20232-47-7

Upstream product

• 33329-41-8 6,7-dimethoxy-3-(3,4-dimethoxyphenyl)-1,2,3,4-tetrahydroisoquinoline 
• 100-97-0 hexamethylenetetramine 
• 5471-40-9 3,4,3',4'-tetramethoxy-bibenzyl-α-ylamine 
• 135365-11-6 5-(3,4-Dimethoxy-phenyl)-8,9-dimethoxy-6,10b-dihydro-5H-oxazolo[2,3-a]isoquinoline-2,3-dione 
• 76306-70-2 N-<1,2-bis(3,4-dimethoxyphenyl)ethyl>formamide 
• 4927-55-3 1,2-bis(3,4-dimethoxyphenyl)ethanone 

Downstream Products

• 69504-70-7 3-(3,4-dimethoxyphenyl)-6,7-dimethoxyisoquinoline 

Relevant academic research and scientific papers

Application of hexamethylenetetramine in a Pictet-Spengler type reaction for synthesis of isoquinoline derivatives

Hexamethylenetetramine was used successfully as amino- and amidoalkylation cyclization reagent for the synthesis of 3,4-dihydroisoquinolines, tetrahydroisoquinolines and 1,4-dihydro-3(2H)-isoquinolinones. The reagent provides a simple and convenient pathway for the preparation of a range of these compounds.

A Modified Bischler-Napieralski Procedure for the Synthesis of 3-Aryl-3,4-dihydroisoquinolines

A modification of the Bischler-Napieralski reaction for the cyclization of (1,2-diphenylethyl)amides to the 3-aryl-3,4-dihydroisoquinolines is presented.Elimination of the amide group as the nitrile via the retro-Ritter reaction is avoided by its conversion to an N-acyliminium intermediate with oxalyl chloride-FeCl3.Removal of the oxalyl group in refluxing MeOH-sulfuric acid provides the 3,4-dihydroisoquinolines in moderate to high yields.The method is also highly effective with (2-phenylethyl)amides.

Dehydrogenation Reactions of 1-Substituted-3-Aryltetrahydroisoquinoline Derivatives

The 1-substituted-3-aryltetrahydroisoquinolines I have been converted into the corresponding 3,4-dihydro- or isoquinoline derivatives by treatment with several oxidizing agents: iodine in ethanol, palladium on carbon, DDQ and Fremy's salt.The oxidation re

Unusual Products in Bischler-Napieralski Reaction

Bischler-Napieralski cyclisation of the benzoyl and acetyl derivatives (I and II) using PCl5 gives the dihydroisoquinolines only when these derivatives have no dimethoxy or methylenedioxy substituents in the α-phenyl ring.All the formyl derivatives (III), however, give the dihydroisoquinolines in good yield.Stilbenes (VII), meso-stilbene dichlorides (VIII) and the hydrindane derivative (X) are obtained as neutral products in the above reactions, sometimes as the sole products.The results clearly demonstrate the occurrence of side raections in this cyclisation reaction even when there are activating groups favouring cycldehydration.