Piperazine → 1-Tritylpiperazine

HRID 1111327Notes

Reaction equation

HRID 1111327 reaction equation
[NH:1]1[CH2:6][CH2:5][NH:4][CH2:3][CH2:2]1.CCN(CC)CC.[C:14]1([C:20](Cl)([C:27]2[CH:32]=[CH:31][CH:30]=[CH:29][CH:28]=2)[C:21]2[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=2)[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1>C(Cl)(Cl)Cl>[C:14]1([C:20]([C:21]2[CH:22]=[CH:23][CH:24]=[CH:25][CH:26]=2)([C:27]2[CH:28]=[CH:29][CH:30]=[CH:31][CH:32]=2)[N:1]2[CH2:6][CH2:5][NH:4][CH2:3][CH2:2]2)[CH:15]=[CH:16][CH:17]=[CH:18][CH:19]=1

Participants

5

Reactant 3

HCID 4837PiperazineHCID 6456Trityl chlorideHCID 8471Triethylamine

Product 1

HCID 114729311-Tritylpiperazine

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent2×

Procedure

Piperazine (5.0 g, 58.04 mmol) was dissolved in CHCl3 (100 ml) and Et3N (9 ml, 64.6 mmol) was added. This solution was heated to reflux and a solution of triphenylmethyl chloride (16.36 g, 58.68 mmol) in CHCl3 (100 ml) was added dropwise, via the reflux condenser, over a period of 4 hours. The reflux was then continued for 3 hours more and then was cooled and allowed to stand at room temperature overnight. A solid precipitated and was filtered off. The filtrate was evaporated to dryness to an oil which was partitioned between 10% aqueous Na2CO3 (150 ml) and CHCl3 (150 ml). The aqueous layer was washed with two additional portions of CHCl3 (2×150 ml) and the pooled organic layers were dried (MgSO4), filtered and evaporated to dryness to give a straw-colored syrup. This was purified on a silica gel 60 column (800 g) wet packed in CHCl3 and then developed with CHCl3 :MeOH (9:1) and then CHCl3 :MeOH (4:1). Fractions containing the required product were pooled and evaporated to dryness to give the title compound. Mass spec showed M+ at m/e 328. NMR (CDCl3, δ from TMS): 3.04 (br) piperazine methylenes; 7.06-7.58 (m) aromatics.

Workup

  1. temperatureThis solution was heated
  2. temperatureto reflux
  3. temperaturemore and then was cooled
  4. waitto stand at room temperature overnight
  5. customA solid precipitated
  6. filtrationwas filtered off
  7. customThe filtrate was evaporated to dryness to an oil which
  8. customwas partitioned between 10% aqueous Na2CO3 (150 ml) and CHCl3 (150 ml)
  9. washThe aqueous layer was washed with two additional portions of CHCl3 (2×150 ml)
  10. dry with materialthe pooled organic layers were dried (MgSO4)
  11. filtrationfiltered
  12. customevaporated to dryness
  13. customto give a straw-colored syrup
  14. customThis was purified on a silica gel 60 column (800 g)
  15. additionFractions containing the required product
  16. customevaporated to dryness

Sources & evidence

ORD record
ord-e0f9282749a64064acb41d3ef00eba1d
Source dataset
uspto-grants-1990_12
Patent number
US04980350

Reaction notes

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