Chloride → 5-(6-Bromo-2-pyridyl)-4-pentynoic acid methyl ester

HRID 977592Notes

Reaction equation

HRID 977592 reaction equation
Br[C:2]1[CH:7]=[CH:6][CH:5]=[C:4]([Br:8])[N:3]=1.[CH3:9][O:10][C:11](=[O:16])[C:12]#[C:13][CH2:14][CH3:15].[Cl-]>C(N(CC)CC)C.[Cu]I>[CH3:9][O:10][C:11](=[O:16])[CH2:12][CH2:13][C:14]#[C:15][C:2]1[CH:7]=[CH:6][CH:5]=[C:4]([Br:8])[N:3]=1

Participants

6

Reactant 3

HCID 312ChlorideHCID 122742,6-DibromopyridineHCID 904702-Pentynoic acid, methyl ester

Product 1

HCID 156617985-(6-Bromo-2-pyridyl)-4-pentynoic acid methyl esterYield 43.3%

Reagents, catalysts & solvents 2

HCID 24350Copper(1+) iodide; Copper(I) iodide; Cuprous iodide; Cuprous iodide (CuI)CatalystHCID 8471TriethylamineSolvent

Procedure

A solution of 4.73 g of 2,6-dibromopyridine in 150 ml of triethylamine is mixed under ice cooling with 2.69 g of pentynoic acid methyl ester, 350 mg of bis-triphenylphosphinepalladium(II) chloride and 48 mg of copper(I) iodide and the mixture is stirred for 1 hour. Then, the ice bath is removed and it is stirred for 3 hours at room temperature. The precipitate--consisting of 2,6-bis-(4-methoxycarbonyl-1-butinyl)-pyridine and triethylammonium bromide--is suctioned off and the filtrate is evaporated to dryness. The residue is chromatographed on silica gel with hexane/ethyl acetate=95/5 to 75/25. 2.32 g of 5-(6-bromo-2-pyridyl)-4-pentynoic acid methyl ester of melting point 59°-61° C. is obtained.

Workup

  1. customThen, the ice bath is removed
  2. stirringit is stirred for 3 hours at room temperature
  3. customthe filtrate is evaporated to dryness
  4. customThe residue is chromatographed on silica gel with hexane/ethyl acetate=95/5 to 75/25

Sources & evidence

ORD record
ord-f26ab3145d8d4fd990174786fecc2399
Source dataset
uspto-grants-1997_03
Patent number
US05614634

Reaction notes

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