18664-32-9Relevant academic research and scientific papers
Kinetics and mechanism of oxidation of aliphatic secondary alcohols by benzimidazolium fluorochromate in dimethyl sulphoxide solvent
Arora, Bhawana,Ojha, Jitendra,Mishra, Pallavi
, p. 626 - 633 (2021/07/10)
Oxidation of secondary alcohols is an important part of synthetic organic chemistry. Various studies are carried out at different reaction conditions to determine the best mechanistic pathways. In our study, oxidation of different secondary alcohols was done by using Benzimidazolium Fluorochromate in dimethyl sulphoxide, which is a non-aqueous solvent. Oxidation resulted in the formation of ketonic compounds. The reaction showed first order kinetics both in BIFC and in the alcohols. Hydrogen ions were used to catalyze the reaction. We selected four different temperatures to carry out our study. The correlation within the activation parameters like enthalpies and entropies was in accordance with the Exner's criterion. The deuterated benzhydrol (PhCDOHPh) oxidation exhibited an important primary kinetic isotopic effect (kH/kD = 5.76) at 298 K. The solvent effect was studied using the multiparametric equations of Taft and Swain. There was no effect of addition of acrylonitrile on the oxidation rate. The mechanism involved sigmatropic rearrangement with the transfer of hydrogen ion taking place from alcohol to the oxidant via a cyclic chromate ester formation.
Kinetics and mechanism of oxidation of aliphatic secondary alcohols by benzyltrimethylammonium chlorobromate
Sharma, Pradeep K.
, p. 2702 - 2706 (2014/06/09)
Oxidation of several secondary alcohols by benzyltrimethylammonium chlorobromate (BTMACB) in aqueous acetic acid leads to the formation of corresponding ketones. The reaction is first order with respect to BTMACB and the alcohols. The reaction failed to induce the polymerization of acrylonitrile. There is no effect of tetrabutylammonium chloride on the reaction rate. The proposed reactive oxidizing species is chlorobromate ion. The oxidation of benzhydrol-α-d (PhCDOHPh) exhibited a substantial primary kinetic isotope effect (kH/kD = 5.61 at 298 K). The effect of solvent composition indicated that the rate increases with an increase in the polarity of the solvent. The reaction is susceptible to both the polar and steric effects of the substituents. A mechanism involving transfer of a hydride ion in the ratedetermining step has been proposed.
Synthesis and biological evaluation of rebeccamycin analogues modified at the imide moiety
Animati, Fabio,Berettoni, Marco,Bigioni, Mario,Binaschi, Monica,Cipollone, Amalia,Irrissuto, Clelia,Nardelli, Federica,Olivieri, Lauso
scheme or table, p. 5013 - 5017 (2012/09/07)
Glycosylated indolocarbazoles related to the antibiotic rebeccamycin represent an important class of antitumour drugs. In the course of our structure-activity relationship studies, new rebeccamycin analogues modified at the imide moiety were synthesised. The antiproliferative activity of the compounds was evaluated on three human cancer cell lines, A2780 (ovarian cancer), H460 (lung cancer), and GLC4 (small-cell lung cancer). The in vitro cytotoxicity of compounds 2 and 4, characterised respectively by a 1,3-dioxolan and (1,3-dioxolan-4-yl)methylene groups linked to the imide moiety, was higher than the reference compound, edotecarin. The effect of compound 2 in inducing tumour regression in the A2780 xenograft model was also investigated.
Compound having histone deacetylase-inhibiting activity, and pharmaceutical composition comprising the compound as an active ingredient
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, (2012/04/23)
A novel compound having histone deacetylase-inhibiting activity which is a cyclic tetrapeptide derivative represented by the general formula (1) given below and a pharmaceutical composition comprising such compound as an active ingredient. (In the formula, the cyclic tetrapeptide moiety has a known structure; R1 and R2 each independently represents an alkylene group containing 1 to 6 carbon atoms, which may be branched; X represents a group or bond selected from among —CO—, —O—, —S— or —SO—; Y represents a hydrogen or halogen atom, a phenyl group (including a substituted form), a pyridyl group (including a substituted form), an alkyl group (including a halogen-substituted form; hereinafter the same shall apply) containing 1 to 6 carbon atoms, an alkyloxy group containing 1 to 6 carbon atoms, an alkylcarbonyl group containing 1 to 6 carbon atoms, an alkyloxycarbonyl group containing 1 to 6 carbon atoms, an alkylthio group containing 1 to 6 carbon atoms, an alkylthiocarbonyl group containing 1 to 6 carbon atoms or a mono- or dialkylamino group containing 1 to 6 carbon atoms; when Y is a phenyl group (including a substituted form) or a pyridyl group (including a substituted form), it may form a further cyclic structure bound to R2.)
Kinetics and mechanism of oxidation of secondary alcohols by benzyltriethylammonium chlorochromate
Kaur, Ravdeep,Soni, Neelam,Sharma, Vinita
, p. 2441 - 2445 (2007/10/03)
Oxidation of several aliphatic secondary alcohols by benzyltriethylammonium chlorochromate in dimethylsulfoxide leads to the formation of corresponding ketones. The reaction is first order each in benzyltriethylammonium chlorochromate and the alcohols. The reaction is catalysed by hydrogen ions. Hydrogen-ion dependence has the form: kobs = a + b [H+]. The oxidation of benzhydrol-α-d exhibits a substantial primary kinetic isotope effect (kH/kD = 6.12 at 288 K). Oxidation of 2-propanol has been studied in nineteen different organic solvents. The solvent effect has been analysed using Taft's and Swain's multiparametric equations. The reaction has been subjected to both polar and steric effects of the substituents. A mechanism involving transfer of hydride ion from alcohol to the oxidant via a chromate ester is also proposed.
Synthesis of 2,5-dihydrofurans via alkylidene carbene insertion reactions
Walker, Louise F.,Bourghida, Ahmed,Connolly, Stephen,Wills, Martin
, p. 965 - 981 (2007/10/03)
The insertion reaction of alkylidene carbenes is demonstrated to be an effective method for the synthesis of 2,5-dihydrofuran ring systems. The best results have been obtained on substrates containing electron-withdrawing substituents, which appear less prone to the competing rearrangement reaction. This insight has led to the development of a new method for the synthesis of the core structure of the squalestatin-zaragozic acid natural products.
Kinetics and mechanism of the oxidation of secondary alcohols by tetrabutylammonium tribromide
Gosain, Jaya,Sharma, Pradeep K.
, p. 815 - 818 (2007/10/03)
Oxidation of several secondary alcohols by tetrabutylammonium tribromide (TBATB) in aqueous acetic acid leads to the formation of corresponding ketones. The reaction is first order with respect to TBATB and the alcohols. The reaction failed to induce polymerization of acrylonitrile. There is no effect of tetrabutylammonium chloride on the reaction rate. The proposed reactive oxidizing species is tribromide ion. The oxidation of benzhydrol-α-d (PhCDOHPh) exhibited a substantial primary kinetic isotope effect (k H/kd = 5.15 at 298 K). The effect of solvent composition indicates that the rate increases with an increase in polarity of the solvent. The reaction is susceptible to both polar and steric effects of the substituents. A mechanism involving transfer of a hydride ion in the rate-determining step has been proposed.
Synthesis of 2,5-dihydrofurans via alkylidene carbene insertion reactions
Walker, Louise F.,Connolly, Stephen,Wills, Martin
, p. 5273 - 5276 (2007/10/03)
The insertion of vinylidene carbenes into C-H bonds is an efficient method for the synthesis of 2,5-dihydrofurans. The methodology provides a convenient entry to the core structure of squalestatin/zaragozic acid natural products.
Synthesis and selective coronary vasodilatory activity of 3,4-dihydro- 2,2-bis(methoxymethyl)-2H-1-benzopyran-3-ol derivatives: Novel potassium channel openers
Cho, Hidetsura,Katoh, Susumu,Sayama, Shinsuke,Murakami, Kengo,Nakanishi, Hiroyuki,Kajimoto, Yasuyuki,Ueno, Hiroshi,Kawasaki, Hisashi,Aisaka, Kazuo,Uchida, Itsuo
, p. 3797 - 3805 (2007/10/03)
A variety of compounds having a benzopyran such as levcromakalim generally exhibit potent antihypertensive activity. During extensive investigations aimed toward identifying K+ channel openers having selective coronary vasodilation without pote
KINETICS AND MECHANISM OF BASE-CATALYSED ALDOLIZATION OF 1,3-DIMETHOXY-2-PROPANONE
Fedoronko, Michal,Petrusova, Maria,Kovacik, Vladimir
, p. 2252 - 2259 (2007/10/02)
1,3-Dimethoxy-2-propanone (HA) in an aqueous alkaline solution undergoes specifically base-catalysed aldolization with the formation of a dimer, 4-hydroxy-1,3,5-trimethoxy-4-methoxymethyl-2-pentanone (H2A2).The reaction is reversible and involves the formation of decompostion of an intermediate anion, HA2-, as the rate determining step.The formation of a carbanion ion, A-, of the starting compound and of the HA2- anion are rapid, preceding, and generally base-catalysed reaction steps.The activation and thermodynamic parameters of the reversible reaction were determined form the dependences of the rate and the equilibrium constants on the temperature.
