41340-36-7Relevant articles and documents
Preparation method of 7-ethyl chrotol
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Paragraph 0057-0072, (2021/11/21)
The invention belongs to the technical field of drug synthesis, and particularly relates to a preparation method of 7-ethyl chromone, which comprises the following steps: reacting 7-ethyl indole serving as a raw material with ethylene carbonate under the action of alkali to synthesize 7-ethyl chromone; the hydroxyethyl ethylene carbonate reagent product introduced in the method is carbon dioxide, the method is clean and environmentally friendly, post-treatment is convenient, dangerous chemical reagents are not used, the reaction is milder, economical and environmentally friendly, the yield is high, and the method is suitable for industrial production.
A microwave promoted 7 - ethyl tryptophol continuous synthetic method (by machine translation)
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Paragraph 0026-0046, (2018/01/14)
The invention provides a microwave promoted 7 - ethyl tryptophol continuous synthetic method, the design of a microwave heating tube type continuous flow apparatus, by microwave heating tubular continuous flow reaction technology, the 7 - ethyl tryptophol continuous synthesis of reaction; compared with the existing method, the reaction of the invention speed, less side reaction, the mass transfer efficiency is high, the reaction selectivity is high, high purity, high yield and after treatment is convenient. (by machine translation)
On the Fischer indole synthesis of 7-ethyltryptophol - Mechanistic and process intensification studies under continuous flow conditions
Gutmann, Bernhard,Gottsponer, Michael,Elsner, Petteri,Cantillo, David,Roberge, Dominique M.,Kappe, C. Oliver
, p. 294 - 302 (2013/05/08)
7-Ethyltryptophol, a key intermediate in the synthesis of the anti-inflammatory agent etodolac, was produced by Fischer indole synthesis of 2-ethylphenylhydrazine and 2,3-dihydrofuran under continuous flow conditions. The reaction generates several undesired byproducts and therefore product yields could not be improved above 40-50%. The mechanism of this transformation was studied in detail and the structure of the byproducts carefully elucidated. Despite the only moderate product yield, the synthesis of 7-ethyltryptophol by this protocol remains interesting compared to alternative methods and starts from inexpensive reagents. The developed process is executed in an environmentally benign solvent (methanol) and, importantly, the majority of byproducts can be removed from the 7-ethyltryptophol product by a straightforward extraction process.
An improved and scalable process for the synthesis of a key intermediate for Etodolac, a non-steroidal anti-inflammatory drug
Chandra Sekharayya,Venkata Narayana,Nigam, Satish,Madhusudhan
, p. 1763 - 1766 (2013/03/13)
An improved and scalable method is developed for the synthesis of 7-ethyltryptophol, a key intermediate for Etodolac, a non-steroidal anti-inflammatory drug (NSAID) starting from commercially available 2-ethylphenyl hydrazine and dihydrofuran with H2SO4 as a catalyst in N,N-dimethylacetamide (DMAc)-H2O (1:1) as a solvent in 69% yield. The method is easy, inexpensive and reproducible and the process is clean, high yielding and operationally simple.
A continuous kilogram-scale process for the manufacture of 7-ethyltryptophol
Lv, Yanwen,Yu, Zhiqun,Su, Weike
, p. 471 - 475 (2013/01/10)
An expeditious and multikilogram-scale process for the synthesis of 7-ethyltryptophol via a continuous flow reactor from 2-ethylphenylhydrazine and 4-hydroxybutyraldehyde in higher and high yield was described. The main steps in this synthesis involved not only the generation of the hydrazone intermediate in situ but also the catalysis of the subsequent [3 + 3] sigmatropic rearrangement in the tandem loop reactor. Decomposition of the intermediate hydrazone was found to be a key factor resulting in low yield.
Process for preparing highly pure and free-flowing solid of 7-ethyltryptophol
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Page/Page column 2, (2008/06/13)
An industrial purification process for preparing a highly pure and free flowing solid of 7-ethyltryptophol. Crude 7-ethyltryptophol, prepared by, known procedures is dissolved in an organic solvent and washed with aqueous acid solution to form an aqueous phase and an organic phase. After at least partially removing the solvent from the organic phase, it is triturated with an alkane solvent under cooling to solidify the residue. A highly pure and free-flowing solid of 7-ethyltryptophol is recovered therefrom.
SUBSTITUTED INDOLE DERIVATIVES
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Page/Page column 81, (2008/06/13)
Provided herein are indole derivatives, pharmaceutical compositions containing them, methods for their use, and methods for preparing these compounds.
A novel substitution reaction of tetrahydropyrano[3,4-b]indole derivative - Chain extension and structural correlation study
Chou, Shan-Yen
, p. 1095 - 1110 (2007/10/03)
An unusual cyanation with rearrangement of a 1-chloromethyl-tetrahydropyrano[3,4-b]indole-1-acetic acid ester derivative is reported. The resulting C-1 chain extension product is identified by correlation studies and spectral method.
A versatile synthetic methodology for the synthesis of tryptophols
Garden, Simon J,Da Silva, Rosangela B,Pinto, Angelo C
, p. 8399 - 8412 (2007/10/03)
Tryptophols have been obtained in high yields by the reduction of 3-substituted-dioxindoles (obtained by the aldol condensation reaction of ketones with isatins or by a modified Knovenagel malonate condensation) using a borane tetrahydrofuran complex. The reported methodology offers distinct advantages over existing methods for the synthesis of these compounds, including consistently greater yields, diastereoselective syntheses and the possibility for the synthesis of a wide range of structurally different tryptophols. The reduction reaction was found to proceed via an intermediate 1,3-diol-oxindole, which was obtained diastereoselectively and, which was subsequently reduced to the corresponding tryptophol.
Kinetics and mechanisms of etodolac degradation in aqueous solution
Lee,Padula,Lee
, p. 81 - 86 (2007/10/02)
The extent and mechanisms of etodolac (1; 1,8-diethyl-1,3,4,9-tetrahydropyrano[3,4-b]-indole-1-acetic acid) decomposition, as a function of pH and temperature, were investigated. Three main degradation products derived from 1 are identified as 7-ethyl-2-(1-methylenepropyl)-1H-indole-3-ethanol (2), the decarboxylated product of etodolac (3), and 7-ethyltryptophol (4). The main pathway for the degradation of 1 is followed by consecutive first-order kinetics: 1 → 2 ? 3 → 4. No appreciable buffer effect on the degradation of 1 is observed for any of the buffer species in the study. The rate-pH profile exhibits a specific acid catalysis at acidic (k(H)) and neutral (k'(H)) pH regions, and an inflection point at pH 4.65 corresponding to the pK(a) value. From Arrhenius plots, the activation energies (E(a)) for k(H) and k'(H) were found to be 26 and 24 kcal/mol, respectively. The small positive entropy of activation (ΔS(≠)) indicates that a unimolecular decomposition mechanism is favored for the decomposition reaction of 1.
