1,3-Dibromopropane → Methyl (1R,4S)-1-(3-bromopropyl)-4-(2,5-dimethyl-1H-pyrrol-1-yl)cyclopent-2-ene-1-carboxylate

HRID 1400068Notes

Reaction equation

HRID 1400068 reaction equation
[CH3:1][C:2]1[N:3]([C@H:8]2[CH2:12][C@@H:11]([C:13]([O:15][CH3:16])=[O:14])[CH:10]=[CH:9]2)[C:4]([CH3:7])=[CH:5][CH:6]=1.[Br:17][CH2:18][CH2:19][CH2:20]Br>O1CCCC1>[Br:17][CH2:18][CH2:19][CH2:20][C@@:11]1([C:13]([O:15][CH3:16])=[O:14])[CH2:12][C@H:8]([N:3]2[C:2]([CH3:1])=[CH:6][CH:5]=[C:4]2[CH3:7])[CH:9]=[CH:10]1

Participants

4

Reactant 2

HCID 80011,3-DibromopropaneHCID 59700297(1R,4S)-methyl 4-(2,5-dimethyl-1H-pyrrol-1-yl)cyclopent-2-enecarboxylate

Product 1

HCID 89823513Methyl (1R,4S)-1-(3-bromopropyl)-4-(2,5-dimethyl-1H-pyrrol-1-yl)cyclopent-2-ene-1-carboxylate

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
-20 °C

Procedure

To a solution of Example 1B (16.5 g, 74.4 mmol) in tetrahydrofuran (200 ml) was added dropwise lithium hexamethyl bis(trimethylsilyl)amide (1 M in tetrahydrofuran, 119 mL) at −50° C. The reaction mixture was stirred for 1 hour at the same temperature. 1,3-Dibromopropane (150 g, 744 mmol) was added dropwise over 1 hour. The reaction mixture was allowed to warm to −20° C. and stirred at the same temperature for 1 hour. LCMS showed that the reaction was complete. The reaction mixture was quenched with an aqueous ammonium chloride solution (6%, 600 mL), and extracted with ethyl acetate. The organic fraction was washed with aqueous ammonium chloride (6%), brine, dried with sodium sulfate, filtered, and concentrated in vacuo. The residue was purified by silica gel column chromatography (petroleum ether:ethyl acetate=80:1) to give Example 1C.

Workup

  1. stirringstirred at the same temperature for 1 hour
  2. customThe reaction mixture was quenched with an aqueous ammonium chloride solution (6%, 600 mL)
  3. extractionextracted with ethyl acetate
  4. washThe organic fraction was washed with aqueous ammonium chloride (6%), brine
  5. dry with materialdried with sodium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated in vacuo
  8. customThe residue was purified by silica gel column chromatography (petroleum ether:ethyl acetate=80:1)
  9. customto give Example 1C

Sources & evidence

ORD record
ord-b4c5b5e6d41447c9bead8ea92f924cd4
Source dataset
uspto-grants-2014_12
Patent number
US08906911B2

Reaction notes

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