Formaldehyde → HCID 59744272, compound

Participants

Reaction Steps

The synthesis of 6,7-dimethoxy-1-[4-(4-methoxypyridin-3-yl)benzyl]-2-methyl-1,2,3,4-tetrahydroisoquinoline hydrochloride 23 is shown in Scheme 6. 6,7-Dimethoxy-1-[4-(4-methoxypyridin-3-yl)benzyl]-3,4-dihydro-1H-isoquinoline-2-carboxylic acid tert-butyl ester 20 was prepared by the reaction of 1-(4-bromobenzyl)-6,7-dimethoxy-3,4-dihydro-1H-isoquinoline-2-carboxylic acid tert-butyl ester 1 with 4-methoxypyridine-3-boronic acid 19 in the presence of Palladium(II) acetate, triphenylphosphine, and Na2CO3 in anhydrous isopropanol. Reaction of compound 20 with 2 M HCl solution in diethylether gave 6,7-dimethoxy-1-[4-(4-methoxypyridin-3-yl)benzyl]-1,2,3,4-tetrahydroisoquinolinehydrochloride salt 21. Reaction of 21 with formaldehyde, sodium cyanoborohydride, and zinc chloride in methanol furnished 6,7-dimethoxy-1-[4-(4-methoxypyridin-3-yl)benzyl]-2-methyl-1,2,3,4-tetrahydroisoquinoline 22 which was then reacted with 2 M HCl solution in diethylether to yield the compound 23.

Provenance & Evidence