Tetrahydrofuran → ethyl 5,6-dihydro-6-hydroxy-9-methyl-4H-pyrrolo [3,2,1-ij]quinoline-2-carboxylate

HRID 355707Notes

Reaction equation

HRID 355707 reaction equation
[CH3:1][C:2]1[C:11]2[CH:12]=[C:13]([C:14]([O:16][CH2:17][CH3:18])=[O:15])[N:9]3[C:10]=2[C:5]([C:6](=[O:19])[CH2:7][CH2:8]3)=[CH:4][CH:3]=1.O1CCCC1.[BH4-].[Na+]>C(O)C>[OH:19][CH:6]1[C:5]2[C:10]3=[C:11]([CH:12]=[C:13]([C:14]([O:16][CH2:17][CH3:18])=[O:15])[N:9]3[CH2:8][CH2:7]1)[C:2]([CH3:1])=[CH:3][CH:4]=2

Participants

5

Conditions

Temperature
0 °C

Procedure

Ethyl 5,6-dihydro-9-methyl-6-oxo-4H-pyrrolo [3,2,1-ij]quinoline-2-carboxylate (3.00 g, 11.7 mmol) was added to a mixture of tetrahydrofuran (20 ml) and ethanol (80 ml), and the reaction mixture was cooled to 0° C. Then, sodium borohydride (0.44 g, 11.7 mmol) was added and the resulting mixture was stirred at 0° C. for 1 hour. The reaction mixture was concentrated under reduced pressure, and ethyl acetate and then a 5% aqueous sodium hydroxide solution were added to the residue. After being separated, the aqueous layer was further extracted twice with ethyl acetate, and the combined organic layer was washed with a 5% aqueous sodium chloride solution and dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure and the resulting residue was purified by a silica gel column chromatography (eluent: ethyl acetate/n-hexane= 1/9) to obtain 2.40 g of ethyl 5,6-dihydro-6-hydroxy-9-methyl-4H-pyrrolo [3,2,1-ij]-quinoline-2-carboxylate.

Workup

  1. concentrationThe reaction mixture was concentrated under reduced pressure, and ethyl acetate
  2. additiona 5% aqueous sodium hydroxide solution were added to the residue
  3. customAfter being separated
  4. extractionthe aqueous layer was further extracted twice with ethyl acetate
  5. washthe combined organic layer was washed with a 5% aqueous sodium chloride solution
  6. dry with materialdried over anhydrous magnesium sulfate
  7. distillationThe solvent was distilled off under reduced pressure
  8. customthe resulting residue was purified by a silica gel column chromatography (eluent: ethyl acetate/n-hexane= 1/9)

Sources & evidence

ORD record
ord-981266df9bc54510b574048aa4468d9d
Source dataset
uspto-grants-1998_11
Patent number
US05834454

Reaction notes

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