Piperazine → 5-Methyl-2-(piperazin-1-yl)-1,3-benzoxazole

HRID 378866Notes

Reaction equation

HRID 378866 reaction equation
[CH3:1][C:2]1[CH:3]=[CH:4][C:5]2[O:9][C:8](S)=[N:7][C:6]=2[CH:11]=1.P(Cl)(Cl)(Cl)(Cl)Cl.[NH:18]1[CH2:23][CH2:22][NH:21][CH2:20][CH2:19]1>C1(C)C=CC=CC=1>[CH3:1][C:2]1[CH:3]=[CH:4][C:5]2[O:9][C:8]([N:18]3[CH2:23][CH2:22][NH:21][CH2:20][CH2:19]3)=[N:7][C:6]=2[CH:11]=1

Participants

5

Reactant 3

HCID 4837PiperazineHCID 24819Phosphorus pentachlorideHCID 178423563HCID 178423563, compound

Product 1

HCID 225582065-Methyl-2-(piperazin-1-yl)-1,3-benzoxazole

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

A 100 mg portion of 5-methyl-2-mercaptobenzoxazole was suspended in 20 ml of anhydrous toluene, and the suspension was mixed with 150 mg of phosphorus pentachloride and heated under reflux for 1 hour. The reaction solution was cooled in an ice bath and, with stirring, 500 mg of piperazine was added thereto. After 30 minutes of stirring, the ice bath was removed to carry out 1 hour of stirring at room temperature, the reaction solution was mixed with saturated sodium bicarbonate aqueous solution, and then the water layer was washed with ethyl acetate and concentrated under a reduced pressure. Thereafter, the thus obtained mixture was purified by an LH-20 gel column chromatography (chloroform:methanol=1:1) to obtain the title compound (40 mg) in white color.

Workup

  1. temperatureheated
  2. temperatureunder reflux for 1 hour
  3. temperatureThe reaction solution was cooled in an ice bath
  4. stirringAfter 30 minutes of stirring
  5. customthe ice bath was removed
  6. stirringof stirring at room temperature
  7. additionthe reaction solution was mixed with saturated sodium bicarbonate aqueous solution
  8. washthe water layer was washed with ethyl acetate
  9. concentrationconcentrated under a reduced pressure
  10. customThereafter, the thus obtained mixture was purified by an LH-20 gel column chromatography (chloroform:methanol=1:1)

Sources & evidence

ORD record
ord-267e52439d294359b4739c9fe2acfa14
Source dataset
uspto-grants-2001_10
Patent number
US06297246B1

Reaction notes

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