Sodium Carbonate → 2-(5-methyl-2-pyridyl)thiophene

HRID 1837954Notes

Reaction equation

HRID 1837954 reaction equation
[S:1]1[CH:5]=[CH:4][CH:3]=[C:2]1B(O)O.Br[C:10]1[CH:15]=[CH:14][C:13]([CH3:16])=[CH:12][N:11]=1.C([O-])([O-])=O.[Na+].[Na+]>COCCOC.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>[CH3:16][C:13]1[CH:14]=[CH:15][C:10]([C:2]2[S:1][CH:5]=[CH:4][CH:3]=2)=[N:11][CH:12]=1

Participants

6

Reactant 3

HCID 10340Sodium CarbonateHCID 5642162-Bromo-5-methylpyridineHCID 27339602-Thiopheneboronic acid

Product 1

HCID 110412352-(5-methyl-2-pyridyl)thiopheneYield 98%

Reagents, catalysts & solvents 2

HCID 178418397HCID 178418397, compoundCatalystHCID 80711,2-DimethoxyethaneSolvent

Procedure

A mixture of 2-thiopheneboronic acid (0.483 g, 3.78 mmol), 2-bromo-5-methylpyridine (0.5 g, 2.91 mmol), a solution of Na2CO3 (1M in H2O, 7.8 mL, 7.8 mmol) and a catalytic amount of Pd(PPh3)4 in DME (10 mL) was heated at the reflux temperature for 3 h., then allowed to cool to room temperature and poured onto ice. The resulting mixture was stirred for 10 min and extracted with CH2Cl2 (2×25 mL), dried (MgSO4) and concentrated under reduced pressure. The crude product was purified by flash chromatography (70% EtOAc/hex) to give 2-(5-methyl-2-pyridyl)thiophene (0.499 g, 98%): GC-MS m/z (rel abundance) 176 (MH+, 100%); 1H NMR (CDCl3) δ 1.39 (s, 3H), 7.15 (m, 1H), 7.39 (m, 1H), 7.61-7.43 (m, 3H), 8.41 (s, 1H).

Workup

  1. additionpoured onto ice
  2. extractionextracted with CH2Cl2 (2×25 mL)
  3. dry with materialdried (MgSO4)
  4. concentrationconcentrated under reduced pressure
  5. customThe crude product was purified by flash chromatography (70% EtOAc/hex)

Sources & evidence

ORD record
ord-8d67680eebcf45699d7d3d5a3b9e20d9
Source dataset
uspto-grants-2004_08
Patent number
US06784167B2

Reaction notes

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