20615-64-9Relevant articles and documents
Low-temperature heat capacity and standard molar enthalpy of formation of 9-fluorenemethanol (C14H12O)
Di, You-Ying,Tan, Zhi-Cheng,Sun, Xiao-Hong,Wang, Mei-Han,Xu, Fen,Liu, Yuan-Fa,Sun, Li-Xian,Zhang, Hong-Tao
, p. 79 - 86 (2004)
Low-temperature heat capacities of the 9-fluorenemethanol (C 14H12O) have been precisely measured with a small sample automatic adiabatic calorimeter over the temperature range between T = 78 K and T = 390 K. The solid-liquid phase transition of the compound has been observed to be Tfus = (376.567 ± 0.012) K from the heat-capacity measurements. The molar enthalpy and entropy of the melting of the substance were determined to be ΔfusHm = (26.273 ± 0.013) kJ · mol-1 and ΔfusSm = (69.770 ± 0.035) J · K-1·mol-1. The experimental values of molar heat capacities in solid and liquid regions have been fitted to two polynomial equations by the least squares method. The constant-volume energy and standard molar enthalpy of combustion of the compound have been determined, ΔcU(C14H 12O, s) = -(7125.56 ± 4.62) kJ·mol-1 and ΔcHm°(C14H12 O, s) = -(7131.76 ± 4.62) kJ · mol-1 by means of a homemade precision oxygen-bomb combustion calorimeter at T = (298.15 ± 0.001) K. The standard molar enthalpy of formation of the compound has been derived, Δf Hm°(C14H 12 O, s) = -(92.36 ± 0.97) kJ · mol-1, from the standard molar enthalpy of combustion of the compound in combination with other auxiliary thermodynamic quantities through a Hess thermochemical cycle.
Aldehyde and Enol Contents of 9-Formylfluorene
Harcourt, Myles P.,O'Ferrall, Rory A. More
, p. 822 - 823 (1987)
In aqueous solution at 25 deg C 9-formylfluorene is present mainly as its enol (72percent, KE = 17) and hydrate (24percent, Kh = 5.6); the unstable aldehyde (4percent) may be generated for kinetic and equilibrium measurement by reaction of its ethanethiol hemithioacetal with iodine.
Preparation method of 9-fluorenecarboxaldehyde
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Paragraph 0019-0022, (2021/05/01)
The invention relates to the field of fine chemical intermediate synthesis, in particular to a preparation method of a chemical intermediate 9-fluorene formaldehyde, which comprises the following steps: adding industrial fluorene, metal alkoxide and ethyl formate into a solvent, and reacting at 30-80 DEG C for 0.5-10 hours to obtain 9-fluorene formaldehyde; and after the reaction is finished, cooling, carrying out acid quenching reaction, extracting, regulating the pH value to be less than 3 by using a water phase, separating out a solid, and recrystallizing to obtain a target product. The preparation method of 9-fluorene formaldehyde provided by the invention has the characteristics of safety, environmental protection and easy operation, the conversion rate of fluorene is high, the product purity is good, and a new way is provided for improving the utilization rate of industrial fluorene.
Method for high-selectivity synthesis of 9-fluorenylcarbinol
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Paragraph 0025-0026; 0032-0033; 0039-0040; 0046-0047; 0053, (2021/06/06)
The invention discloses a method for high-selectivity synthesis of 9-fluorenylcarbinol. The method comprises the following steps: heating and dissolving fluorene in a DMSO solvent system at 50-55 DEG C in the presence of a sodium ethoxide ethanol solution alkali catalyst, adding an acylation reagent ethyl formate, carrying out acylation reaction at the same temperature to prepare 9-fluorenylformaldehyde, adding a soluble metal inorganic salt auxiliary agent, then using NaBH4 for a reduction reaction, adjusting the pH value of reaction liquid to be neutral, and separating out 9-fluorene methanol solid sediment. According to the method disclosed by the invention, fluorene is completely converted by utilizing a section of temperature, the 9-fluorene methanol can be obtained through high-selectivity reduction without solvent conversion by adding the soluble metal inorganic salt auxiliary agent, and the yield of the 9-fluorene methanol is improved on the premise of shortening the reaction time.
Strongly coupled Mn3O4-porous organic polymer hybrid: A robust, durable and potential nanocatalyst for alcohol oxidation reactions
Dhanalaxmi, Karnekanti,Singuru, Ramana,Kundu, Sudipta K.,Reddy, Benjaram Mahipal,Bhaumik, Asim,Mondal, John
, p. 36728 - 36735 (2016/05/24)
Herein we describe a novel strategy for noble-metal-free Mn3O4@POP (porous organic polymer) hybrid synthesis by encapsulation of Mn3O4-NP in the interior cavity of a porous organic polymer which exhibited enhanced catalytic activity and stability for oxidation of diverse activated and nonactivated alcohols relative to the conventional catalysts to demonstrate the benefits of such a nanoarchitecture in heterogeneous nanocatalysis. The use of a non precious catalyst, tremendous recyclability (upto 15 catalytic runs) and exceptional stability make our system innovative in nature, addressing all the profound challenges in the noble-metal-free heterogeneous catalysts development community.
Chemoselective deprotection and deprotection with concomitant reduction of 1,3-dioxolanes, acetals and ketals using nickel boride
Khurana, Jitender M.,Dawra, Kiran,Sharma, Purnima
, p. 12048 - 12051 (2015/02/19)
An efficient and mild methodology for the reductive deprotection of 1,3-dioxolanes, acetals and ketals to the corresponding aldehydes/ketones and also deprotection with concomitant reduction to the corresponding alcohols has been achieved in quantitative yields using nickel boride generated in situ from nickel chloride and sodium borohydride in methanol. The reactions are chemoselective as halo, alkoxy and methylenedioxy groups are unaffected.
Cellulose supported manganese dioxide nanosheet catalyzed aerobic oxidation of organic compounds
Shaabani, Ahmad,Hezarkhani, Zeinab,Shaabani, Shabnam
, p. 64419 - 64428 (2015/04/27)
Cellulose supported manganese dioxide nanosheets, as a heterogeneous bio-supported and green catalyst, were synthesized by soaking porous cellulose in a potassium permanganate solution. The prepared catalyst was used effectively for the oxidation of various types of alkyl arenes, alcohols and sulfides to their corresponding carbonyl and sulfoxide compounds, respectively in high yields using air as the oxidant at ambient pressure. The catalyst can be recycled and reused in five runs without any significant loss of efficiency. The mild reaction conditions for the oxidation of alcohols and sulfides, high yields, recyclability of the catalyst, and very easy workup procedure are other advantages of this catalyst.
Oxidative cleavage of α-aryl aldehydes using iodosylbenzene
Havare, Nizam,Plattner, Dietmar A.
supporting information, p. 5078 - 5081,4 (2020/09/15)
We found that α-aryl aldehydes can be cleaved to chain-shortened carbonyl compounds and formaldehyde by various iodosylbenzene complexes. A mechanistic scheme is presented that accounts for the loss of one carbon atom. Formaldehyde is further oxidized to CO and CO2 under the reaction conditions.
Synthesis and structure-activity relationships of A novel class of dithiocarbamic acid esters as anticancer agent
Hou, Xueling,Ge, Zemei,Wang, Tingmin,Guo, Wei,Wu, Jun,Cui, Jingrong,Lai, Chingsan,Li, Runtao
experimental part, p. 320 - 332 (2011/11/05)
Based on a novel lead compound 4-methylpiperazine-1-carbodithioic acid 3-cyano-3,3-diphenylpropyl ester 1, the systematic structural modification was carried out. All the synthesized compounds were evaluated for their in-vitro anticancer activities on four to six different cell lines at three different concentrations. Most of the tested compounds could selectively inhibit the growth of HL-60 and Bel-7402 cell lines at a medium concentration. Four compounds (3f, 3g, 3n, and 5) were selected for the IC50 test, and the results revealed that three compounds (3g, 3n, and 5) showed almost the same or a slightly weaker activity than compound 1 against HL-60, and three compounds (3f, 3g, and 3n) showed >2-fold higher potency than compound 1 against Bel-7402. The in-vivo efficacy of 3n · HCl was evaluated with transplanted hepatocyte carcinoma 22 as an in-vivo test model. It was found that 3n · HCl could inhibit significantly the growth of tumor, and that this effect was dose-dependent. Meanwhile, the compound 3n · HCl showed low toxicity compared with compound 1 · HCl as evidenced by the little body-weight loss. These results confirmed that compound 3n · HCl is more potent than the lead compound 1 · HCl. Preliminary structure-activity relationships indicated that: a) Both nitrile group and the cyclic amine containing at least two nitrogens were indispensable moieties to keep the activity; b) substitution of the piperazine ring is unfavorable for the improvement of activity; c) the suitable linker joining the piperazinyl dithiocarboxyl and diphenylacetonitril group should be ethylene; d) a non-coplanar arrangement of the two benzene rings appears to be essential for activity. Based on a novel lead compound 4-methyl-piperazine-1-carbodithioic acid 3-cyano-3,3-diphenyl-propyl ester 1, the systematic structural modification was carried out. Compounds 3g and 3n were found to show more potent biological activities than lead compound 1. Some useful SARs were revealed Copyright
Rate and equilibrium constants for formation and hydrolysis of 9-formylfluorene oxime: Diffusion-controlled trapping of a protonated aldehyde by hydroxylamine
More O'Ferrall,O'Brien,Murphy
, p. 1594 - 1612 (2007/10/03)
Equilibrium constants Kadd = 440 and Kox = 3.0 × 108 for formation of a carbinolamine adduct and oxime, respectively from 9-formylfluorene and hydroxylamine, and pKa = -1.62 for protonation of the oxime, have been evaluated at 25°C in aqueous solution, based on measurements in hydroxylamine buffers, acetic acid buffers, and dilute HCI. Rate constants for hydrolysis of the oxime have been measured in the acidity range pH 4-12 M HClO4. At the highest acidities, a reaction pathway via protonated carbinolamine has been identified: evidence is presented that the reverse of this reaction involves rate-determihing attack of hydroxylamine upon protonated 9-formylfluorene. By assuming that the attack of hydroxylanfine is diffusion-controlled, with rate constant 3 × 109 M-1 s-1, a pKa for O-protonation of the aldehyde (-4.5) is derived. Taking account of the equilibrium constant for enolization of 9-formylfluorene (KE = 16.6), a pKa for C-protonation of the enol tautomer (-5.7) may also be obtained. Comparison of this pKa with that of the enol of acetophenone shows that the enol of 9-formylfluorene is less basic by a factor of 1010. By combining pKas for protonanon of the aldehyde and oxime with measured or estimated equilibrium constants for addition of water, hydroxide ion, and hydroxylamine to 9-formylfluorene, it is also possible to obtain values of pKR = -5.3, 4.1, and 12.25 for the protonated 9-formylfluorene, protonated oxime, and 9-formylfluorene, respectively. The usefulness of pKR in providing a general measure of equilibrium constants for electrophile-nucleophile combination reactions is discussed.
