1,2-Dibromoethane → Z-4,4'-Stilbene-dicarboxylic acid di-tert.-butyl ester

HRID 974211Notes

Reaction equation

HRID 974211 reaction equation
BrCCBr.[Li+].[Br-].[C:7]([O:11][C:12]([C:14]1[CH:19]=[CH:18][C:17]([C:20]#[C:21][C:22]2[CH:27]=[CH:26][C:25]([C:28]([O:30][C:31]([CH3:34])([CH3:33])[CH3:32])=[O:29])=[CH:24][CH:23]=2)=[CH:16][CH:15]=1)=[O:13])([CH3:10])([CH3:9])[CH3:8]>C1COCC1.C(O)C.[Zn]>[C:31]([O:30][C:28]([C:25]1[CH:26]=[CH:27][C:22](/[CH:21]=[CH:20]\[C:17]2[CH:16]=[CH:15][C:14]([C:12]([O:11][C:7]([CH3:10])([CH3:9])[CH3:8])=[O:13])=[CH:19][CH:18]=2)=[CH:23][CH:24]=1)=[O:29])([CH3:34])([CH3:33])[CH3:32]

Participants

7

Reactant 3

HCID 78391,2-DibromoethaneHCID 82050Lithium BromideHCID 148475264,4'-Tolan-dicarboxylic acid di-tert.-butyl ester

Product 1

HCID 67931836Z-4,4'-Stilbene-dicarboxylic acid di-tert.-butyl esterYield 92.1%

Reagents, catalysts & solvents 3

HCID 23994ZincCatalystHCID 702EthanolSolvent2×HCID 8028TetrahydrofuranSolvent2×

Procedure

52.6 g of Zn and 70 ml of ethanol are heated together with 13 g of 1,2-dibromoethane until evolution of gas ceases. A solution of 13 g of CuBr and 15.8 g of anhydrous LiBr in 70 ml of THF is added at 40° to 50° C. and the reaction mixture is stirred for 10 minutes. A hot solution of 50 g of 4,4'-tolan-dicarboxylic acid di-tert.-butyl ester in 70 ml of ethanol and 130 ml of THF is added and the mixture is heated under reflux for 72 hours. After filtration, the filtrate is concentrated by evaporation, taken up with CH2Cl2, washed twice with dilute HCl and H2O, dried and concentrated by evaporation. 46.3 g of Z-4,4'-stilbene dicarboxylic acid di-tert.-butyl ester are obtained.

Workup

  1. temperaturethe mixture is heated
  2. temperatureunder reflux for 72 hours
  3. filtrationAfter filtration
  4. concentrationthe filtrate is concentrated by evaporation
  5. washwashed twice with dilute HCl and H2O
  6. customdried
  7. concentrationconcentrated by evaporation

Sources & evidence

ORD record
ord-bbcd35964df84117b1013f16e3915ec0
Source dataset
uspto-grants-1991_11
Patent number
US05068300

Reaction notes

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