Bromocyclopentane → 6-Cyclopentyl-1,5-dimethoxy-cyclohexa-1,4-diene

Temperature

-20 °C

To a solution of 2,5-dihydro-1,3-dimethoxybenzene (9.88 g, 70 mmol) in dry THF (150 mL) was added dropwise nBuLi solution (2.5 M, 42.4 mL) in hexane at −20° C. The orange colored reaction mixture was stirred for 0.5 hour at −20° C., then cyclopentyl bromide (20.9 g, 140 mmol) was added dropwise. The reaction mixture was stirred for 1 hour at −20° C. to 0° C. Excess nBuLi was destroyed cautiously with methanol. To the reaction mixture, 140 mL of cold water was added. The product was extracted with ethyl acetate (3×80 mL). The combined organic extract was washed with brine, dried over anhydrous sodium sulfate, and concentrated to give the title compound as light yellow liquid (14.12 g, 96.8%). 1H NMR: δ 1.0–2.4 (Complex, 9H), 2.7–2.94 (m, 3H), 3.52 (s, 6H, 2×OCH3), 4.70 (t, 2H).

1. stirringThe reaction mixture was stirred for 1 hour at −20° C. to 0° C
2. customExcess nBuLi was destroyed cautiously with methanol
3. additionTo the reaction mixture, 140 mL of cold water was added
4. extractionThe product was extracted with ethyl acetate (3×80 mL)
5. extractionThe combined organic extract
6. washwas washed with brine
7. dry with materialdried over anhydrous sodium sulfate
8. concentrationconcentrated

ORD record

ord-08b03307411e46cd9803a66086163d32

Source dataset

uspto-grants-2006_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06982260B1