Dichloromethane → Ethyl 1-(2-acetoxyethyl)-4-bromopyrrole-2-glyoxalate

HRID 638308Notes

Reaction equation

HRID 638308 reaction equation
[Br:1]Br.[C:3]([O:6][CH2:7][CH2:8][N:9]1[CH:13]=[CH:12][CH:11]=[C:10]1[C:14](=[O:20])[C:15]([O:17][CH2:18][CH3:19])=[O:16])(=[O:5])[CH3:4].ClCCl>CCCCCC.C(OCC)(=O)C>[C:3]([O:6][CH2:7][CH2:8][N:9]1[CH:13]=[C:12]([Br:1])[CH:11]=[C:10]1[C:14](=[O:20])[C:15]([O:17][CH2:18][CH3:19])=[O:16])(=[O:5])[CH3:4]

Participants

5

Reactant 3

HCID 6344DichloromethaneHCID 24408BromineHCID 12795013Ethyl 1-(2-acetoxyethyl)pyrrole-2-glyoxalate

Product 1

HCID 12795028Ethyl 1-(2-acetoxyethyl)-4-bromopyrrole-2-glyoxalateYield 56.3%

Reagents, catalysts & solvents 1

HCID 21226206Ethyl acetate hexaneSolvent

Procedure

Three ml. (58.3 mmole) of bromine is added in a dropwise manner to a stirred solution of 14.77 g. (58.3 mmole) of ethyl 1-(2-acetoxyethyl)pyrrole- 2-glyoxalate in 200 ml. anhydrous dichloromethane and cooled to -75° C. After the addition, the reaction is left at -75° C. for 2.5 hours and then the temperature is allowed to increase to room tempearture. The solvent is removed in vacuo, dichloromethane is added to the residue and the solution is washed successively with water, 10% sodium bicarbonate solution and water. The organic phase is dried over sodium sulfate, and the solvent is removed in vacuo. The crude product thus obtained (18.3 g) is subjected to column chromatography on Florisil (1 Kg) using hexane-ethyl acetate (9:1) as the eluting solvent. There is thus obtained upon removal of the solvent, 10.9 g (56%) of ethyl 1-(2-acetoxyethyl)-4-bromopyrrole-2-glyoxalate as an oil having the following physical constants:

Workup

  1. additionAfter the addition
  2. temperatureto increase to room tempearture
  3. customThe solvent is removed in vacuo, dichloromethane
  4. additionis added to the residue
  5. washthe solution is washed successively with water, 10% sodium bicarbonate solution and water
  6. dry with materialThe organic phase is dried over sodium sulfate
  7. customthe solvent is removed in vacuo
  8. customThe crude product thus obtained (18.3 g)

Sources & evidence

ORD record
ord-acc69b6f86bc49ec8104f1d98903cd17
Source dataset
uspto-grants-1985_12
Patent number
US04560699

Reaction notes

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