Efficient and Practical One-Pot Conversions of N-Tosyltetrahydroisoquinolines into Isoquinolines and of N-Tosyltetrahydro-β-carbolines into β-Carbolines through Tandem β-Elimination and Aromatization
An efficient, practical, and general method for conversions of N-tosyltetrahydroisoquinolines (N-tosyl-THIQs) into isoquinolines and of N-tosyltetrahydro-β-carbolines (N-tosyl-THBCs) into β-carbolines is described. Treatment of N-tosyl-THIQs or N-tosyl-THBCs with base in dimethyl sulfoxide afforded dihydroisoquinolines or dihydro-β-carbolines as intermediates, and these were then oxidized in situ by
In the present work, a practicalsynthesis of 1-aryl-β-carboline-3-carbaldehydes as versatile building blocks and their application in Biginelli reaction is reported. The starting material of the four-step synthesis is racemic tryptophan methyl ester. The procedure involves a Pictet–Spengler cyclization, a dehydrogenation, an ester reduction, and an alcohol oxidation step. The β-carboline-3-carbaldehydes
Manufacturing process for Tadalafil from racemic or L-tryptophan
申请人:Soukup Milan
公开号:US20120123124A1
公开(公告)日:2012-05-17
The present invention relates to a novel manufacturing process of pharmaceutically active compound of formula I, having (6R,12aR)-configuration, used for treatment of erectile dysfunction. Starting from racemic or L-tryptophan the invention describes preparation of an enantiomerically pure intermediate of formula II which is a known precursor in the synthesis of Tadalafil (formula I).
[EN] MODIFIED PICTET-SPENGLER REACTION AND PRODUCTS PREPARED THEREFROM<br/>[FR] REACTION DE PICTET-SPENGLER MODIFIEE ET PRODUITS PREPARES A PARTIR DE CETTE DERNIERE
申请人:LILLY ICOS LLC
公开号:WO2004011463A1
公开(公告)日:2004-02-05
A method of introducing a second stereogenic center into a tetrahydro-ß-carboline have two stereogenic centers using a modified Pictet-Spengler reaction is disclosed. The method provides a desired cis- or trans-isomer in high yield and purity, and in short processes times.
[EN] PROCESS FOR THE PREPARATION OF 2,3,4,9-TETRAHYDRO-1H-BETA-CARBOLIN-3-CARBOXYLIC ACID ESTERS"<br/>[FR] PROCÉDÉ DE PRÉPARATION D'ESTERS DE L'ACIDE 2,3,4,9-TÉTRAHYDRO-1H-BÊTA-CARBOLIN-3-CARBOXYLIQUE
申请人:ENDURA SPA
公开号:WO2009103787A1
公开(公告)日:2009-08-27
The present invention relates to the process of preparation of 2,3,4,9-tetrahydro- 1 /-/-β-carbolin-3-carboxylic acid esters substituted in position 1 of the general formula (I). in the preferred diastereoisomeric form through a single step starting from tryptophan in racemic form and/or its enantiomers and from 3,4-(methylenedioxy)benzaldehyde.