Syntheses of chiral 1,3-disubstituted tetrahydro-β-carbolines via CIAT process: highly stereoselective Pictet–Spengler reaction of d-tryptophan ester hydrochlorides with various aldehydes
摘要:
A highly stereoselective Pictet-Spengler reaction of D-tryptophan methyl ester hydrochloride 1-HCl with various aldehydes via a CIAT (crystallization-induced asymmetric transformation) process is described. It was revealed that the CIAT process should be performed in a mixed solvent of nitromethane and toluene, and a fine tuning of the ratio of nitromethane and toluene for each epimer Mixture of 2-HCl was necessary in order to get as high yields and stereoselectivities as possible. Enantiomerically pure cis (or trans) 1,3-disubstituted tetrahydro-beta-carbolines 2a-2v were obtained by recrystallization or flash chromatography after neutralization of the corresponding hydrochloride salts cis-2-HCl or trans-2-HCl. (c) 2009 Elsevier Ltd. All rights reserved.
CONVERSION OF TRYPTOPHAN INTO BETA-CARBOLINE DERIVATIVES
申请人:Pirc Samo
公开号:US20110105751A1
公开(公告)日:2011-05-05
The invention belongs in the field of organic chemistry and relates to a new shortened Pictet-Spengler type reaction for preparing isomerically pure β-carboline compounds useful for the synthesis of tadalafil.
Conversion of tryptophan into ß-carboline derivatives
申请人:LEK Pharmaceuticals d.d.
公开号:EP2107059A1
公开(公告)日:2009-10-07
The invention belongs in the field of organic chemistry and relates to a new shortened Pictet-Spengler type reaction for preparing isomerically pure β-carboline compounds useful for the synthesis of tadalafil.
Syntheses of chiral 1,3-disubstituted tetrahydro-β-carbolines via CIAT process: highly stereoselective Pictet–Spengler reaction of d-tryptophan ester hydrochlorides with various aldehydes
A highly stereoselective Pictet-Spengler reaction of D-tryptophan methyl ester hydrochloride 1-HCl with various aldehydes via a CIAT (crystallization-induced asymmetric transformation) process is described. It was revealed that the CIAT process should be performed in a mixed solvent of nitromethane and toluene, and a fine tuning of the ratio of nitromethane and toluene for each epimer Mixture of 2-HCl was necessary in order to get as high yields and stereoselectivities as possible. Enantiomerically pure cis (or trans) 1,3-disubstituted tetrahydro-beta-carbolines 2a-2v were obtained by recrystallization or flash chromatography after neutralization of the corresponding hydrochloride salts cis-2-HCl or trans-2-HCl. (c) 2009 Elsevier Ltd. All rights reserved.