Lithium Hexamethyldisilazide → 1-(3,4-Dimethoxyphenyl)-1-(3-ethoxy-4-methoxyphenyl)prop-1-ene

HRID 583443

Reaction equation

HRID 583443 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]([C:11]([C:17]2[CH:22]=[CH:21][C:20]([O:23][CH3:24])=[C:19]([O:25][CH3:26])[CH:18]=2)=[CH:12][C:13](OC)=O)[CH:6]=[CH:7][C:8]=1[O:9][CH3:10].[CH3:27]OC1C=C(C=CC=1OC)C(C1C=CC(OC)=C(OCC)C=1)=O.C[Si](C)(C)[N-][Si](C)(C)C.[Li+]>[Br-].C([P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)C>[CH3:26][O:25][C:19]1[CH:18]=[C:17]([C:11]([C:5]2[CH:6]=[CH:7][C:8]([O:9][CH3:10])=[C:3]([O:2][CH2:1][CH3:27])[CH:4]=2)=[CH:12][CH3:13])[CH:22]=[CH:21][C:20]=1[O:23][CH3:24]

Participants

5

Reactant 3

HCID 2733832Lithium HexamethyldisilazideHCID 9820154Methyl 3,3-bis-(3,4-dimethoxyphenyl)acrylateHCID 222259763,4-Dimethoxy-3'-ethoxy-4'-methoxybenzophenone

Product 1

HCID 544274051-(3,4-Dimethoxyphenyl)-1-(3-ethoxy-4-methoxyphenyl)prop-1-ene

Reagents, catalysts & solvents 1

HCID 73727Phosphonium, ethyltriphenyl-, bromide (1:1)Catalyst

Procedure

1-(3,4-Dimethoxyphenyl)-1-(3-ethoxy-4-methoxyphenyl)prop-1-ene was prepared analogously to methyl 3,3-bis-(3,4-dimethoxyphenyl)acrylate using 3,4-dimethoxy-3'-ethoxy-4'-methoxybenzophenone (1.6 g, 5 mmol), (ethyl)triphenylphosphonium bromide (2.04 g, 5.5 mmol) and lithium hexamethyldisilazide (4.2 mL, 5.5 mmol, 1.3M) with a reaction time of 24 hours at room temperature. The crude mixture was purified by flash column chromatography (silica gel, 10% hexane/methylene chloride) to afford 0.8 g (49%) of a mixture of the E and Z isomers as a white solid: mp 65.5-68° C.; 1H NMR (CDCl3) δ 6.95-6.65 (m, 12H), 6.14-6.00 (m, 2H), 4.11-3.78 (m, 22H), 1.86-1.74 (m, 6 H), 1.50-1.36 (m, 6H); 13C NMR (CDCl3) δ 148.5, 148.4, 148.1, 147.7, 141.8, 141.7, 136.1, 136.0, 132.6, 132.5, 122.5, 122.3, 119.7, 114.7, 113.1, 111.9, 111.0, 110.7, 110.4, 55.9, 55.8, 55.8, 55.7, 15.7, 14.7; Anal. Calcd for C20H24O4. Theoretical: C, 73.15; H, 7.37. Found: C, 73.33; H, 7.39.

Workup

  1. customwith a reaction time of 24 hours
  2. customat room temperature
  3. customThe crude mixture was purified by flash column chromatography (silica gel, 10% hexane/methylene chloride)

Sources & evidence

ORD record
ord-ccd3fbce04ad4a7ba786881cbc933222
Source dataset
uspto-grants-1999_07
Patent number
US05929117

Linked notes

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