Tetrahydrofuran → 2-Bromo-3,4-dichloropyridine

HRID 20639Notes

Reaction equation

HRID 20639 reaction equation
C([N-]C(C)C)(C)C.[Li+].[Cl:9][C:10]1[CH:11]=[N:12][CH:13]=[CH:14][C:15]=1[Cl:16].C1COCC1.[Br:22]Br>O>[Br:22][C:11]1[C:10]([Cl:9])=[C:15]([Cl:16])[CH:14]=[CH:13][N:12]=1

Participants

6

Reactant 4

HCID 8028TetrahydrofuranHCID 24408BromineHCID 2724682Lithium diisopropylamideHCID 27360813,4-Dichloropyridine

Product 1

HCID 875569432-Bromo-3,4-dichloropyridine

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A solution of lithium diisopropylamide (7.0 mL, 2.0 M heptane/THF, 14.0 mmol) was added to a solution of 3,4-dichloropyridine (1.88 g, 12.7 mmol) and anhydrous THF (30 mL) at −78° C. under N2. After 1 h, bromine (0.71 mL, 14.0 mmol) was added. After an additional 30 min, the reaction was allowed to warm to rt and maintained for 30 min. The mixture was poured into water, extracted with EtOAc, dried, filtered, concentrated, and purified by silica gel chromatography (0→30% EtOAc/hexanes) to give 2-bromo-3,4-dichloropyridine after recrystallization from methanol. MS (ESI): 225.9.

Workup

  1. waitAfter an additional 30 min
  2. temperaturemaintained for 30 min
  3. extractionextracted with EtOAc
  4. customdried
  5. filtrationfiltered
  6. concentrationconcentrated
  7. custompurified by silica gel chromatography (0→30% EtOAc/hexanes)

Sources & evidence

ORD record
ord-a64acdfc81b54d9593942e7dd7b4bd16
Source dataset
uspto-grants-2010_06
Patent number
US07745646B2

Reaction notes

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