Sulfuric Acid → 1,2,3,4-Tetrahydroisoquinolin-7-ol

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A solution of 1,2,3,4-tetrahydro-isoquinolin-7-amine (4.5 g, 30 mmol) in sulfuric acid (6.5 mL, 120 mmol) and water (20 mL) was cooled to 0° C. To this cold solution was added a solution of sodium nitrite (2.51 g, 36 mmol) in water (20 mL) over 15 min. After the addition, the reaction mixture was heated at 120° C. for 2 h and then allowed to cool to rt. Solid Na2CO3 was added slowly to the reaction mixture until no gas generated. A small amount of water was added to dissolve the remaining Na2CO3 and a sticky brown glue was formed. The residue was dissolved in MeOH and filtered through Celite. The filtrate was concentrated to give 1,2,3,4-tetrahydroisoquinolin-7-ol as a brown solid (3.7 g, 82% crude yield), which was directly used in the next step without further purification. MS: 150.

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