Reaktion #1547381

Reaktionsgleichung

water

product

Ethyl (±)-[2-(3',4'-dihydro-2'-hydroxyspiro-[cyclopentane-1,1'(2'H)-napthalen]-2'-yl)ethyl]-carbamate

sulfuric acid

acetic acid

→

title compound

Ausbeute 59.0%

Ethyl (±)-2,3,4,5-tetrahydro-3a,9b-butano-1H-benz[g]indole-1-carboxylate

Ausbeute 59.0%

Reaktionsbedingungen

Aufarbeitung

1. 1
   Extraktionthe resulting mixture was extracted with CH2Cl2 (4×30 mL)
2. 2
   TrocknenThe combined organic extracts were dried (MgSO4)
3. 3
   Filtrationfiltered
4. 4
   Einengenconcentrated
5. 5
   workup.DISSOLUTIONThe residue was dissolved in CH2Cl2 (100 mL
6. 6
   Waschenwashed with saturated aq. bicarbonate solution (30 mL)
7. 7
   TrocknenThe organic phase was dried (MgSO4)
8. 8
   Filtrationfiltered
9. 9
   Einengenconcentrated
10. 10
    SonstigeThe residue was purified by chromatography (silica gel, 9:1 heptane/ethyl acetate)

Vorschrift

A solution of the product from Example 13 (1.68 g, 5.29 mmol) in 15 mL of 3:1 acetic acid/concentrated sulfuric acid (v/v) was stirred at room temperature for 18 hours. The reaction mixture was poured into water (50 mL) and the resulting mixture was extracted with CH2Cl2 (4×30 mL). The combined organic extracts were dried (MgSO4), filtered and concentrated. The residue was dissolved in CH2Cl2 (100 mL and washed with saturated aq. bicarbonate solution (30 mL). The organic phase was dried (MgSO4), filtered and concentrated. The residue was purified by chromatography (silica gel, 9:1 heptane/ethyl acetate) to give the title compound (0.94 g, 59%) as a white solid mp 67°-69° C.

Quelle