Trityl chloride → 6-Bromo-3-trityl-3H-benzooxazol-2-one

HRID 1435560Notes

Reaction equation

HRID 1435560 reaction equation
[Br:1][C:2]1[CH:11]=[CH:10][C:5]2[NH:6][C:7](=[O:9])[O:8][C:4]=2[CH:3]=1.C(N(CC)CC)C.[C:19](Cl)([C:32]1[CH:37]=[CH:36][CH:35]=[CH:34][CH:33]=1)([C:26]1[CH:31]=[CH:30][CH:29]=[CH:28][CH:27]=1)[C:20]1[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=1.CCOC(C)=O>C(Cl)Cl>[Br:1][C:2]1[CH:11]=[CH:10][C:5]2[N:6]([C:19]([C:20]3[CH:25]=[CH:24][CH:23]=[CH:22][CH:21]=3)([C:32]3[CH:33]=[CH:34][CH:35]=[CH:36][CH:37]=3)[C:26]3[CH:27]=[CH:28][CH:29]=[CH:30][CH:31]=3)[C:7](=[O:9])[O:8][C:4]=2[CH:3]=1

Participants

6

Reactant 4

HCID 6456Trityl chlorideHCID 8471TriethylamineHCID 8857Ethyl AcetateHCID 298596-Bromo-2(3H)-benzoxazolone

Product 1

HCID 30970186-Bromo-3-trityl-3H-benzooxazol-2-one

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a solution of 6-bromo-3H-benzoxazol-2-one (15 g; ca. 0.07 mol, containing 8-9% 3H-benzooxazol-2-one) and triethylamine (11.1 mL, 0.08 mol) in DCM (250 mL) was added trityl chloride (21.5 g, 0.08 mol). The solution was stirred at room temperature for 18 h and was then washed with distilled water (3×250 mL), brine (250 mL) and dried (MgSO4), filtered and evaporated to give an off-white colored solid. The product was dissolved in refluxing EtOAc then allowed to cool to room temperature with constant stirring for several hours. The solids were collected (21.16 g) and the filtrate was concentrated until precipitation occurred, re-heated (reflux) for several hours and allowed to cool with stirring to encourage a second crystallization (7.88 g). NMR and HPLC indicated the product (29.04 g, 91%) was very clean.

Workup

  1. washwas then washed with distilled water (3×250 mL), brine (250 mL)
  2. dry with materialdried (MgSO4)
  3. filtrationfiltered
  4. customevaporated
  5. customto give an off-white colored solid
  6. dissolutionThe product was dissolved
  7. temperatureto cool to room temperature
  8. stirringwith constant stirring for several hours
  9. customThe solids were collected (21.16 g)
  10. concentrationthe filtrate was concentrated until precipitation
  11. temperaturere-heated
  12. temperature(reflux) for several hours
  13. temperatureto cool
  14. stirringwith stirring
  15. customa second crystallization (7.88 g)

Sources & evidence

ORD record
ord-d5e884730c2349679456aa2534b6ac7d
Source dataset
uspto-grants-2009_11
Patent number
US07618650B2

Reaction notes

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