Diethyl Carbonate → Ethyl 7-methoxy-1-oxo-3,4-dihydro-2H-naphthalene-2-carboxylate

HRID 654234Notes

Reaction equation

HRID 654234 reaction equation
COC1C=C2C(CCC(C(O)=O)C2)=CC=1.[CH3:16][O:17][C:18]1[CH:27]=[C:26]2[C:21]([CH2:22][CH2:23][CH2:24][C:25]2=[O:28])=[CH:20][CH:19]=1.[CH2:29]([O:31][C:32](=O)[O:33]CC)[CH3:30].[H-].[Na+]>O1CCCC1.O.C(O)(=O)C>[CH2:29]([O:31][C:32]([CH:24]1[CH2:23][CH2:22][C:21]2[C:26](=[CH:27][C:18]([O:17][CH3:16])=[CH:19][CH:20]=2)[C:25]1=[O:28])=[O:33])[CH3:30]

Participants

8

Reactant 4

HCID 7766Diethyl CarbonateHCID 24758Sodium hydrideHCID 812767-Methoxy-1,2,3,4-tetrahydronaphthalen-1-oneHCID 147228197-Methoxy-1,2,3,4-tetrahydronaphthalene-2-carboxylic acid

Product 1

HCID 10848142Ethyl 7-methoxy-1-oxo-3,4-dihydro-2H-naphthalene-2-carboxylateYield 96.4%

Reagents, catalysts & solvents 3

HCID 176Acetic AcidSolventHCID 962WaterSolventHCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
60 °C

Procedure

The starting 7-methoxy-1,2,3,4-tetrahydronaphthalen-2-carboxylic acid, which is a known product, can be prepared as follows: a solution of 7-methoxy-3,4-dihydronaphthalene-1(2H)-one (66.4 g, 0.376 mol) in anhydrous tetrahydrofuran (350 ml) is added in 1 hour to a mixture of distilled diethylcarbonate (116 ml, 0.957 mol), 80% sodium hydride (39.7 g, 1.32 mol) and anhydrous tetrahydrofuran (350 ml) heated to 60° C. The thus obtained reaction mixture is refluxed for 4 hours and then cooled. Acetic acid is then added dropwise up to acidic pH and water is added until complete dissolution of the precipitate occurs. The solution is extracted with ethyl ether, the organic phase is washed with water and with a sodium bicarbonate solution, dried and evaporated to dryness. The thus obtained oily product is purified by distillation under reduced pressure yielding 90 g of 7-methoxy-1-oxo-1,2,3,4-tetrahydronaphthalen-2-carboxylic acid ethyl ester. B.p.0.4 mmHg 160°-165° C.

Workup

  1. customcan be prepared
  2. customThe thus obtained reaction mixture
  3. temperatureis refluxed for 4 hours
  4. temperaturecooled
  5. additionis added until complete dissolution of the precipitate
  6. extractionThe solution is extracted with ethyl ether
  7. washthe organic phase is washed with water and with a sodium bicarbonate solution
  8. customdried
  9. customevaporated to dryness
  10. distillationThe thus obtained oily product is purified by distillation under reduced pressure

Sources & evidence

ORD record
ord-b7b217498f464c609302d6871c45166e
Source dataset
uspto-grants-1992_07
Patent number
US05130339

Reaction notes

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