2-(3,4-Dimethoxyphenyl)-2-isopropyl-2-(3-iodopropyl)acetonitrile → 3-carboethoxy-3-[4-(3,4-dimethoxyphenyl)-4-isopropyl-4-cyanobutyl]-6,7-dimethoxy-N-methyl-1,2,3,4-tetrahydroisoquinoline

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Reaction Steps

The resulting ester of formula 31 is then treated with an iodoalkane of formula 22 (see Scheme III, step 2) in the presence of a strong base to form an alkylated tetrahydroisoquinoline ester of formula 32. For example, 3-carboethoxy-6,7-dimethoxy-N-methyl-1,2,3,4-tetrahydroisoquinoline (31) is added to a solution of LDA in THF at -70° C. and allowed to stand for 5-60 minutes, preferably about 10 minutes. To this reaction mixture is then added 2-(3,4-dimethoxyphenyl)-2-isopropyl-2-(3-iodopropyl)acetonitrile (22) in THF, and the resulting mixture allowed to warm to about 0° C. The mixture is then acidified, for example with dilute HCl, and the product extracted and purified to produce 3-carboethoxy-3-[4-(3,4-dimethoxyphenyl)-4-isopropyl-4-cyanobutyl]-6,7-dimethoxy-N-methyl-1,2,3,4-tetrahydroisoquinoline (32).

Provenance & Evidence