus tribromide and a separate feed of propargyl alcohol thereby forming a reaction mixture; B) while mechanically agitating the mixture being formed in A), maintaining the temperature of the mixture in the range of about 0° C. to about 25° C. to form a product mixture, and then C) raising the temperature of the product mixture to a temperature in the range of about 40° C. to about 60° C. while stirring the product mixture for a ride period of at least about 2.5 hours. Such process can be conducted as a batch process, as a semi-batch process, or as a continuous process.
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- Rhodium(l)-catalyzed carbonyl allenylation versus propargylation via redox transmetalation across tetragonal tin(ll) oxide
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A reagent combination of β-SnO and catalytic [Rh(COD)Cl]2 in THF-H2O promotes the reaction of propargyl bromides and aldehydes and directs the regioselectivity toward the formation of either allenic alcohols or homopropargylic alcohols. This highly regioselective either/or transformation proceeds via a transmetalation from rhodium to tin, in which metallotropic rearrangement between a propargylmetal and allenylmetal is arrested.
- Banerjee, Moloy,Roy, Sujit
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p. 2137 - 2140
(2007/10/03)
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- Phase-Vanishing Methodology for Efficient Bromination, Alkylation, Epoxidation, and Oxidation Reactions of Organic Substrates
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(Matrix presented) In cases where both reactants in a phase-vanishing reaction are less dense than the fluorous phase, an alternative to the U-tube method is to employ a solvent with greater density than the fluorous phase, such as 1,2-dibromoethane. This modification has been successfully applied to the methylation of a phenol derivative with dimethyl sulfate and to the m-CPBA-induced epoxidation of alkenes, N-oxide formation from nitrogen-containing compounds, and S-oxide or sulfone formation from organic sulfides.
- Jana, Nirmal K.,Verkade, John G.
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p. 3787 - 3790
(2007/10/03)
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- Palladium(0) catalyzed regioselective carbonyl propargylation across tetragonal tin(II) oxide via redox transmetallation
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Facile homopropargylation of aldehydes by propargyl bromides over tetragonal tin(II)oxide and catalytic palladium(0) occurs which is proposed to involve the prior formation of dinuclear allenylpalladium followed by redox transmetallation to β-SnO.
- Banerjee, Moloy,Roy, Sujit
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p. 534 - 535
(2007/10/03)
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- [4,5]-fused-3,6-disubstituted-pyridazines with sulfur-containing substituents in position three for the treatment of neoplasia
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[4,5]-Fused-3,6 disubstituted-pydidazines of Formula I are useful for inducing or promoting apoptosis and for arresting uncontrolled neoplastic cell proliferation, and are specifically useful in the arresting and treatment of neoplasia: wherein Y1and Y2are independently selected from the group consisting of (CH2)n,—C(X)—NH—,—(CH2)n—C(X)—O—, and X is O or S; R1is selected from the group consisting of lower alkyl, lower alkenyl, lower alkynyl, and substituted or unsubstituted phenyl, pyridinyl, and the like; R2is selected from the group consisting of substituted or unsubstituted phenyl, benzyl, pyridinyl, and the like; “A” is a benzene ring fused with the pyridazine ring; and R3is independently selected in each instance form the group consisting of halogen, lower alkyl, and the like.
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- One-pot synthesis of aryl sulfones from alcohols
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A one-pot synthesis of aryl sulfones from primary alcohols is described. Alcohols were treated with N-bromosuccinimide and triphenylphosphine, followed by addition of sodium arenesulfinate with a catalytic amount of tetrabutylammonium iodide to afford the aryl sulfones in good to high yields.
- Murakami, Teiichi,Furusawa, Kiyotaka
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p. 479 - 482
(2007/10/03)
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- Triazole derivatives
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The present invention relates to triazole and imidazole derivatives of formula I and to their pharmaceutically acceptable acid addition salts. These compounds are NMDA receptor subtype blockers and are useful for the treatment of diseases related to the NMDA receptor.
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- Process for producing 1-substituted-hydantoins
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The subject is to provides a process for producing 1-substituted-hydantoins of Formula I: STR1 wherein R1 represents d hydrocarbon group which may be substituted and others, cheracterized by reacting N-sustituted-N-alkcycarbonylamnilo-acetonitrile of Formula II: STR2 wherein R2 represents an alkyl group and others, with an alkali metal hydroxides or the like and then treating with an acid.
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- Chloropyridylcarbonyl derivatives
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Novel chloropyridylcarbonyl derivatives of the formula STR1 in which Het is STR2 n is 1 or 2, R1 is hydrogen, optionally substituted C1-6 alkyl, optionally substituted C2-6 alkenyl, optionally substituted C3-6 alkynyl, optionally substituted phenyl or optionally substituted pyrimidinyl, and R2 and R3, independently of each other, are hydrogen or C1-4 alkyl, and acid addition salts and metal salt complexes thereof, are outstandingly active as microbicides.
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- Process for producing 1-substituted-hydantoins
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The subject is to provides a process for producing 1-substituted-hydantoins of Formula I: wherein R1represents a hydrocarbon group which may be substituted and others,characterized by reacting N-substituted-N-alkoxycarbonylamino-acetonitrile of Formula II: wherein R2represents an alkyl group and others,with an alkali metal hydroxides or the like and then treating with an acid.
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- METHOD OF TREATING DISORDERS OF THE DOPAMINERGIC SYSTEMS USING 2,5-DIAMINOTETRALINES
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The invention relates to novel 2,5-diaminotetralines of the formula: STR1 wherein R1, R2, R3 and R4 are defined herein, processes for preparing them and their use in pharmaceutical compositions. The novel 2, 5-diaminotetralines are useful in treating diseases caused by disorders of the dopaminergic systems.
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- Kinetics of the Reactions of Unsaturated Hydrocarbon Free Radicals (Vinyl, Propargyl, and Allyl) with Molecular Bromine
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The kinetics of the reactions of three unsaturated free radicals (vinyl, propargyl, and allyl) with molecular bromine have been studied by using a tubular reactor coupled to a photoionization mass spectrometer.The radicals were homogeneously generated by the pulsed photolysis of precursor molecules at 193 nm.The subsequent decays of the radical concentrations were monitored in time-resolved experiments as a function of Br2 concentration to obtain the rate constants of these Br-atom metathesis reactions.Rate constants were measured as a function of temperature to obtain Arrhenius parameters.The following rate constant expressions were obtained (units of the preexponential factor are cm3 molecule-1 s-1 and activation energies are kJ mol-1; the temperature range covered in each study is also indicated): C2H3 + Br2 , C3H3 + Br2 , and C3H5 +/- Br2 .The kinetics of R + Br2 reactions is reviewed, and the factors governing the reactivity of polyatomic free radicals in R + Br2 reactions are discussed.
- Timonen, R. S.,Seetula, J. A.,Gutman, D.
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p. 8217 - 8221
(2007/10/02)
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- Synthesis And Properties Of Certain n-Propargylphenothiazines And Their Cation Radicals
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N-Propargyl derivatives of 3-thiocyanato-, 2-chloro-, and 7-thiocyanato-2-chlorophenothiazines have been synthesized.Their capability for one-electron oxidation, forming cation radicals, has been investigated.EPR spectra of cation radicals obtained by different methods have been examined.
- Konovalova, E. P.,Tomilin, O. B.,Yuzhalkin, V. N.,Sanaeva, E. P.
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p. 1222 - 1225
(2007/10/02)
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- The thermal rearrangements of halocyclopropenes
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The gas phase thermal chemistry of several halocyclopropenes has been investigated. In each instance the cyclopropene was converted cleanly to an allene. The gas phase thermolysis of halocyclopropenes leads to allenes.
- Billups,Bachman, Robert E.
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p. 1825 - 1826
(2007/10/02)
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- Anti-tumour agents
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A quinazoline of the formula: STR1 wherein R1 is alkyl, cycloalkyl, alkenyl, alkynyl, alkoxy, alkylthio, aryl, aryloxy, arylalkyl, halogeno, hydroxy, mercapto, pyridylthio, pyrimidinylthio, or substituted alkyl or alkoxy; wherein R2 is hydrogen, alkyl, alkenyl, alkynyl, substituted alkyl or alkanoyl; wherein Ar is phenylene, naphthylene or heterocyclene which is unsubstituted or bears one or more substituents and wherein R3 is such that R3 --NH2 is an amino acid; or a pharmaceutically-acceptable salt or ester thereof. The compounds possess anti-tumour activity.
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- Heterogeneous mediated Alkylation of Ethyl Diethylphosphonoacetate. A "One Pot" Access to α-Alkylated Acrylic Esters
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Ethyl diethylphosphonoacetates are α-alkylated in high yield in a heterogeneous reaction with solid potassium carbonate as base.A "one pot" synthesis of α-alkylated acrylic esters is achiewed in a PO-actived olefination reaction aqueous media, when aqueous potassium carbonate and formaldehyde are added directly to the above reaction mixture.
- Kirschleger, Bernard,Queignec, Rene
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p. 926 - 928
(2007/10/02)
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- An easy access to homopropargylic ethers
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Chloromethyl ethers, obtained from alcohols, formaldehyde and HCl, react regioselectively, as shown previously in one case by L.Miginiac, with allenyl aluminium reagents derived from propargyl bromides and aluminium, to give homopropargyl ethers.No evidence for the presence of allenyl ethers was obtained in the cases described.This condensation is used to obtain a protected acetylenic synthon 1, required for the synthesis of an ecdysteroid analogue (1).
- Guedin-Vuong, Denis,Nakatani, Yoichi
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p. 245 - 252
(2007/10/02)
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- SYNTHESIS OF BROMOALLENE UNDER CONDITIONS OF PHASE-TRANSFER CATALYSIS
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A new method was developed for the production of bromoallene by the dehydrobromination of 1,2,3-tribromopropane under the conditions of phase-transfer catalysis.It was shown that the bromoallene is produced as a result of the isomerization of the initially formed propargyl bromide.During the dehydrohalogenation of 2-bromo-3-chloro-1-propene, bromoallene, i.e.; the product from rearrangement with participation of the bromine atom, is formed in addition to propargyl chloride and chloroallene.
- Kurginyan, K. A.,Arakelova, S. V.,Kalaidzhyan, A. E.
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p. 2127 - 2130
(2007/10/02)
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- SYNTHESE D'ALCOHOLS α-ALLENIQUES PAR REACTION D'ORGANOCHROMIQUES PROPARGYLIQUES SUR LES ALDEHYDES ET LES CETONES
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Propargylic bromides can be condensed with aldehydes and ketones in the presence of Hiyama's reagent (2CrCl3+LiAlH4 in THF) leading to α-allenic alcohols, to homopropargylic alcohols or to the mixture of both of them.The selectivity (or specificity) of this reaction depends on the substitution of the propargylic bromide, on the structure of the ketone, and on the presence of HMPT in the reaction mixture.In many cases, α- allenic alcohol has been specifically or very selectively obtained.The mechanism of the reaction and the influence of the various parameters are discussed.
- Place, Pierre,Verniere, Catherine,Gore, Jacques
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p. 1359 - 1368
(2007/10/02)
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- Carbon-Halogen Bonding Studies. Halogen Redistribution Reactions between Alkyl or Acetyl Halides and Tri-n-butyltin Halides
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The equilibrium positions have been determined for the halogen redistribution reactions of tri-n-butyltin halides with a variety of structurally different types of alkyl halides and with acetyl halides.These have been related through the reaction ΔGo values to carbon-halogen bond dissociation energy differences.It is suggested that the trends observed in the latter may provide evidence for the existence of a small steric bond weakening effect in the order C-I > C-Br > C-Cl bonds on going from methyl to primary, secondary, and tertiary alkyl halides.On the other hand, with the 2,3-? bond containing allyl, benzyl, and propargyl halides , α-haloacetones, and haloacetonitriles, there may be some type of electronic carbon-halogen bond strengthening effect which lies in order C-I > C-Br > C-Cl.Finally, for the acetyl halides, the data are in agreement with increases in bond strengths resulting from ? contributions being in the order C-Cl > C-Br > C-I.
- Friedrich, Edwin C.,Abma, Charles B.
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p. 1367 - 1371
(2007/10/02)
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- Novel N-allyl and N-propargyl benzmorphan derivatives
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N-Allyl-benzmorphan compounds having structures distinguished by having either a 4,5 or 6 carbon containing allyl group at the 2- or N-position or various ether derivatives of the 2'-hydroxy group. The compounds are prepared by alkylation of appropriate N-nor bases and have analgetic antagonist activity particularly pronounced in countering the effects of overdosing. Certain N-acyl-2'-hydroxy-5,9-dimethyl-6,7-benzmorphan intermediates are also disclosed.
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- Propargyl-substituted 2-phenylamino-2-imidazolines and salts thereof
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Compounds of the formula STR1 wherein R1, R2 and R3, which may be identical to or different from each other, are each hydrogen, fluorine, chlorine, bromine, methyl, ethyl, methoxy or trifluoromethyl, and R4 and R5 are each hydrogen or propargyl, but other than both hydrogen or both propargyl at the same time, And non-toxic, pharmacologically acceptable acid addition salts thereof; the compounds as well as the salts are useful as analgesics and hypotensives.
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- Novel indolobenzazepine derivatives, useful as tranquilizers
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Certain novel 1,2,3,4,8,9-hexahydro-3-(substituted)pyrido[4',3':2,3]indolo[1,7-ab][1]-benzazepines are useful as minor tranquilizers (anxiolytics) and/or major tranquilizers (antipsychotics). The minor tranquilizers are effective at non-ataxic doses, and are not likely to cause addiction when abused. A representative compound in this class is 3-(cyclopropylmethyl)-1,2,3,4,8,9-hexahydropyrido[4',3':2,3]indolo[1,7-ab][1]benzazepine.
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