Hydrochloric Acid → Ethyl 4-Hydroxy-4-[3,4-dimethoxy-2-(1-methylethyl)phenyl]-3-methylbut-2-enoate

HRID 1585264Notes

Reaction equation

HRID 1585264 reaction equation
Br[C:2]1[CH:7]=[CH:6][C:5]([O:8][CH3:9])=[C:4]([O:10][CH3:11])[C:3]=1[CH:12]([CH3:14])[CH3:13].C(Br)C.[Mg].[CH3:19][C:20]([CH:27]=[O:28])=[CH:21][C:22]([O:24][CH2:25][CH3:26])=[O:23].Cl>C1COCC1>[OH:28][CH:27]([C:2]1[CH:7]=[CH:6][C:5]([O:8][CH3:9])=[C:4]([O:10][CH3:11])[C:3]=1[CH:12]([CH3:14])[CH3:13])[C:20]([CH3:19])=[CH:21][C:22]([O:24][CH2:25][CH3:26])=[O:23]

Participants

7

Reactant 5

HCID 313Hydrochloric AcidHCID 6332Ethyl BromideHCID 3016304Ethyl 3-methyl-4-oxocrotonateHCID 5462224MagnesiumHCID 143124351-Bromo-3,4-dimethoxy-2-(propan-2-yl)benzene

Product 1

HCID 67591228Ethyl 4-Hydroxy-4-[3,4-dimethoxy-2-(1-methylethyl)phenyl]-3-methylbut-2-enoateYield 79%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
0 °C

Procedure

Compound 7 (10.0 g, 38.6 mmol) and ethyl bromide (0.60 g, 5.5mmol) were added to magnesium turnings (1.20 g, 49.4 mg atom) in 100 mL of dry THF in a 520 mL round bottom flask equipped with a reflux condenser and magnetic stirrer. The mixture was refluxed with stirring under a static nitrogen atmosphere for 1 h. The reaction mixture was cooled to 0° C. and 7a (6.90 g, 48.5mmol) in 25 mL of dry THF at 0° C. was added. The mixture was stirred at ambient temp for 1 h and poured into 100 g of ice and 25 ml of 6M HCl. The organic layer was extracted into ether and the ether was washed with water and brine and dried over MgSO4. The ether was evaporated and the byproducts distilled bulb to bulb (120° C./1 torr) to leave 9.8 g (30.4 mmol, 79%) of 8 as a residual oil: IR 3440 (alcohol), 1722 (ester), 1655 (alkene) cm-1 ; 1H NMR δ1.31 (t, J=7.1 Hz, 3H), 1.37 (d, J=7.0 Hz, 6H), 1.99 (s, 3H), 3.40 (br s, 1H), 3.75-3.85 (m, 1H), 3.847 (s, 3H), 3.853 (s, 3H), 4.19 (q, J+7.1 Hz, 2H), 5.39 (s, 1H), 6.26 (s, 1H), 6.75 (d, J=8.6 Hz, 1H), 6.94 (d, J=7.1 Hz, 1H). Anal. (C18H26O5) C,H.

Workup

  1. customequipped with a reflux condenser and magnetic stirrer
  2. temperatureThe mixture was refluxed
  3. stirringThe mixture was stirred at ambient temp for 1 h
  4. extractionThe organic layer was extracted into ether
  5. washthe ether was washed with water and brine
  6. dry with materialdried over MgSO4
  7. customThe ether was evaporated
  8. distillationthe byproducts distilled bulb to bulb (120° C./1 torr)

Sources & evidence

ORD record
ord-cab01c5d8644400798d6d65457420431
Source dataset
uspto-grants-1999_08
Patent number
US05936120

Reaction notes

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