Boron tribromide → HCID 69275281, compound

HRID 2375399Notes

Reaction equation

HRID 2375399 reaction equation
[C:1]([C:4]1[C:5]([C:22](=[O:24])[CH3:23])=[C:6]([CH3:21])[N:7]([C:10]2[CH:15]=[CH:14][C:13]([O:16]CC)=[CH:12][C:11]=2[O:19][CH3:20])[C:8]=1[CH3:9])(=[O:3])[CH3:2].B(Br)(Br)Br>C(Cl)Cl>[C:22]([C:5]1[C:4]([C:1](=[O:3])[CH3:2])=[C:8]([CH3:9])[N:7]([C:10]2[CH:15]=[CH:14][C:13]([OH:16])=[CH:12][C:11]=2[O:19][CH3:20])[C:6]=1[CH3:21])(=[O:24])[CH3:23]

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 69277513HCID 69277513, compound

Product 1

HCID 69275281HCID 69275281, compound

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a stirring solution of crude 1-[4-acetyl-1-(4-ethoxy-2-methoxy-phenyl)-2,5-dimethyl-1H-pyrrol-3-yl]-ethanone prepared as above (90 mg, 0.3 mmol) in 5.0 mL of CH2Cl2 at 0° C. was added BBr3 (1.0 M in CH2Cl2, 0.9 mL, 0.9 mmol). After 1 h at 0° C., it was warmed to rt and stirred for an additional 2 h before it was quenched with saturated aq. NaHCO3 solution (5 mL). It was extracted with EtOAc (2×10 mL), and the combined organic extracts were washed with dried with MgSO4, filtered, and concentrated in vacuo to afford the crude product as a yellow oil. This crude material was purified by automated chromatography on silica gel (using 20-50%EtOAc/hexanes gradient) to give the major product 1-[4-acetyl-1-(4-hydroxy-2-methoxy-phenyl)-2,5-dimethyl-1H-pyrrol-3-yl]-ethanone as pale yellow oil: MS (ESI) 302 (M+H)+; In this reaction, small amount (˜10%) of minor product 1-[4-acetyl-1-(2,4-dihydroxy-phenyl)-2,5-dimethyl-1H-pyrrol-3-yl]-ethanone was also isolated as clear colorless oil: MS (ESI) 288 (M+H)+.

Workup

  1. customwas quenched with saturated aq. NaHCO3 solution (5 mL)
  2. extractionIt was extracted with EtOAc (2×10 mL)
  3. washthe combined organic extracts were washed
  4. dry with materialwith dried with MgSO4
  5. filtrationfiltered
  6. concentrationconcentrated in vacuo
  7. customto afford the crude product as a yellow oil
  8. customThis crude material was purified by automated chromatography on silica gel (using 20-50%EtOAc/hexanes gradient)

Sources & evidence

ORD record
ord-1e5834894c5c4b1d9c9a929fc17e1624
Source dataset
uspto-grants-2008_12
Patent number
US07465730B2

Reaction notes

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