Methyl iodide → 1,4-Dimethoxy-2,3,5-trimethyl-benzene

HRID 2113993Notes

Reaction equation

[CH3:1][C:2]1[C:7]([CH3:8])=[C:6](O)[C:5]([CH3:10])=[CH:4][C:3]=1[OH:11].[C:12](=[O:15])([O-])[O-].[K+].[K+].[CH3:18]I>CCC(C)=O>[CH3:18][O:11][C:3]1[CH:4]=[C:5]([CH3:10])[C:6]([O:15][CH3:12])=[C:7]([CH3:8])[C:2]=1[CH3:1]

Participants

Conditions

Temperature: 65 °C

Procedure

A 2 L 3-N flask was charged with 2,3,5-trimethyl-benzene-1,4-diol (201; 50 g, 0.33 mol) and MEK (750 mL) to yield an amber solution. Potassium carbonate (210 g, 1.64 mol) was charged to the solution. After 30 min at room temperature, MeI (81.2 mL, 1.31 mol) was added to the brown suspension. The reaction mixture was heated to 65° C. for 72 h. After cooling to room temperature, the reaction mixture was concentrated to dryness by rotary evaporation to give a white paste. The paste was washed with EtOAc (3×300 mL). The EtOAc extracts were combined and concentrated by rotary evaporation. The resulting yellow-brown oil was chromatographed (80:20/heptanes:EtOAc) to yield 1,4-dimethoxy-2,3,5-trimethyl-benzene (47.2 g, 80%). 1H NMR (400 MHz; CDCl3; ppm): 6.55 (s, 1H), 3.80 (s, 3H), 3.68 (s, 3H), 2.30 (s, 3H), 2.22 (s, 3H), 2.14 (s, 3H).

Workup

customto yield an amber solution
temperatureAfter cooling to room temperature
concentrationthe reaction mixture was concentrated to dryness by rotary evaporation
customto give a white paste
washThe paste was washed with EtOAc (3×300 mL)
concentrationconcentrated by rotary evaporation
customThe resulting yellow-brown oil was chromatographed (80:20/heptanes:EtOAc)

Sources & evidence

ORD record: ord-8f3f7d8c70884e9e9f9d98e0fc9d997c
Source dataset: uspto-grants-2008_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07432305B2

Reaction notes

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