反应详情

Esterification: To a suspension of (S)-7-hydroxy-1,2,3,4-tetrahydro-isoquinoline-3-carboxylic acid dehydrate (109 mmol) in methanol (150 mL) was added hydrochloric acid (27 ml, of 4M solution in dioxane) at r.t and the reaction mixture was refluxed for 4 h. The mixture was concentrated, resuspeneded in 150 mL of MeOH and hydrochloric acid (27 mL of 4M solution in dioxane) added. The mixture refluxed for 4 h and was concentrated under reduced pressure. The residue was triturated with ether, filtered and washed with ether to give (S)-7-hydroxy-1,2,3,4-tetrahydro-isoquinoline-3-carboxylic acid methyl ester hydrochloride salt (25.1 g). 1H NMR (400 MHz, DMSO d6): 10.1 (m, 2H), 9.62 (s, 1H), 7.03 (d, 1H), 6.7 (m, 1H), 6.26 (d, 1H), 4.48 (m, 1H), 4.21 (s, 2H), 3.77 (s, 3H), 3.17-2.96 (m, 2H).

1. temperaturethe reaction mixture was refluxed for 4 h
2. concentrationThe mixture was concentrated
3. additionhydrochloric acid (27 mL of 4M solution in dioxane) added
4. temperatureThe mixture refluxed for 4 h
5. concentrationwas concentrated under reduced pressure
6. customThe residue was triturated with ether
7. filtrationfiltered
8. washwashed with ether