1453863-98-3

Upstream product

• 3163-27-7 2-(bromomethyl)naphthalene 
• 238428-10-9 (1S,3S)-methyl 1-(4-fluorophenyl)-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole-3-carboxylate 

Downstream Products

• 1453864-10-2 (1S,3R)-methyl 1-(4-fluorophenyl)-2-(naphthalen-1-ylmethyl)-1,2,3,4-tetrahydro-9H-pyrido[3,4-b]indole-3-carboxylate 

Relevant academic research and scientific papers

Highly stereoselective transformation of (1S,3S)-cis-1,3-disubstituted tetrahydro-β-carbolines into (1S,3R)-trans-1,3-disubstituted tetrahydro-β-carbolines: An improved asymmetric synthesis of tadalafil from l-tryptophan

An efficient and general method for the highly stereoselective transformation of (1S,3S)-cis-1,3-disubstituted 1,2,3,4-tetrahydro-β- carbolines (THBCs) into (1S,3R)-trans-1,3-disubstituted THBCs is described. The method contains the following three steps: the enantiomerically pure (1S,3S)-cis-1,3-disubstituted THBCs 1 were first converted into (1S,3S)-cis-1,2,3-trisubstituted THBCs 2 by N-1-naphthylmethylation/benzylation; (1S,3S)-cis-1,2,3-trisubstituted THBCs2 were then converted into (1S,3R)-trans-1,2,3-trisubstituted THBCs 3 in high yields and with high stereoselectivities via a base-catalyzed epimerization at C-3; (1S,3R)-trans-1,2,3-trisubstituted THBCs 3 were subsequently converted into (1S,3R)-trans-1,3-disubstituted THBCs 4 after reductive removal of the 1-naphthylmethyl/benzyl group. In addition, as an application of this method, an improved and highly stereoselective synthesis of the PDE5 inhibitor tadalafil (Cialis) starting from natural and less expensive l-tryptophan was developed.