261729-91-3

Upstream product

• 5042-53-5 1-(phenylsulfanyl)acetone 
• 2627-86-3 (S)-1-phenyl-ethylamine 
• 261729-79-7 (R)-N-benzyloxycarbonyl-1-methyl-2-phenylsulfanylethylamine 
• 3111-52-2 potassium thiophenolate 
• 3886-69-9 (R)-1-phenyl-ethyl-amine 
• 122673-69-2 (R)-1-methyl-2-phenylsylfanylethylamine 
• 98-86-2 acetophenone 

Downstream Products

• 261729-95-7 N-[(R)-1-methyl-2-phenylsulfanylethyl]-N-[(R)-1-phenylethyl]formamide 
• 261730-13-6 (1R,3R)-1,3-dimethyl-4-(phenylsulfanyl)-1,2,3,4-tetrahydroisoquinoline-2-carbaldehyde 
• 261729-99-1 N-[(1R)-1-methyl-2-(phenylsulfinyl)ethyl]-N-[(1R)-1-phenylethyl]formamide 
• 637040-73-4 (1R,3R,4S)-1,3-dimethyl-4-phenyl-1,2,3,4-tetrahydroisoquinoline-2-carbaldehyde 

Relevant academic research and scientific papers

Super acid-induced pummerer-type cyclization reaction: Improvement in the synthesis of chiral 1,3-dimethyl-1,2,3,4-tetrahydroisoquinolines

Improved synthesis of four stereoisomeric chiral 1,3-dimethyl-1,2,3,4- tetrahydroisoquinolines (1a, b, ent-1a, b) was achieved via the super acid-induced cyclization of chiral N-[1-methyl-2-(phenylsulfinyl)ethyl]-N-(1- phenylethyl)formamides (4a, b, ent-4a, b) using the Pummerer-type cyclization reaction as a key step. The cyclization leading to the isoquinoline ring proceeded in a quantitative manner when trifluoromethane sulfonic acid (TFSA) was used as the super acid, although Friedel-Crafts-type alkylation of 4-phenylsulfanyl TIQ derivatives (5) with benzene used as the solvent accompanied cyclization to yield the 4-phenyl-TIQs (7). The byproduct (7) was exclusively formed when a large excess amount of TFSA was used.

A Chiral Synthesis of Four Stereoisomers of 1,3-Dimethyl-1,2,3,4-tetrahydroisoquinoline, an Inducer of Parkinson-like Syndrome

Four stereoisomers of 1,3-dimethyl-1,2,3,4-tetrahydroisoquinoline, an inducer of Parkinson-like syndrome, were synthesized by applying a new method of 1,2,3,4-tetrahydroisoquinoline (TIQ) synthesis utilizing the Pummerer reaction as a key step. The chiral centers at C-1 and C-3 were constructed by two routes starting from alaninol (3) and 1-phenylethylamine (4) as a chiral source. Enantiomerically pure 1,3-dimethyl-TIQs (1R,3S)-(1), (1S,3R)-(ent-1), (1S,3S)-(2), and (1R,3R)-(ent-2) were prepared in a stereochemically unambiguous manner from 3 in 11 steps (route I) and from 4 in 6 steps (route II). The conformations of tetrahydroisoquinoline ring in 1-methyl, 3-methyl, and 1,3-dimethyl-TIQs were discussed on the basis of their CD, 1H-NMR spectra, and steric energies.