Potassium Carbonate → 5-(5-Bromopyridin-2-yl)-4-ethyloxazole

HRID 1672574Notes

Reaction equation

HRID 1672574 reaction equation
[N+:1]([CH:3](S(C1C=CC(C)=CC=1)(=O)=O)[CH2:4][CH3:5])#[C-:2].[Br:16][C:17]1[CH:18]=[CH:19][C:20]([CH:23]=[O:24])=[N:21][CH:22]=1.C([O-])([O-])=O.[K+].[K+]>CO>[Br:16][C:17]1[CH:18]=[CH:19][C:20]([C:23]2[O:24][CH:2]=[N:1][C:3]=2[CH2:4][CH3:5])=[N:21][CH:22]=1

Participants

5

Reactant 3

HCID 11430Potassium CarbonateHCID 98775625-Bromopyridine-2-carbaldehydeHCID 204671891-Ethyl-1-tosylmethyl isocyanide

Product 1

HCID 666965965-(5-Bromopyridin-2-yl)-4-ethyloxazoleYield 88%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A mixture of 1-(1-isocyanopropylsulfonyl)-4-methylbenzene (1.98 g, 8.87 mmol), 5-bromopicolinaldehyde (1.65 g, 8.87 mmol), and K2CO3 (1.47 g, 10.6 mmol) in MeOH (45 mL) was heated at reflux overnight. The reaction was cooled to ambient temperature and concentrated in vacuo. Water was added to the residue and the product was extracted with EtOAc. The combined organic extract was washed with brine, dried (Na2SO4), filtered, and concentrated in vacuo. The crude product was chromatographed on silica gel (Analogix® 25×60 column, 10%-50% EtOAc/hexanes) to yield 1.97 g (88%) of the title compound. 1H NMR (300 MHz, CDCl3) δ 8.68 (dd, J=2.4, 0.5, 1H), 7.89-7.82 (m, 2H), 7.55-7.49 (m, 1H), 3.06 (q, J=7.5, 2H), 1.29 (t, J=7.5, 3H). MS (DCI+) m/z 253/255 (M+H).

Workup

  1. temperaturewas heated
  2. temperatureat reflux overnight
  3. concentrationconcentrated in vacuo
  4. additionWater was added to the residue
  5. extractionthe product was extracted with EtOAc
  6. extractionThe combined organic extract
  7. washwas washed with brine
  8. dry with materialdried (Na2SO4)
  9. filtrationfiltered
  10. concentrationconcentrated in vacuo
  11. customThe crude product was chromatographed on silica gel (Analogix® 25×60 column, 10%-50% EtOAc/hexanes)

Sources & evidence

ORD record
ord-ee852080ca7f4a08b4c52efa68c8e990
Source dataset
uspto-grants-2011_08
Patent number
US07998993B2

Reaction notes

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