1,4-Dibromobenzene → 2-(4-Bromophenyl)pyridine

HRID 22919Notes

Reaction equation

HRID 22919 reaction equation
[Li]CCCC.Br[C:7]1[CH:12]=[CH:11][C:10]([Br:13])=[CH:9][CH:8]=1.Br[C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][N:16]=1>C1COCC1.[Cl-].[Cl-].[Zn+2].C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>[Br:13][C:10]1[CH:11]=[CH:12][C:7]([C:15]2[CH:20]=[CH:19][CH:18]=[CH:17][N:16]=2)=[CH:8][CH:9]=1

Participants

7

Reactant 3

HCID 78041,4-DibromobenzeneHCID 79732-BromopyridineHCID 178418339Butyllithium

Product 1

HCID 15152372-(4-Bromophenyl)pyridineYield 71%

Reagents, catalysts & solvents 3

HCID 3007855ZincchlorideCatalystHCID 178418397HCID 178418397, compoundCatalystHCID 8028TetrahydrofuranSolvent2×

Procedure

nBuLi (1.6M in hexanes, 34.4 mls, 55 mmol) was added dropwise to a stirred solution of 1,4-dibromobenzene (11.8 g, 50 mmol) in 100 ml of dry THF at −60° C. The mixture was stirred for 15 min at this temperature before a solution of ZnCl2 (0.5M in THF, 100 ml, 50 mmol) in THF was added dropwise. The mixture was allowed to warm to room temperature over 90 min, and then Pd(PPh3)4 (200 mg) was added, followed immediately by 2-bromopyridine (4.8 ml, 50 mmol). The whole was stirred at room temperature overnight, then evaporated to low (10 ml) volume and diluted with EtOAc (400 ml). The solution was washed with a solution of 32 g of EDTA in 200 ml water and brine (200 ml), dried (MgSO4) and evaporated to a yellow/green solid. This solid was purified by column chromatography using 1:1 hexane:DCM as eluant to provide the title product (8.3 g; 71%); m/z MH+ 234 (TS+); Found C, 56.61%, H, 3.37%, N, 5.90%; Calcd. C, 56.44%, H, 3.44%, N, 5.98%.

Workup

  1. additionwas added dropwise
  2. customevaporated to low (10 ml) volume
  3. additiondiluted with EtOAc (400 ml)
  4. washThe solution was washed with a solution of 32 g of EDTA in 200 ml water and brine (200 ml)
  5. dry with materialdried (MgSO4)
  6. customevaporated to a yellow/green solid
  7. customThis solid was purified by column chromatography

Sources & evidence

ORD record
ord-16d5ab4808964e80a08739c92e2f9e43
Source dataset
uspto-grants-2005_02
Patent number
US06849649B2

Reaction notes

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