Reaktion #42547

Reaktionsgleichung

2-tert-butyl 7-methyl 1-butyl-3,4-dihydroisoquinoline-2,7(1H)-dicarboxylate

lithium hydroxide monohydrate

→

2-(tert-butoxycarbonyl)-1-butyl-1,2,3,4-tetrahydroisoquinoline-7-carboxylic acid

Ausbeute 61.5%

Lösungsmittel

dioxane methanol water

Reaktionsbedingungen

Aufarbeitung

1. 1
   EinengenThe reaction mixture was concentrated under reduced pressure
2. 2
   Sonstigethe solid residue partitioned between ethyl acetate and water
3. 3
   Extraktionextracted several times with 3:1 chloroform/2-propanol
4. 4
   WaschenThe combined organic phases were washed with water and saturated sodium chloride
5. 5
   Trocknendried (sodium sulfate)
6. 6
   Filtrationfiltered
7. 7
   Einengenconcentrated under reduced pressure

Vorschrift

To a solution of 2-tert-butyl 7-methyl 1-butyl-3,4-dihydroisoquinoline-2,7(1H)-dicarboxylate prepared in step 2 (347 mg, 1.0 mmol) in 2:1:1 dioxane/methanol/water (6.6 mL) was added lithium hydroxide monohydrate (125 mg, 3.0 mmol) and the reaction mixture stirred 24 h at room temperature. The reaction mixture was concentrated under reduced pressure and the solid residue partitioned between ethyl acetate and water. The aqueous phase was acidified with 1 N hydrochloric acid to pH 1 and extracted several times with 3:1 chloroform/2-propanol. The combined organic phases were washed with water and saturated sodium chloride, dried (sodium sulfate), filtered, and concentrated under reduced pressure to provide 2-(tert-butoxycarbonyl)-1-butyl-1,2,3,4-tetrahydroisoquinoline-7-carboxylic acid (205 mg). ESI MS m/z 332 [M−H]−.

Quelle