Isopropyl iodide → 6-Isopropyl-1,5-dimethoxy-cyclohexa-1,4-diene

Temperature

-20 °C

To a solution of 1,5-dimethoxy-cyclohexa-1,4diene (7 g, 50 mmol) in dry THF (140 mL) was added dropwise nBuLi solution (2.5 M, 30 mL) in hexane at −20° C. The orange colored reaction mixture was stirred for 0.5 hours at −20° C., then isopropyl iodide (17 g, 100 mmol) was added dropwise. The reaction mixture was stirred for 1 hour, while the temperature was raised to 0° C. Excess nBuLi was destroyed cautiously with methanol. Cold water (140 mL) was added to the reaction mixtures, then the product was extracted with ethyl acetate (3×70 mL). The combined organic extracts were washed with brine, dried over anhydrous sodium sulfate, and concentrated to give the title compound as a light yellow liquid (8.5 g, 93.4%). 1H NMR CDCl3): δ 0.90 (d, 6H, 2×CH3), 2.1 (m, 1H, CH), 2.76 (m, 3H, CH2 and CH), 3.53 (s, 6H, 2×OCH3), 4.73 (t, 2H, olefinic).

1. stirringThe reaction mixture was stirred for 1 hour, while the temperature
2. temperaturewas raised to 0° C
3. customExcess nBuLi was destroyed cautiously with methanol
4. additionCold water (140 mL) was added to the reaction mixtures
5. extractionthe product was extracted with ethyl acetate (3×70 mL)
6. washThe combined organic extracts were washed with brine
7. dry with materialdried over anhydrous sodium sulfate
8. concentrationconcentrated

ORD record

ord-7a13bf5cea60430e82028c099c5d5187

Source dataset

uspto-grants-2006_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06982260B1