Benzyl Alcohol → Benzyl 1,2,3,4-tetrahydroisoquinoline-3-carboxylate hydrochloride

Participants

Reaction Conditions

Reaction Steps

Benzyl alcohol, 750 ml, was treated with 150 g of commercial polyphosphoric acid and warmed and stirred at 90° C. to obtain a homogeneous mixture. Solid 1,2,3,4-tetrahydro-3-isoquinolinecarboxylic acid (S-form) 165.2 g was added. The mixture was stirred 4 hours at 95°-105° C. and then allowed to stand at room temperature for 18 hours. A solution of 18.5 g gaseous hydrochloric acid in 2.5 l of anhydrous ether was added, and the product separated slowly on cooling overnight. Filtration gave the crude benzyl 1,2,3,4-tetrahydro-3-isoquinoline carboxylate hydrochloride. This was purified by recrystallization from ethanol twice to give material with mp 190.5°-191° C.; [α]D 23=-83.3° (1% 1:1 methanol/1 N hydrochloric acid).

Provenance & Evidence