Dimethylformamide → 3-(2-Bromophenyl)-4-isopropoxycyclobut-3-ene-1,2-dione

HRID 1779435Notes

Reaction equation

HRID 1779435 reaction equation
[CH:1]([O:4][C:5]1[C:6](=[O:23])[C:7](=[O:22])[C:8]=1[Sn](CCCC)(CCCC)CCCC)([CH3:3])[CH3:2].[Br:24][C:25]1[CH:30]=[CH:29][CH:28]=[CH:27][C:26]=1I.CN(C)C=O>C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1.C(OCC)C>[Br:24][C:25]1[CH:30]=[CH:29][CH:28]=[CH:27][C:26]=1[C:8]1[C:7](=[O:22])[C:6](=[O:23])[C:5]=1[O:4][CH:1]([CH3:2])[CH3:3]

Participants

6

Reactant 3

HCID 6228DimethylformamideHCID 114151-Bromo-2-iodobenzeneHCID 27366833-Isopropoxy-4-(tri-n-butylstannyl)-3-cyclobutene-1,2-dione

Product 1

HCID 199555823-(2-Bromophenyl)-4-isopropoxycyclobut-3-ene-1,2-dione

Reagents, catalysts & solvents 2

HCID 178418397HCID 178418397, compoundCatalystHCID 3283Diethyl EtherSolvent

Procedure

A mixture of 3-isopropoxy-4-tributylstannyl-cyclobut-3-ene-1,2-dione (4.68 g; preparable as described in Liebeskind and Fengl, Journal of Organic Chemistry (1990), Vol.55, pp 5359/5364), 1-bromo-2-iodobenzene (3.54 g), dry dimethylformamide (15 ml), tetrakis(triphenylphosphine)palladium(0) (0.606 g) and cuprous iodide (0.196 g) was stirred under a nitrogen atmosphere at ambient temperature for approximately 2.5 hours then kept at ambient temperature for 3 days. Diethyl ether (225 ml) was added, and the mixture obtained was washed with saturated aqueous ammonium chloride (225 ml) and then with 10% aqueous potassium fluoride solution (3×225 ml). The organic phase was filtered through a silica bed (5 cm diameter×1 cm depth), and the collected solids were washed with diethyl ether (50 ml). The resulting orange filtrate and washings were combined and evaporated to give a semi-solid brown oil, which was purified by flash chromatography on silica gel (loading in dichloromethane and eluting with 20% diethyl ether in petroleum ether (b.p. 40°-60° C.)) to give the intermediate compound 3-(2-bromophenyl)-4-isopropoxycyclobut-3-ene-1,2-dione, as a yellow oil (2.16 g).

Workup

  1. waitthen kept at ambient temperature for 3 days
  2. customthe mixture obtained
  3. washwas washed with saturated aqueous ammonium chloride (225 ml)
  4. filtrationThe organic phase was filtered through a silica bed (5 cm diameter×1 cm depth)
  5. washthe collected solids were washed with diethyl ether (50 ml)
  6. customevaporated
  7. customto give a semi-solid brown oil, which
  8. customwas purified by flash chromatography on silica gel (loading in dichloromethane and eluting with 20% diethyl ether in petroleum ether (b.p. 40°-60° C.))

Sources & evidence

ORD record
ord-a426ebb4adcd429ea1945b4f8d3b4304
Source dataset
uspto-grants-1997_05
Patent number
US05627191

Reaction notes

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