2-Bromo-4-methoxyphenol → diethyl (2Z)-2-(2-bromo-4-methoxyphenoxy)-2-butenedioate

HRID 2414480Notes

Reaction equation

HRID 2414480 reaction equation
[C:1]([C:6]([O:8][CH2:9][CH3:10])=[O:7])#[C:2][C:3]([O-:5])=[O:4].[Br:11][C:12]1[CH:17]=[C:16]([O:18][CH3:19])[CH:15]=[CH:14][C:13]=1[OH:20].[F-].[CH2:22]([N+](CCCC)(CCCC)CCCC)[CH2:23]CC>CC(O)C>[Br:11][C:12]1[CH:17]=[C:16]([O:18][CH3:19])[CH:15]=[CH:14][C:13]=1[O:20]/[C:1](=[CH:2]\[C:3]([O:5][CH2:22][CH3:23])=[O:4])/[C:6]([O:8][CH2:9][CH3:10])=[O:7]

Participants

5

Reactant 3

HCID 2973822-Bromo-4-methoxyphenolHCID 2724141Tetrabutylammonium FluorideHCID 713605752-Butynedioic acid, monoethyl ester

Product 1

HCID 86587184diethyl (2Z)-2-(2-bromo-4-methoxyphenoxy)-2-butenedioateYield 62%

Reagents, catalysts & solvents 1

HCID 3776IsopropanolSolvent

Procedure

Ethyl acetylenedicarboxylate (17.8 ml, 0.145 mol) was added to 2-bromo-4-methoxyphenol (Synlett p 1241, 1997) (27.3 g, 0.134 mol), in anhydrous 2-propanol (55 ml) followed by the addition of a catalytic amount of tetrabutylammonium fluoride (0.4 ml, 1.0 M in THF). The solution was stirred at room temperature overnight and was then heated to reflux for 30 min. Upon cooling a precipitate formed. The solution was cooled and filtered to give diethyl (2Z)-2-(2-bromo-4-methoxyphenoxy)-2-butenedioate as a yellow solid (29.9 g, 62% yield). Note: the solid contains 10% of diethyl (2E)-2-(2-bromo-4-methoxyphenoxy)-2-butenedioate. GC/MS (EI, M+) m/z 344 and 346.

Workup

  1. temperaturewas then heated
  2. temperatureto reflux for 30 min
  3. temperatureUpon cooling a precipitate
  4. customformed
  5. temperatureThe solution was cooled
  6. filtrationfiltered

Sources & evidence

ORD record
ord-3aeb41fa93b6451eaf4caed22d50c1bc
Source dataset
uspto-grants-2004_11
Patent number
US06812225B2

Reaction notes

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