Trimethylhydroquinone → 6-Hydroxy-4,4,5,7,8-pentamethyl-3,4-dihydrocoumarin

HRID 921504Notes

Reaction equation

[CH3:1][C:2]1[C:8]([CH3:9])=[C:7]([OH:10])[C:6]([CH3:11])=[CH:5][C:3]=1[OH:4]>CS(O)(=O)=O>[OH:10][C:7]1[C:6]([CH3:11])=[C:5]2[C:3](=[C:2]([CH3:1])[C:8]=1[CH3:9])[O:4][C:3](=[O:4])[CH2:2][C:8]2([CH3:9])[CH3:7]

Participants

Conditions

Temperature: 70 °C

Procedure

A mixture of 2,3,5-trimethyl hydroquinone (10 g, 0.0657 mol) and methyl 1,1-dimethylacrylate (7.5 g, 0.0657) in 50 ml of methanesulfonic acid was heated to 70° C. for 2 hours. Upon cooling to room temperature, the mixture was poured into 100 ml of ice-cold water. The resulting mixture was extracted three times with ethyl acetate, and the combined organic layers were washed with water and dried over sodium sulfate. After removal of the majority of ethyl acetate, the mixture was cooled −20° C. The pale white solid was collected by filtration, washed with cold ethyl acetate and dried under vacuum oven. The yield was 75%. 1H NMR (300 MHz, CD2Cl2) δ ppm: 4.69 (s, 1H, OH), 2.59 (s, 2H, CH2), 2.53 (s, 3H, CH3), 2.35 (s, 3H, CH3), 2.20 (s, 3H, CH3), 1.57 (s, 3H, CH3), 1.44 (s, 3H, CH3); MS (m/e): 235 (M+).

Workup

temperatureUpon cooling to room temperature
extractionThe resulting mixture was extracted three times with ethyl acetate
washthe combined organic layers were washed with water
dry with materialdried over sodium sulfate
customAfter removal of the majority of ethyl acetate
temperaturethe mixture was cooled −20° C
filtrationThe pale white solid was collected by filtration
washwashed with cold ethyl acetate
customdried under vacuum oven

Sources & evidence

ORD record: ord-c366c39f455b4474ba0797357a888149
Source dataset: uspto-grants-2016_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09273343B2

Reaction notes

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