Phosphorus oxychloride → Benzoxazole

HRID 842092Notes

Reaction equation

HRID 842092 reaction equation
Br[C:2]1[CH:7]=[C:6](Cl)[CH:5]=[C:4]([N:9](C2C=CC(OC)=C(OC3CCCC3)C=2)[C:10](=O)C)[C:3]=1[OH:27].P(Cl)(Cl)(Cl)=O>C1(C)C=CC=CC=1>[O:27]1[C:3]2[CH:2]=[CH:7][CH:6]=[CH:5][C:4]=2[N:9]=[CH:10]1

Participants

4

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 22618319HCID 22618319, compound

Product 1

HCID 9228BenzoxazoleYield 261.2%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

A suspension of 32.9 g (72.4 mmol) of 2-bromo-4-chloro-6-(3-cyclopentyloxy-4-methoxy-phenyl-acetylamino)-phenol in 400 ml of toluene and 39.7 ml (434 mmol) of phosphorus oxychloride was refluxed for 1.5 hours. Some solid material was filtered off and the filtrate evaporated to dryness in vacuo. The honey-like residue was suspended in 200 ml of sodium bicarbonate solution for 1 hours. The solid was collected, washed and dried at 25° C. to give 22.53 g (71.2%) of crude benzoxazole.

Workup

  1. temperaturewas refluxed for 1.5 hours
  2. filtrationSome solid material was filtered off
  3. customthe filtrate evaporated to dryness in vacuo
  4. customThe solid was collected
  5. washwashed
  6. customdried at 25° C.

Sources & evidence

ORD record
ord-b96891f31ece443ead69c061c9b34f38
Source dataset
uspto-grants-2002_04
Patent number
US06372770B1

Reaction notes

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