Methallyl alcohol → Methyl 3-methoxy-4-(2-methylallyloxy)benzoate

HRID 713012Notes

Reaction equation

HRID 713012 reaction equation
[OH:1][C:2]1[CH:11]=[CH:10][C:5]([C:6]([O:8][CH3:9])=[O:7])=[CH:4][C:3]=1[O:12][CH3:13].[CH3:14][C:15](=[CH2:18])[CH2:16]O.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.CC(OC(/N=N/C(OC(C)C)=O)=O)C>C1COCC1>[CH3:13][O:12][C:3]1[CH:4]=[C:5]([CH:10]=[CH:11][C:2]=1[O:1][CH2:16][C:15]([CH3:18])=[CH2:14])[C:6]([O:8][CH3:9])=[O:7]

Participants

6

Reactant 4

HCID 10557Methallyl alcoholHCID 11776TriphenylphosphineHCID 19844Methyl VanillateHCID 5363146Diisopropyl azodicarboxylate

Product 1

HCID 51109732Methyl 3-methoxy-4-(2-methylallyloxy)benzoateYield 75%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
55 °C

Procedure

To a stirred solution of methyl 4-hydroxy-3-methoxy-benzoate (2 g, 10.98 mmol), 2-methylprop-2-en-1-ol (871.0 mg, 1.0 mL, 12.1 mmol) and triphenylphosphine (3.17 g, 2.8 mL, 12.1 mmol) in THF (63.28 mL) at 0° C. was added DIAD (2.44 g, 2.34 mL, 12.1 mmol). The ice bath was removed and the reaction was stirred at 55° C. for 16 hours. The reaction mixture was diluted with EtOAc and washed sequentially with NaHCO3 (2×20 mL) and brine (2×20 mL) solutions. The organic layer was separated, dried over Na2SO4, filtered and the solvent was evaporated under reduced pressure. The crude product was purified with silica gel using (0-30%) ethyl acetate-hexanes to yield methyl 3-methoxy-4-(2-methylallyloxy)benzoate (1.94 g, 75%) as a viscous liquid. ESI-MS m/z calc. 236.1. found 237.1 (M+1)+. Retention time: 1.63 minutes (3 min run). 1H NMR (400 MHz, DMSO) δ 7.56 (dd, J=8.4, 2.0 Hz, 1H), 7.47 (d, J=1.9 Hz, 1H), 7.06 (d, J=8.5 Hz, 1H), 5.07 (br s, 1H), 4.97 (br s, 1H), 4.55 (s, 2H), 3.83 (s, 3H), 3.82 (s, 3H), 1.78 (s, 3H).

Workup

  1. customThe ice bath was removed
  2. additionThe reaction mixture was diluted with EtOAc
  3. washwashed sequentially with NaHCO3 (2×20 mL) and brine (2×20 mL) solutions
  4. customThe organic layer was separated
  5. dry with materialdried over Na2SO4
  6. filtrationfiltered
  7. customthe solvent was evaporated under reduced pressure
  8. customThe crude product was purified with silica gel using (0-30%) ethyl acetate-hexanes

Sources & evidence

ORD record
ord-c093d85e7e624280bc01516dc9b26e49
Source dataset
uspto-grants-2015_11
Patent number
US09181273B2

Reaction notes

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