Toluene → 4,4'-Tolan-dicarboxylic acid di-tert.-butyl ester

HRID 974210Notes

Reaction equation

HRID 974210 reaction equation
[C:1]([O:5][C:6](=[O:14])[C:7]1[CH:12]=[CH:11][C:10](Br)=[CH:9][CH:8]=1)([CH3:4])([CH3:3])[CH3:2].[CH3:15][C:16]([OH:20])([C:18]#C)[CH3:17].C1(P([C:34]2[CH:39]=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.[OH-:40].[Na+].[C:42]1([CH3:48])[CH:47]=[CH:46][CH:45]=[CH:44][CH:43]=1>[Cl-].C([N+](CC)(CC)CC)C1C=CC=CC=1.[Cu]I>[C:16]([O:20][C:48]([C:42]1[CH:47]=[CH:46][C:45]([C:39]#[C:34][C:10]2[CH:11]=[CH:12][C:7]([C:6]([O:5][C:1]([CH3:4])([CH3:3])[CH3:2])=[O:14])=[CH:8][CH:9]=2)=[CH:44][CH:43]=1)=[O:40])([CH3:18])([CH3:17])[CH3:15]

Participants

8

Reactant 5

HCID 1140TolueneHCID 82582-Methyl-3-butyn-2-olHCID 11776TriphenylphosphineHCID 14798Sodium HydroxideHCID 11334366Tert-butyl 4-bromobenzoate

Product 1

HCID 148475264,4'-Tolan-dicarboxylic acid di-tert.-butyl ester

Reagents, catalysts & solvents 2

HCID 24350Copper(1+) iodide; Copper(I) iodide; Cuprous iodide; Cuprous iodide (CuI)CatalystHCID 66133Benzyl triethylammonium chlorideCatalyst

Procedure

A mixture of 514 g of 4-bromobenzoic acid tert.-butyl ester, 88.25 g of 2-methyl-3-butyn-2-ol and 74.5 g of triphenylphosphine in 1250 ml of toluene is added to 7.1 g of benzyl triethylammonium chloride, 9.55 g of copper(I)iodide and 14 g of (Pφ3)2PdCl2 and the reaction mixture is stirred at reflux for 48 hours after the addition of 750 ml of 5.5 N NaOH. The organic phase is separated off, dried and concentrated by evaporation. 430 g of moist crude product are stirred up in 550 ml of methanol and suction filtered. 248 g of 4,4'-tolan-dicarboxylic acid di-tert.-butyl ester are obtained and may be further purified by recrystallisation from acetonitrile.

Workup

  1. temperatureat reflux for 48 hours
  2. customThe organic phase is separated off
  3. customdried
  4. concentrationconcentrated by evaporation
  5. stirring430 g of moist crude product are stirred up in 550 ml of methanol
  6. filtrationsuction filtered

Sources & evidence

ORD record
ord-11b7ead8b8d24e0d8968afbee00b18a3
Source dataset
uspto-grants-1991_11
Patent number
US05068300

Reaction notes

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