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

HRID 650068Notes

Reaction equation

HRID 650068 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

Reactant 3

HCID 8028TetrahydrofuranHCID 4311764Sodium borohydrideHCID 15432798ethyl 5,6-dihydro-9-methyl-6-oxo-4H-pyrrolo [3,2,1-ij]quinoline-2-carboxylate

Product 1

HCID 21714278ethyl 5,6-dihydro-6-hydroxy-9-methyl-4H-pyrrolo [3,2,1-ij]quinoline-2-carboxylateYield 79.1%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

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-09810b515f63469fabb29e1d6ed7f06e
Source dataset
uspto-grants-2001_08
Patent number
US06271251B1

Reaction notes

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