Hydrochloric Acid → ethyl 1-oxo-1,2,3,4-tetrahydronaphthalene-2-carboxylate

HRID 486695Notes

Reaction equation

HRID 486695 reaction equation
[CH2:1]1[CH2:11][C:9](=[O:10])[C:8]2[C:3](=[CH:4][CH:5]=[CH:6][CH:7]=2)[CH2:2]1.[H-].[Na+].[C:14](=O)([O:18]CC)[O:15][CH2:16][CH3:17].Cl>O>[O:10]=[C:9]1[C:8]2[C:3](=[CH:4][CH:5]=[CH:6][CH:7]=2)[CH2:2][CH2:1][CH:11]1[C:14]([O:15][CH2:16][CH3:17])=[O:18]

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 7766Diethyl CarbonateHCID 107241-TetraloneHCID 24758Sodium hydride

Product 1

HCID 251472ethyl 1-oxo-1,2,3,4-tetrahydronaphthalene-2-carboxylateYield 57.6%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A suspension of 10 g (0.0684 mole) of α-tetralone, 3.56 g (0.0890 mole) of 60% sodium hydride and 32 g (0.2709 mole) of diethyl carbonate was heated under reflux for 1 hour, then poured into water, adjusted with conc. hydrochloric acid to a pH of 1 to 2, and extracted with ether. The ether layer was washed with water and then dried over magnesium sulfate. After evaporation of the solvent, the crude product was purified by silica gel column chromatography (hexane/ethyl acetate =9/1) to obtain 8.6 g of ethyl 1,2,3,4-tetrahydro-l-oxo-2-naphthalenecarboxylate, which was dissolved in tetrahydrofuran (220 ml) and then 1.90 g (0.0475 mole) of 60% sodium hydroxide was added under ice-cooling. After stirring for 30 minutes, 10.0 g (0.0599 mole) of ethyl bromoacetate was added, followed by stirring for 3 hours at room temperature. The reaction mixture was poured into ice-water, extracted with ether, and then the extract was subjected to washing with water, drying and solvent evaporation in a conventional manner. The crude product obtained was purified by silica gel column chromatography (hexane/ethyl acetate=5/1) to obtain 9.03 g of the following ethyl 2-ethoxycarbonyl-1,2,3,4-tetrahydro-1-oxo-2-naphthaleneacetate ##STR13##

Workup

  1. temperaturewas heated
  2. temperatureunder reflux for 1 hour
  3. extractionextracted with ether
  4. washThe ether layer was washed with water
  5. dry with materialdried over magnesium sulfate
  6. customAfter evaporation of the solvent
  7. customthe crude product was purified by silica gel column chromatography (hexane/ethyl acetate =9/1)

Sources & evidence

ORD record
ord-645ce88c68474f07b930734dfeb82cb1
Source dataset
uspto-grants-1994_03
Patent number
US05292768

Reaction notes

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