31756-16-8

Upstream product

• 3382-18-1 6,7-dimethoxy-3,4-dihydro-isoquinoline 
• 7306-46-9 4-chloromethyl-1,2-dimethoxy-benzene 

Downstream Products

• 523-02-4 2,3,10,11-tetramethoxy-5,6,7,8,13,13a-hexahydroisoquinolino[3,2-a]isoquinoline 
• 220935-99-9 2-(3,4-Dimethoxy-benzyl)-6,7-dimethoxy-1,2,3,4-tetrahydro-isoquinoline-1-carboxylic acid methyl ester 
• 220935-98-8 1-carbamoyl-2-(3,4-dimethoxybenzyl)-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline 
• 76800-86-7 6,7-dimethoxy-2-veratryl-1,2,3,4-tetrahydro-isoquinoline-1-carbonitrile 
• 75875-53-5 2-(3,4-Dimethoxy-benzyl)-1-(methanesulfinyl-methylsulfanyl-methyl)-6,7-dimethoxy-1,2,3,4-tetrahydro-isoquinoline 

Relevant academic research and scientific papers

(±)-Heterocarpine, a hydroxymethylated isoquinoline alkaloid from Ceratocapnos heterocarpa

Heterocarpine, a novel alkaloid from Ceratocapnos heterocarpa, has been characterised as (±)-1-hydroxymethyl-2-(3-hydroxy-4-methoxybenzyl)-7- hydroxy-6-methoxy-1,2,3,4-tetrahydroisoquinoline. The alkaloid was synthesized from the corresponding 3,4-dihydro isoquinoliniun salt. A key step in the process is the acid resin catalysed methanolysis of the 1- carbamoyl isoquinoline. The structural correlation of the hydroxymethylated alkaloids heterocarpine and malacitanine with their unsubstituted counterparts capnosine and caseamine, also present in the plant, might be of biosynthetic significance.

A regiospecific synthesis of protoberberine alkaloids

The protoberberine skeleton has been prepared in two steps from N-benzyl-3,4-dihydroisoquinolinium salts.Treatment of the salts with the anion of methyl methylthiomethylsulfoxide yields mixtures of diastereomeric adducts that cyclize on heating with concentrated hydrochloric acid to dihydroprotoberberines.The latter compounds may be reduced to their tetrahydro analogues with sodium borohydride, oxidized to protoberberinium salts with iodine, or converted to 13-methyltetrahydroprotoberberines by treatment with formaldehyde according to an established procedure.The method has been applied successfully to the synthesis of (+/-)-tetrahydropalmatine, palmatine iodide, (+/-)-xylopinine, (+/-)-sinactine, and (+/-)-corydaline.N-Benzylisoquinolinium salts may be used in place of their dihydro analogues as starting materials in this synthesis, thereby extending the range of substitution patterns potentially available.