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

HRID 2252337Notes

Reaction equation

HRID 2252337 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5](/[CH:13]=[CH:14]/[C:15]2[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=2)[CH:6]=[C:7]([O:11][CH3:12])[C:8]=1[CH2:9][CH3:10].[CH3:21][O:22][C:23]1[CH:24]=[C:25](/[CH:32]=[CH:33]/[C:34]2[CH:39]=[CH:38][CH:37]=[CH:36][CH:35]=2)[CH:26]=[C:27]([O:30][CH3:31])[C:28]=1Br.C(I)C>C1COCC1.O>[CH3:12][O:11][C:7]1[CH:6]=[C:5](/[CH:13]=[CH:14]/[C:15]2[CH:16]=[CH:17][CH:18]=[CH:19][CH:20]=2)[CH:4]=[C:3]([O:2][CH3:1])[C:8]=1[CH2:9][CH3:10].[CH3:31][O:30][C:27]1[CH:26]=[C:25](/[CH:32]=[CH:33]/[C:34]2[CH:39]=[CH:38][CH:37]=[CH:36][CH:35]=2)[CH:24]=[C:23]([O:22][CH3:21])[CH:28]=1

Participants

7

Reactant 3

HCID 6340IodoethaneHCID 10018825HCID 10018825, compoundHCID 10468248(E)-2-ethyl-1,3-diMethoxy-5-styrylbenzene2×

Product 2

HCID 5316874Pinosylvin, dimethyl etherYield 30%HCID 10468248(E)-2-ethyl-1,3-diMethoxy-5-styrylbenzeneYield 70%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
-78 °C

Procedure

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′).

Workup

  1. additionAfter addition
  2. temperaturethe solution was slowly heated
  3. temperatureto reflux for 30 min
  4. customAfter reaction
  5. customwas evaporated under reduced pressure
  6. extractionThe mixture was extracted with CH2Cl2 (5 mL×3)
  7. dry with materialthe combined organic layer was dried over anhydrous magnesium sulfate
  8. customremove under reduced pressure
  9. customThe product mixture was purified by column chromatography (ether/pet ether=1:8)

Sources & evidence

ORD record
ord-5fe85bb59ec7429191f252dbe914db3f
Source dataset
uspto-grants-2008_01
Patent number
US07321050B2

Reaction notes

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