8-(Phenylmethylidene)-5,6,7,8-tetrahydroquinoline → 6,7-Dihydro-5H-quinoline-8-one

HRID 252080Notes

Reaction equation

HRID 252080 reaction equation
C(=[C:8]1[C:17]2[N:16]=[CH:15][CH:14]=[CH:13][C:12]=2[CH2:11][CH2:10][CH2:9]1)C1C=CC=CC=1.[O:18]=[O+][O-].O=O>ClCCl.CO>[N:16]1[C:17]2[C:8](=[O:18])[CH2:9][CH2:10][CH2:11][C:12]=2[CH:13]=[CH:14][CH:15]=1

Participants

5

Reactant 2

HCID 540746508-(Phenylmethylidene)-5,6,7,8-tetrahydroquinolineHCID 131711318Oxygen ozone

Product 1

HCID 117447776,7-Dihydro-5H-quinoline-8-one

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 6344DichloromethaneSolvent

Conditions

Temperature
0 °C

Procedure

A solution of (2) in dichloromethane (100 mL) and methanol (500 mL) was cooled to −78° C. and charged with ozone/oxygen (3 psi, 1.5 ampere). The dark brown solution turned yellow after several hours. When (2) was consumed (TLC), ozone/oxygen flow was stopped. The reaction mixture was purged with nitrogen for 10 m. Methyl sulfide (6 mL) was added, and the mixture was stirred for 30 m at 0° C. The solvents were removed under vacuum and the residue was dissolved in 1 N HCl (500 mL) and washed with diethyl ether (4×150 mL). The aqueous layer was basified to pH ˜7 with NaOH (s), and extracted with ethyl acetate (2×200 mL). The pooled ethyl acetate layers were dried over magnesium sulfate. The mixture was filtered and the solvent was removed under vacuum. The residue was purified by chromatography on silica gel with 90% EtOAc 10% hexane to give 6,7-Dihydro-5H-quinolin-8-one (3) as a solid. The aqueous layer was extracted with chloroform/isopropanol (3:1) several times. The pooled chloroform/isopropanol layers were dried over magnesium sulfate. The mixture was filtered and the solvents were removed under vacuum to give (3). The combined weight of (3) was 17.9 g (122 mmol, 89% over 2 steps).

Workup

  1. waitThe dark brown solution turned yellow after several hours
  2. customWhen (2) was consumed (TLC), ozone/oxygen flow
  3. customThe reaction mixture was purged with nitrogen for 10 m
  4. additionMethyl sulfide (6 mL) was added
  5. customThe solvents were removed under vacuum
  6. dissolutionthe residue was dissolved in 1 N HCl (500 mL)
  7. washwashed with diethyl ether (4×150 mL)
  8. extractionextracted with ethyl acetate (2×200 mL)
  9. dry with materialThe pooled ethyl acetate layers were dried over magnesium sulfate
  10. filtrationThe mixture was filtered
  11. customthe solvent was removed under vacuum
  12. customThe residue was purified by chromatography on silica gel with 90% EtOAc 10% hexane

Sources & evidence

ORD record
ord-667d347cbb3e40f5b589534c3ec0952a
Source dataset
uspto-grants-2011_01
Patent number
US07868020B2

Reaction notes

Loading…