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
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
- customThe ice bath was removed
- additionThe reaction mixture was diluted with EtOAc
- washwashed sequentially with NaHCO3 (2×20 mL) and brine (2×20 mL) solutions
- customThe organic layer was separated
- dry with materialdried over Na2SO4
- filtrationfiltered
- customthe solvent was evaporated under reduced pressure
- customThe crude product was purified with silica gel using (0-30%) ethyl acetate-hexanes
Sources & evidence
- ORD record
- ord-5d033869e9ff42b489a208698f25705b
- Source dataset
- uspto-grants-2014_09
- Patent number
- US08828996B2
Linked notes
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