13671-74-4Relevant academic research and scientific papers
A Novel and Chemoselective Process of N -Alkylation of Aromatic Nitrogen Compounds Using Quaternary Ammonium Salts as Starting Material
González-González, Carlos A.,Vega, Juan Javier Mejía,Monroy, Ricardo García,González-Calderón, Davir,Corona-Becerril, David,Fuentes-Benítes, Aydeé,Mascarúa, Joaquín Tamariz,González-Romero, Carlos
, (2018/02/28)
The process of N-alkylation of several pyrroles, indoles, and derivative heterocycles is herein described, using quaternary ammonium salts as the source of an alkylating agent. These reactions were carried out on several heterocyclic rings with triethylbenzylammonium chloride or tetradecyltrimethylammonium bromide and an NaOH solution at 50%, leading to a chemoselective N-alkylated product and an average yield of 73%. This is an alternative process to the traditional benzylation and methylation of N-heterocycles with direct handling of alkyl halides.
Formation of N-substituted 4- and 7-oxo-4,5,6,7-tetrahydroindoles revisited: A mechanistic interpretation and conversion into 4- and 7-oxoindoles
Montalban, Antonio Garrido,Baum, Sven M.,Cowell, Justin,McKillop, Alexander
experimental part, p. 4276 - 4279 (2012/09/25)
An efficient method for the preparation of 4-oxo-4,5,6,7-tetrahydroindoles was successfully applied to the synthesis of N-substituted 7-oxo-4,5,6,7- tetrahydroindoles for the first time. Both isomers where converted into their corresponding 4- and 7-oxoindoles in good yields utilizing a novel aromatization protocol. Based on the impurity profile obtained, however, different mechanisms for the formation of the 4- and 7-oxo-4,5,6,7-tetrahydroindole derivatives are discussed. In addition, the reaction sequences appear to be stereospecific allowing for the direct introduction of a chiral center α to the nitrogen and preparation of enantiomerically enriched products.
Microwave-assisted synthesis of tetrahydroindoles
Piras, Leonarda,Ghiron, Chiara,Minetto, Giacomo,Taddei, Maurizio
, p. 459 - 462 (2008/09/17)
An efficient synthesis of tetrahydroindoles with different substituents in position 1 is described. Microwave-assisted aminolysis of 4-oxo-4,5,6,7-tetrahydrobenzofuran with different primary amines gives the corresponding tetrahydroindoles in few minutes.
New approach for the general synthesis of oxotetrahydroindoles via intramolecular cycloadditions of azomethine ylides with tethered alkynes
Nayyar, Naresh K.,Hutchison, Darrell R.,Martinelli, Michael J.
, p. 982 - 991 (2007/10/03)
A new method for the synthesis of oxotetrahydroindoles has been achieved employing an intramolecular dipolar cycloaddition approach involving mesoionic species (munchnones) with electron-deficient alkynes. The methodology is quite general and convergent as shown by the synthesis of a variety of tri- and tetrasubstituted oxotetrahydroindoles 18, 21, 24, 27, 30, and 34. LiI-based ester cleavage in the presence of an electrophilic acetylenic ketone was critical for formation of the requisite cycloaddition substrates. The cycloaddition is virtually unaffected by the presence of gem-dimethyl groups in the side chain (cf. 38). The presence of a substituted benzyl or a phenethyl moiety on nitrogen, a polarized acetylene, and an appropriate tether between dipole and dipolarophile are essential for obtaining optimal efficiency.
A simple and general synthesis of 4-oxo-4,5,6,7-tetrahydroindoles via a novel intramolecular 1,3-dipolar cycloaddition approach
Hutchison, Darrell R.,Nayyar, Naresh K.,Martinelli, Michael J.
, p. 2887 - 2890 (2007/10/03)
A general synthesis of 4-keto-4,5,6,7-tetrahydroindoles 6-12 has been achieved in two steps using a new intramolecular 1,3-dipolar cycloaddition approach in moderate yields (45-60%). The potential of this methodology is demonstrated by the synthesis of a mitomycin skeleton (15) and a topoisomerase-1 inhibitor skeleton (17).
A FACILE SYNTHESIS OF 4-OXO-4,5,6,7-TETRAHYDROINDOLES
Matsumoto, Masakatsu,Watanabe, Nobuko
, p. 2313 - 2316 (2007/10/02)
Condensation of 1,3-cyclohexanedione with chloroacetaldehyde followed by dehydration gave 4-oxo-4,5,6,7-tetrahydrobenzofuran in a good yield.The tetrahydrobenzofuran was quantitatively converted into 4-oxo-4,5,6,7-tetrahydroindoles.
1,3-Cyclohexanedione derivatives
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, (2008/06/13)
Novel cyclohexanone derivatives of general formula: STR1 (wherein R1 is a hydrocarbon group of 1 to 15 carbon atoms) and new cyclohexanone derivatives of general formula: STR2 (wherein R1 and R2 each is a hydrocarbon group of 1 to 15 carbon atoms) are produced by an electrooxidative coupling of 1,3-cyclohexanedione with a vinyl ether of general formula: (wherein R1 is as defined above) in the presence or absence of an alcohol of general formula: (wherein R2 is as defined above). These new cyclohexanone derivatives can be easily converted to N-substituted or unsubstituted-4-oxo-4,5,6,7-tetrahydroindoles, which are of value as intermediates for the production of N-substituted or unsubstituted-4-hydroxyindoles and, thence, to pindolol and its analogs.
A FACILE SYNTHESIS OF 4-HYDROXYINDOLE VIA ELECTROCHEMICAL OXIDATIVE C-C COUPLING
Torii, Sigeru,Uneyama, Kenji,Onishi, Takashi,Fujita, Yoshiji,Ishiguro, Michihiro,Nishida, Takashi
, p. 1603 - 1604 (2007/10/02)
4-hydroxyindole (1a), a useful intermediate for Pindolol (1b), has been prepared via electrooxidative coupling of 1,3-cyclohexadione with ethyl vinyl ether followed by ammonolysis and dehydrogenation.
