Potassium Carbonate → 1-(4-Hydroxyphenyl)-4-(benzoxazol-2-ylmethyl)piperazine

HRID 620043Notes

Reaction equation

HRID 620043 reaction equation
[OH:1][C:2]1[CH:7]=[CH:6][C:5]([N:8]2[CH2:13][CH2:12][NH:11][CH2:10][CH2:9]2)=[CH:4][CH:3]=1.Cl[CH2:15][C:16]1[O:17][C:18]2[CH:24]=[CH:23][CH:22]=[CH:21][C:19]=2[N:20]=1.C([O-])([O-])=O.[K+].[K+]>CN(C=O)C>[OH:1][C:2]1[CH:3]=[CH:4][C:5]([N:8]2[CH2:13][CH2:12][N:11]([CH2:15][C:16]3[O:17][C:18]4[CH:24]=[CH:23][CH:22]=[CH:21][C:19]=4[N:20]=3)[CH2:10][CH2:9]2)=[CH:6][CH:7]=1

Participants

5

Reactant 3

HCID 11430Potassium Carbonate2×HCID 92467p-(1-Piperazinyl)phenolHCID 20619892-(Chloromethyl)-1,3-benzoxazole

Product 1

HCID 48066221-(4-Hydroxyphenyl)-4-(benzoxazol-2-ylmethyl)piperazineYield 71.7%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
80 °C

Procedure

A mixture of 6.06 g (34 mmol) of 1-(4-hydroxyphenyl)piperazine and 5.36 g (32 mmol) of 2-chloromethylbenzoxazole in 100 ml of absolute DMF was warmed to 80° C., and 737 mg of powdered K2CO3 were added with stirring (under a nitrogen atmosphere) in each case after 10 minutes, after a further 25 minutes and after a further 60 minutes (total addition of 2.21 g (16 mmol) of K2CO3). The mixture was stirred for a further 3 hours at 80° C., the DMF was substantially removed by distillation in vacuo, and the residue was taken up in 200 ml of ether and 100 ml of water. After separating the phases, the aqueous phase was extracted a further twice with ether. The combined ether extracts were dried, filtered and evaporated in vacuo. The residue was taken up in diisopropyl ether, whereafter crystallization occurred. The crystalline substance was filtered off under suction. 7.10 g (71.7% of theory) of 1-(4-hydroxyphenyl)-4-(benzoxazol-2-ylmethyl)piperazine, melting point 155°-56° C., were obtained,

Workup

  1. waitafter a further 25 minutes
  2. stirringThe mixture was stirred for a further 3 hours at 80° C.
  3. customthe DMF was substantially removed by distillation in vacuo
  4. customAfter separating the phases
  5. extractionthe aqueous phase was extracted a further twice with ether
  6. dry with materialThe combined ether extracts were dried
  7. filtrationfiltered
  8. customevaporated in vacuo
  9. customThe residue was taken up in diisopropyl ether, whereafter crystallization
  10. filtrationThe crystalline substance was filtered off under suction

Sources & evidence

ORD record
ord-795c1401c2c24f4abae7174deb3ebc46
Source dataset
uspto-grants-1989_04
Patent number
US04818758

Reaction notes

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