191545-91-2

Upstream product

• 191545-78-5 N-benzyloxycarbonyl-N-benzyl-2-(phenylsulfinyl)ethylamine 
• 2014-75-7 2-(phenylthio)ethanamine 
• 66859-95-8 benzylidene-(2-phenylsulfanyl-ethyl)-amine 
• 67747-34-6 benzyl[2-(phenylsulfanyl)ethyl]amine 
• 100-52-7 benzaldehyde 

Downstream Products

• 142266-67-9 N-benzyloxycarbonyl-1,2,3,4-tetrahydroisoquinoline 
• 91-21-4 1,2,3,4-tetrahydroisoquinoline 

Relevant academic research and scientific papers

An improved synthesis of 1,2,3,4-tetrahydroisoquinolines via intramolecular cyclization of N-acyl-N-(aryl)methyl-2- (phenylsulfinyl)ethylamine by Pummerer reaction

Pummerer reaction of the sulfoxides 5 of N-acyl-N-(aryl)methyl-2- (phenylthio)ethylamines (4) on treatment with trifluoroacetic anhydride (TFAA) effectively caused intramolecular cyclization under a mild condition to give N-acyl-4-phenylthin-1,2,3,4-tetrahydroisoquinolines (TIQs) (7). The reaction of the N-formyl sulfoxide 5c without a methoxy group in the benzene ring using a formyl group for N-protection is particularly efficient. Treatment of the N-formyl sulfoxide 5f with TFAA did not give away TIQ, but a sequential treatment using TFAA and BF3·Et2O afforded N-formyl-4- phenylthio-TIQ (7f) in quantitative yield. The efficiency of this method or preparing TIQs was demonstrated in the synthesis of 1,4-dideuterio-TQ (10D) and its N-methyl derivative (11D).