Iodoethane → (E)-2-ethyl-1,3-diMethoxy-5-styrylbenzene

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Reaction Conditions

Reaction Steps

3,5-Dimethoxy-4-ethyl-trans-stilbene (compound 15A-a in Scheme 5): t-butyl Li (1.1 mL, 1M in THF) was added at −78° C. to a THF solution (10 mL) containing 3,5-dimethoxy-4-bromo-trans-stilbene (0.53 g). After addition, the solution was slowly heated to reflux for 30 min and then cooled down to −78° C. Ethyl iodide (1.2 eq, 0.265 mL) was added to the solution at −78° C. After reaction finished, water (10 mL) was added dropwise to the mixture, THF was evaporated under reduced pressure. The mixture was extracted with CH2Cl2 (5 mL×3), the combined organic layer was dried over anhydrous magnesium sulfate, and remove under reduced pressure. The product mixture was purified by column chromatography (ether/pet ether=1:8) and gave 3,5-dimethoxy-4-ethyl-trans-stilbene (15A-a) (70%) and 3,5-dimethoxy-trans-stilbene (30%) due to the moisture. Mp: 70-73° C. NMR (400 MHz, CDCl3): δ 1.12 (t, 6H, J=7.2 Hz, CH3), 2.70 (q, 2H, —CH2—), 3.91 (s, 6H, OCH3), 6.74 (s, 2H, H-2, 6), 7.07 (s, 2H), 7.26 (m, 1H, H-4′), 7.36 (m, 2H, H-3′, 5′), 7.52 (m, 2H, H-2′, 6′).

Provenance & Evidence