Potassium Carbonate → 5-(4-Bromophenyl)-4-ethyloxazole

HRID 1672580Notes

Reaction equation

HRID 1672580 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:24]=[CH:23][C:20]([CH:21]=[O:22])=[CH:19][CH:18]=1.C([O-])([O-])=O.[K+].[K+]>CO>[Br:16][C:17]1[CH:24]=[CH:23][C:20]([C:21]2[O:22][CH:2]=[N:1][C:3]=2[CH2:4][CH3:5])=[CH:19][CH:18]=1

Participants

5

Reactant 3

HCID 11430Potassium CarbonateHCID 707414-BromobenzaldehydeHCID 204671891-Ethyl-1-tosylmethyl isocyanide

Product 1

HCID 666967705-(4-Bromophenyl)-4-ethyloxazole

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A mixture of 1-(1-isocyanopropylsulfonyl)-4-methylbenzene (1.21 g, 5.40 mmol), 4-bromobenzaldehyde (1 g, 5 mmol), and K2CO3 (0.896 g, 6.49 mmol) in MeOH (27 mL) was heated at reflux overnight. The reaction was cooled to ambient temperature and the solvent was evaporated at reduced pressure. The residue was partitioned between water and EtOAc. The separated organic phase was washed with water and brine, dried (Na2SO4), filtered, and concentrated in vacuo. The crude product was dissolved in minimal toluene, loaded on silica gel, and eluted with 2 column volumes of hexane, then 10% to 50% EtOAc/hexanes. The result was 1.27 g (93%) of the title compound. 1H NMR (300 MHz, CDCl3) δ 7.84 (s, 1H), 7.60-7.54 (m, 2H), 7.49-7.43 (m, 2H), 2.78 (q, J=7.5, 2H), 1.32 (t, J=7.6, 3H). MS (DCI+) m/z 252/254 (M+H).

Workup

  1. temperaturewas heated
  2. temperatureat reflux overnight
  3. customthe solvent was evaporated at reduced pressure
  4. customThe residue was partitioned between water and EtOAc
  5. washThe separated organic phase was washed with water and brine
  6. dry with materialdried (Na2SO4)
  7. filtrationfiltered
  8. concentrationconcentrated in vacuo
  9. dissolutionThe crude product was dissolved in minimal toluene
  10. washeluted with 2 column volumes of hexane

Sources & evidence

ORD record
ord-98617a6edcb845ed8394373b6afe3cb2
Source dataset
uspto-grants-2011_08
Patent number
US07998993B2

Reaction notes

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