ChemInform Abstract: An Optimized Procedure to Prepare 3‐Acylindoles: Triethyl Orthoacetate and Trimethyl Orthobenzoate as Effective Acylation Reagents.

Pfeuffer, L.; Sody, E.; Pindur, U.

doi:10.1002/chin.198732187

Cited by 3 publications

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“…Materials. The indolylfulgide 1 was prepared, starting from 1,2-dimethylindole, following literature procedures. − Preparation of the phosphorylated poly(VBC- co -MMA) used for the formation of the polymer film was described previously, consisting of a mole ratio of diethyl vinylbenzylphosphonate to MMA of 1:3 in the polymer . Solvents were purchased as HPLC or spectrophotometric grade from Sigma-Aldrich and used as received.…”

Section: Methodsmentioning

confidence: 99%

Two-Photon Photochromism of an Organic Material for Holographic Recording

et al. 2002

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We report the two-photon-induced photoisomerization of 3-[1-(1,2-dimethyl-1H-indol-3-yl)-ethylidene]-4-isopropylidene-dihydrofuran-2,5-dione (1), a photochromic compound with λ max ) 385 nm, using 775-nm femtosecond pulsed laser irradiation. The resulting photoisomer had λ max ) 582 nm. The kinetic rate constant for the two-photon-induced electrocyclic isomerization reaction was measured at two different intensities (two different powers), showing a quadratic dependence with respect to the pump intensity. Results of pump-probe solution phase experiments and guest/host polymer thin film interferometric imaging studies are reported. A two-photon absorption molecular cross section σ2 ) 10.3 × 10 -48 cm 4 ‚s/photon was measured using Z-scan, further supporting a two-photon-induced isomerization process. Two-photon-induced interferometric recording in a fulgide-containing polymer film was demonstrated.

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Section: Methodsmentioning

confidence: 99%

Two-Photon Photochromism of an Organic Material for Holographic Recording

et al. 2002

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“…treatment of indole with EtMgI in dry ether followed by reaction with acetyl chloride producing 3-acetylindole) (2) acylation of N-protected indoles [15] and (3) the VilsmeierHaack reaction [11] (on simple and substituted indoles) . There are also other methods based on acyl cation equivalents, such as nitrilium salts [16] and on dialkyl carbenium ions [17,18]. Another method, using N-(Rhaloacyl)pyridinium salts, gives predominantly 3-acylindoles under controlled conditions, but it seems to be restricted to some very reactive R-haloacyl halides [19].…”

Section: Introductionmentioning

confidence: 97%

Novel and Simple Methodology for the Synthesis of 3-Acetylindoles and their N-Alkyl Derivatives Using TBAB as Phase Transfer Catalyst

Venkatanarayana

Dubey

2011

LOC

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Using 5% aq. NaOH, a simple method for the transformation of 3-cyanoacetylindoles 2(a-e) into 3-acetylindoles 3 (a-e), in good yields, is reported. Tetrabutylammoniumbromide (TBAB) is found to be an efficient phase transfer catalyst for the synthesis of N-alkyl derivatives 5(a-t) of 3-acetylindoles 3(a-e) giving products in excellent yields. 2 (a-e) were themselves obtained from simple indoles 1 (a-e) by reaction with cyano acetic acid in the presence of propionic anhydride at 100 ˚C for 5-10 min. Partial hydrolysis of 2 (a-e) under hot acidic conditions yielded the corresponding carboxamides -(3-indolecarboxoyl)acetamides 4(a-e). Which could be readily transformed into the respective 3(a-e) by refluxing with 5% aq. NaOH for 2-2.5 h.

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“…Three major synthetic methods have been employed to prepare this class of compounds using indole as the starting material: (1) acylation of indole Grignard reagents, − (2) acylation of N-protected indoles, and (3) the Vilsmeier−Haack reaction and dialkyl carbenium ions. , Another method, using N -(α-haloacyl)pyridinium salts, gives predominantly 3-acylindoles under controlled conditions, but it seems to be restricted to some very reactive α-haloacyl halides . Each of these methodologies has merits and shortcomings that limit their scope and yield.…”

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confidence: 99%

Acylation of Indole under Friedel−Crafts ConditionsAn Improved Method To Obtain 3-Acylindoles Regioselectively

et al. 2001

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The reaction of unsubstituted indole with different acylating agents such as acid chlorides, anhydrides, nitriles, and amino acid derivatives in the presence of Lewis acid is reported.The synthesis of 3-acylindoles has been the subject of considerable interest not only because they are used as synthetic intermediates in alkaloid synthesis but also because they have biological activities. 1 Three major synthetic methods have been employed to prepare this class of compounds using indole as the starting material: (1) acylation of indole Grignard reagents, [2][3][4] (2) acylation of N-protected indoles, 5 and (3) the Vilsmeier-Haack reaction. 2 There are also other methods based on acyl cation equivalents such as nitrilium salts 6 and dialkyl carbenium ions. 7,8 Another method, using N-(R-haloacyl)pyridinium salts, gives predominantly 3-acylindoles under controlled conditions, but it seems to be restricted to some very reactive R-haloacyl halides. 9 Each of these methodologies has merits and shortcomings that limit their scope and yield.

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ChemInform Abstract: An Optimized Procedure to Prepare 3‐Acylindoles: Triethyl Orthoacetate and Trimethyl Orthobenzoate as Effective Acylation Reagents.

Abstract: 187ChemInform Abstract The indoles (I) react regioselectively with the orthoesters (II) to produce the 3-acetyl or 2-benzoylindoles (III). (1H-NMR-data).

Cited by 3 publications

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Two-Photon Photochromism of an Organic Material for Holographic Recording

Two-Photon Photochromism of an Organic Material for Holographic Recording

Novel and Simple Methodology for the Synthesis of 3-Acetylindoles and their N-Alkyl Derivatives Using TBAB as Phase Transfer Catalyst

Acylation of Indole under Friedel−Crafts ConditionsAn Improved Method To Obtain 3-Acylindoles Regioselectively

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