56666-88-7Relevant articles and documents
A new synthesis of 4-oxygenated β-carboline derivatives by Fischer indolization
Suzuki, Hideharu,Tsukakoshi, Yoshiyuki,Tachikawa, Takuya,Miura, Yuusuke,Adachi, Makoto,Murakami, Yasuoki
, p. 3831 - 3834 (2007/10/03)
A new and short synthetic route to the 4-methoxy-β-carboline skeleton is described. The route involves Fischer indolization of enehydrazine of 1-tosylpiperidine-3,5-dione and successive acetalization-elimination for aromatization of 1,2,3,4-tetrahydro-2-tosyl-9H-β-carbolin-4-one. This method is efficiently applicable to synthesis of the benzene-part substituted 4-oxygenated β-carboline derivatives.
A general synthetic route for 1-substituted 4-oxygenated β-carbolines (synthetic studies on indoles and related compounds 41)
Suzuki, Hideharu,Iwata, Chiemi,Sakurai, Katsumi,Tokumoto, Kazuhiko,Takahashi, Hiroko,Hanada, Masako,Yokoyama, Yuusaku,Murakami, Yasuoki
, p. 1593 - 1606 (2007/10/03)
A new synthetic route for two naturally occurring 1-substituted 4-methoxy-β-carbolines (1b, c) is described. This synthetic route involves elaboration of the ester groups in ethyl indole-2-carboxylate (4b) and its 1-benzyl derivative (4a), C3-s
Unexpected Debenzylation of N-Benzylindoles with Lithium Base. A New Method of N-Debenzylation
Suzuki, Hideharu,Tsukuda, Akiko,Kondo, Mika,Aizawa, Miki,Senoo, Yumiko,et al.
, p. 1671 - 1672 (2007/10/02)
The reaction of N-benzylindoles with lithium base resulted in debenzylation.The key step would be generation of benzyl carbene from the preformed N-benzyl anion.This reaction should serve as a new debenzylation method for indoles and related compounds.
A new general synthetic route for 1-substituted 4-oxygenated β-carbolines
Suzuki,Yokoyama,Miyagi,Murakami
, p. 2170 - 2172 (2007/10/02)
Two natural]y occurring 1-substituted 4-methoxy-β-carboline (1b,c) were synthesized from ethyl indole-2-carboxylate (5b) and its 1-benzyl derivative (5a), respectively. The synthesis routes involved elaboration of the ester group of 5a,b, cyclization of t
DDQ Oxidations in the Indole Area. Synthesis of 4-Alkoxy-β-carbolines Including the Natural Products Crenatine and 1-Methoxycanthin-6-one
Hagen, Timothy J.,Narayanan, Krishnaswamy,Names, Jeffrey,Cook, James M.
, p. 2170 - 2178 (2007/10/02)
The seven-step synthesis of the cytotoxic, antileukemic alkaloid 1-methoxycanthin-6-one (2b) is described.The pivotal steps are represented by the oxidation (DDQ, aqueous THF, room temperature) of 1-(methoxycarbonyl)-1,2,3,4-tetrahydro-β-carboline (10) to provide the 4-oxo-substituted derivative 14 in 78percent yield, and conversion of the 4-oxo analogue 7 into 4-methoxy-1-alkyl-β-carboline (23) via a methoxylation-oxidation process .This four-step, one-pot reaction has been shown to be general; 4-oxo-1,2,3,4-tetrahydro-β-carboline (18) was converted into the corresponding 4-methoxy-, 4-ethoxy-, 4-(allyloxy)-, and 4-(benzyloxy)-β-carbolines (19a-d, respectively) on heating in the appropriate alcohol in the presence of pTSA and a trialkyl orthoformate (Table II).The proposed mechanism for this intriguing transformation is outlined in Scheme IV.Execution of this process has also resulted in a four-step preparation of crenatine (1a), a 4-methoxy-1-ethyl-β-carboline alkaloid.Finally, steric and electronic parameters have also been successfully manipulated to direct the DDQ oxidation of 1,2,3,4-tetrahydro-β-carbolines to position 1, regiospecifically.The conversion of tetrahydro-β-carboline 25 into 2-acylindole 38 and benzamide 26 into 1-oxotetrahydro-β-carboline 27 (Table I), respectively, is in agreement with the proposed mechanism for this process.
