Sodium Hydroxide → 3-Bromo-6,7-dihydro-5H-cyclopenta(b)pyridine

HRID 1742422

Reaction equation

HRID 1742422 reaction equation
[N:1]1[C:9]2[CH2:8][CH2:7][CH2:6][C:5]=2[CH:4]=[CH:3][CH:2]=1.[Al+3].[Cl-].[Cl-].[Cl-].[Br:14]Br.[OH-].[Na+]>CCOCC>[Br:14][C:3]1[CH:2]=[N:1][C:9]2[CH2:8][CH2:7][CH2:6][C:5]=2[CH:4]=1

Participants

6

Reactant 4

HCID 14798Sodium HydroxideHCID 24408BromineHCID 68292PyrindanHCID 6451240Aluminum(III) Chloride

Product 1

HCID 115212593-Bromo-6,7-dihydro-5H-cyclopenta(b)pyridine

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent

Procedure

To a solution of 6,7-dihydro-5H-[1]pyrindine (20 gm) and AlCl3 (56 gm) at 100° C. was added 10 mL of bromine over 2 hours, stirred an additional 15 minutes, cooled to room temperature, and poured over ice. The pH of the reaction was adjusted until it was basic with NaOH and then celite and ether were added and the mixture filtered. The filter cake was washed well with additional ether and the filtrate was extracted from the aqueous layer. The ether layer was washed with saturated aqueous NaCl solution, dried over MgSO4, filtered, and concentrated to dryness. The residue was chromatographed on silica gel using 10:1 hexane/ethyl acetate as the eluant to yield 4 gm of compound. 1H NMR (CDCl3): d 8.35 (s, 1 H), 7.60 (s, 1 H), 2.90 (m, 4 H), 2.10 (m, 2 H).

Workup

  1. additionpoured over ice
  2. filtrationthe mixture filtered
  3. washThe filter cake was washed well with additional ether
  4. extractionthe filtrate was extracted from the aqueous layer
  5. washThe ether layer was washed with saturated aqueous NaCl solution
  6. dry with materialdried over MgSO4
  7. filtrationfiltered
  8. concentrationconcentrated to dryness
  9. customThe residue was chromatographed on silica gel using 10:1 hexane/ethyl acetate as the eluant

Sources & evidence

ORD record
ord-538f16fac4a14554845341b535fa28eb
Source dataset
uspto-grants-1994_08
Patent number
US05338740

Linked notes

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