Diethyl Oxalate → Methyl 2-oxo-2-(1-oxo-6-vinyl-1,2,3,4-tetrahydronaphthalen-2-yl)acetate

HRID 1506389Notes

Reaction equation

HRID 1506389 reaction equation
[CH:1]([C:3]1[CH:4]=[C:5]2[C:10](=[CH:11][CH:12]=1)/[C:9](=N/O)/[CH2:8][CH2:7][CH2:6]2)=[CH2:2].[C:15]([O:22][CH2:23]C)(=[O:21])[C:16]([O:18]CC)=O.C[O-:26].[Na+]>CO>[O:18]=[C:16]([CH:8]1[CH2:7][CH2:6][C:5]2[C:10](=[CH:11][CH:12]=[C:3]([CH:1]=[CH2:2])[CH:4]=2)[C:9]1=[O:26])[C:15]([O:22][CH3:23])=[O:21]

Participants

5

Reactant 3

HCID 7268Diethyl OxalateHCID 10942334Sodium MethoxideHCID 121012766(NE)-N-(6-ethenyl-3,4-dihydro-2H-naphthalen-1-ylidene)hydroxylamine2×

Product 1

HCID 67171899Methyl 2-oxo-2-(1-oxo-6-vinyl-1,2,3,4-tetrahydronaphthalen-2-yl)acetate

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

To a 250 mL round bottom flask charged with a solution of 6-vinyl-3,4-dihydronaphthalen-1(2H)-one (intermediate 1, 400 mg, 2.323 mmol) and diethyl oxalate (0.630 mL, 4.65 mmol) in methanol (20 mL) was added sodium methoxide (25% wt in MeOH) (2008 mg, 9.29 mmol) via syringe. After the addition was complete, the dark reaction mixture was heated at reflux for 10 h. The reaction was quenched with 50% HCl aq. solution and then evaporated to remove the methanol. The aqueous residue was diluted with water (80 mL) and extracted with dichloromethane (2×100 ml). The organic layers were combined, concentrated, and purified by silica gel chromatography, (40 g Isco column, 0% to 25% ethyl acetate in hexane gradient) to yield the title compound. The compound had an HPLC ret. time=1.05/2.0 min. (condition E); MS:(M+H)=259.1.

Workup

  1. additionAfter the addition
  2. customthe dark reaction mixture
  3. temperaturewas heated
  4. temperatureat reflux for 10 h
  5. customThe reaction was quenched with 50% HCl aq. solution
  6. customevaporated
  7. customto remove the methanol
  8. additionThe aqueous residue was diluted with water (80 mL)
  9. extractionextracted with dichloromethane (2×100 ml)
  10. concentrationconcentrated
  11. custompurified by silica gel chromatography, (40 g Isco column, 0% to 25% ethyl acetate in hexane gradient)

Sources & evidence

ORD record
ord-939a08443a9a49b8a7c0b8fe362862f5
Source dataset
uspto-grants-2015_12
Patent number
US09216972B2

Reaction notes

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