Trimethyl orthoformate → 6-Bromo-5-chloro-2-methylbenzoxazole

HRID 530782Notes

Reaction equation

HRID 530782 reaction equation
[NH2:1][C:2]1[CH:7]=[C:6]([Cl:8])[C:5]([Br:9])=[CH:4]C=1O.[Yb+3].FC(F)(F)S([O-])(=O)=O.FC(F)(F)S([O-])(=O)=O.F[C:29](F)(F)S([O-])(=O)=O.[CH:36](OC)(OC)[O:37][CH3:38]>CCO>[Br:9][C:5]1[C:6]([Cl:8])=[CH:7][C:2]2[N:1]=[C:36]([CH3:29])[O:37][C:38]=2[CH:4]=1

Participants

5

Reactant 3

HCID 9005Trimethyl orthoformateHCID 2733225Ytterbium triflateHCID 584871002-Amino-5-bromo-4-chlorophenol

Product 1

HCID 584874386-Bromo-5-chloro-2-methylbenzoxazoleYield 90.3%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Conditions

Temperature
90 °C

Procedure

A mixture of 2-amino-5-bromo-4-chlorophenol (53) (4.746 g, 21.1 mmol), trifluoromethanesulfonic acid Ytterbium (III) salt (130 mg, 1% mol) and trimethyl orthoformate (4.03 ml, 1.5 eq.) in 15 ml EtOH was heated at 90° C. for 1 h. After cooling down to r.t. Crystalline formed was filtered, washed with MeOH, dried to give 4.694 g 54 as pale brown fine needles (yield: 90.3%)

Workup

  1. temperatureAfter cooling down to r.t
  2. customCrystalline formed
  3. filtrationwas filtered
  4. washwashed with MeOH
  5. customdried

Sources & evidence

ORD record
ord-c6d8f51add8c4551a7a1e8c30b0716f2
Source dataset
uspto-grants-2016_05
Patent number
US09353099B2

Reaction notes

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