Carbon Dioxide → Ethyl 1-(2-acetoxyethyl)-4-chloropyrrole-2-glycolate

HRID 67114Notes

Reaction equation

HRID 67114 reaction equation
C(=O)=O.[BH4-].[Na+].[C:6]([O:9][CH2:10][CH2:11][N:12]1[CH:16]=[C:15]([Cl:17])[CH:14]=[C:13]1[C:18](=[O:24])[C:19]([O:21][CH2:22][CH3:23])=[O:20])(=[O:8])[CH3:7]>CO.O.C(O)(=O)C.C(Cl)(Cl)(Cl)Cl>[C:6]([O:9][CH2:10][CH2:11][N:12]1[CH:16]=[C:15]([Cl:17])[CH:14]=[C:13]1[CH:18]([OH:24])[C:19]([O:21][CH2:22][CH3:23])=[O:20])(=[O:8])[CH3:7]

Participants

8

Reactant 3

HCID 280Carbon DioxideHCID 4311764Sodium borohydrideHCID 12795026Ethyl 1-(2-acetoxyethyl)-4-chloropyrrole-2-glyoxalate

Product 1

HCID 12795036Ethyl 1-(2-acetoxyethyl)-4-chloropyrrole-2-glycolate

Reagents, catalysts & solvents 4

HCID 176Acetic AcidSolventHCID 887MethanolSolvent2×HCID 962WaterSolvent2×HCID 5943Carbon TetrachlorideSolvent

Procedure

A solution of water (25 ml.) in methanol (300 ml.) is cooled in a dry ice:carbon tetrachloride:acetone bath to -30° and 23.7 g. of sodium borohydride is added thereto. When the violent reaction has subsided, there is added, in a drop wise manner, 40 g. (0.139 mol.) of ethyl 1-(2-acetoxyethyl)-4-chloropyrrole-2-glyoxalate dissolved in methanol (400 ml.) at a rate such that the temperature does not exceed -20°. The reaction is maintained at this temperature for two hours when there is added a solution of 21.5 ml. of acetic acid in 320 ml. water. The solution is stirred for a further 1 hour at -30° during which time a white precipitate forms. This solid is collected by filtration and dissolved in dichloromethane. The organic solution was washed with saturated sodium chloride solution, dried over sodium sulphate and evaporated in vacuo. There is obtained 33.15 g. of a solid product which is homogeneous by thin layer chromatography. Recrystallization from dichloromethane-hexane yields ethyl 1-(2-acetoxyethyl)-4-chloropyrrole-2-glycolate, m.p. 60°-61° C. (Formula VI where Y is Cl).

Workup

  1. customto -30°
  2. customWhen the violent reaction
  3. additionthere is added, in a drop wise manner, 40 g
  4. customdoes not exceed -20°
  5. temperatureThe reaction is maintained at this temperature for two hours when there
  6. additionis added a solution of 21.5 ml
  7. filtrationThis solid is collected by filtration
  8. dissolutiondissolved in dichloromethane
  9. washThe organic solution was washed with saturated sodium chloride solution
  10. dry with materialdried over sodium sulphate
  11. customevaporated in vacuo
  12. customThere is obtained 33.15 g
  13. customRecrystallization from dichloromethane-hexane

Sources & evidence

ORD record
ord-da7d7909125a46d69abc1bd7fc57c349
Source dataset
uspto-grants-1982_08
Patent number
US04344943

Reaction notes

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