Ethanol → 1,4-Dimethoxy-2,3,5-trimethyl-benzene

HRID 1021195Notes

Reaction equation

[CH3:1][C:2]1[C:8]([CH3:9])=[C:7](O)[C:6]([CH3:11])=[CH:5][C:3]=1[OH:4].COS([O:17][CH3:18])(=O)=O.[OH-].[Na+].[NH4+].[OH-].[CH3:23]CO>O.C(OC(C)C)(=O)C>[CH3:23][O:4][C:3]1[CH:5]=[C:6]([CH3:11])[C:7]([O:17][CH3:18])=[C:8]([CH3:9])[C:2]=1[CH3:1]

Participants

Conditions

Temperature: 40 °C

Procedure

2,3,5-Trimethylhydroquinone (50.2 g) in 400 mL EtOH was treated with a solution of 10 g Na2S2O3.5H2O in 50 mL H2O followed by Me2SO4 (68 mL, 2.2 equiv.). To this was added slowly 10 M NaOH (100 mL, 3.0 equiv.) via dropping funnel until the reaction temperature reached 60° C. (65 mL added). The remaining 35 mL NaOH solution was added slowly, dropwise over 1 h to maintain a minimum 40° C. reaction temperature. After 2.0 h, the reaction vessel had returned to ambient temperature and an additional portion of Me2SO4 (10 mL, 13.3 g,) was added causing a slight rise in temperature. After 1 h, the reaction had returned to room temperature, 100 mL conc. NH4OH was added and let stir overnight. The red-brown solution was diluted with isopropyl acetate, the organics washed with 200 mL H2O, 200 mL 1.0 M NaHCO3 and 2×200 mL saturated aqueous NaCl, dried over MgSO4 and concentrated to give 61.2 g of 1,4-dimethoxy-2,3,5-trimethylbenzene as a brown oil. 1H NMR (400 MHz, CDCl3) δ=6.53 (s, 1 H), 3.78 (s, 3 H), 3.66 (S, 3 H), 2.28 (s, 3 H), 2.20 (s, 3 H), 2.12 (s, 3 H) ppm.

Workup

customreached 60° C.
addition(65 mL added)
customreaction temperature
customhad returned to ambient temperature
waitAfter 1 h
customhad returned to room temperature
washthe organics washed with 200 mL H2O, 200 mL 1.0 M NaHCO3 and 2×200 mL saturated aqueous NaCl
dry with materialdried over MgSO4
concentrationconcentrated

Sources & evidence

ORD record: ord-94aefc166baf4091a4f77629cee2df62
Source dataset: uspto-grants-2014_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08716527B2

Reaction notes

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