Chlorosulfonic acid → 4,5-Diphenyl-4-oxazolin-2-one

HRID 2288897Notes

Reaction equation

HRID 2288897 reaction equation
Cl[C:2]1[O:3][C:4]([C:13]2[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=2)=[C:5]([C:7]2[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=2)[N:6]=1.ClS(O)(=O)=[O:21]>ClCCl>[C:7]1([C:5]2[NH:6][C:2](=[O:21])[O:3][C:4]=2[C:13]2[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=2)[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=1

Participants

4

Reactant 2

HCID 24638Chlorosulfonic acidHCID 131311622-Chloro-4,5-diphenyloxazole

Product 1

HCID 1512454,5-Diphenyl-4-oxazolin-2-oneYield 75%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Conditions

Temperature
0 °C

Procedure

2-Chloro-4,5-diphenyl-oxazole from Step 2 (1.53 g, 6 mmol) was added to chlorosulfonic acid cooled to 0° C. (20 mL), and the stirred solution was warmed to room temperature for 1.0 hour. The mixture was added dropwise to ice and dichloromethane (50 mL) with stirring. The resultant layers were separated, and the organic layer was washed once with water and added to a 0° C. stirred solution of ammonium hydroxide (10 mL). The mixture was stirred for 1.0 hour and extracted with dichloromethane (3×50 mL). The combined organic layers were washed with 1 N HCl followed by brine and water, dried over MgSO4 and concentrated. Recrystallization from ethyl acetate/hexanes gave a white solid (1.5 g, 75%): mp 158-159° C. 1H NMR (acetone-d6) 300 MHz δ 7.98 (d, J=8.7 Hz, 2H) 7.78 (d, J=8.7 Hz, 2H) 7.64-7.70 (m, 2H) 7.42-7.5 (m, 3H) 6.72 (bs, 2H). Anal. Calc'd. for C15H11N2O3SCl: C, 53.82; H, 3.31; N, 8.37. Found: C, 53.92; H, 3.32; N, 8.33.

Workup

  1. temperaturethe stirred solution was warmed to room temperature for 1.0 hour
  2. customThe resultant layers were separated
  3. washthe organic layer was washed once with water
  4. additionadded to a 0° C.
  5. stirringstirred solution of ammonium hydroxide (10 mL)
  6. stirringThe mixture was stirred for 1.0 hour
  7. extractionextracted with dichloromethane (3×50 mL)
  8. washThe combined organic layers were washed with 1 N HCl
  9. dry with materialdried over MgSO4
  10. concentrationconcentrated
  11. customRecrystallization from ethyl acetate/hexanes

Sources & evidence

ORD record
ord-3069bb662ed64527a8fdc9b44ae0cd40
Source dataset
uspto-grants-2000_07
Patent number
US06090834

Reaction notes

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