Hydrochloric Acid → Methyl 8-oxo-5,6,7,8-tetrahydronaphthalene-2-carboxylate

HRID 1682515Notes

Reaction equation

HRID 1682515 reaction equation
[C:1]1(=[O:14])[C:10]2[C:5](=[CH:6][CH:7]=[C:8]([C:11]([OH:13])=[O:12])[CH:9]=2)[CH2:4][CH2:3][CH2:2]1.[CH3:15]O.Cl>>[CH3:15][O:12][C:11]([C:8]1[CH:9]=[C:10]2[C:5]([CH2:4][CH2:3][CH2:2][C:1]2=[O:14])=[CH:6][CH:7]=1)=[O:13]

Participants

4

Reactant 3

HCID 313Hydrochloric AcidHCID 887MethanolHCID 147565478-Oxo-5,6,7,8-tetrahydronaphthalene-2-carboxylic acid

Product 1

HCID 10987358Methyl 8-oxo-5,6,7,8-tetrahydronaphthalene-2-carboxylateYield 49%

Procedure

Part A--A mixture of 1-tetralon-7-carboxylic acid (7.0 g, 0.037 mol) in methanol (13.6 mL, 10.8 g, 0.30 mol) with a catalytic amount of hydrochloric acid (0.07 mL, 0.12 g, 0.0012 mol) was stirred at reflux over 5 hours. The cooled reaction mixture was poured into ice water and extracted with ethyl acetate. The combined organic layers were backwashed with water and brine, dried over anhydrous magnesium sulfate and evaporated to dryness under reduced pressure. The resulting solid was purified by flash chromatography using hexane:ethyl acetate::75:25. The resulting solid was triturated with hexane to give 1-tetralon-7-carboxylic acid methyl ester (3.61 g, 0.018 mol, 49%) as a yellow solid. mp=170°-172° C.; 1H NMR (CDCl3) d 8.7 (s, 1H), 8.15 (d, 1H, J=8.1 Hz), 7.35 (d, 1H, J=8.1 Hz), 3.95 (s, 3H), 3.05 (d, 2H, J=6.1 Hz), 2.7 (t, 2H, J=6.4 Hz), 2.15 (quintet, 2H, J=6.2 Hz).

Workup

  1. temperatureat reflux over 5 hours
  2. customThe cooled reaction mixture
  3. extractionextracted with ethyl acetate
  4. dry with materialdried over anhydrous magnesium sulfate
  5. customevaporated to dryness under reduced pressure
  6. customThe resulting solid was purified by flash chromatography
  7. customThe resulting solid was triturated with hexane

Sources & evidence

ORD record
ord-d9cb39208a8444cd902fc7de5bd00cc6
Source dataset
uspto-grants-1997_06
Patent number
US05635477

Reaction notes

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