Hydrochloric Acid → 1-(5-Bromopyridin-2-yl)piperazine

HRID 1418321Notes

Reaction equation

HRID 1418321 reaction equation
C(O[C:6]([N:8]1[CH2:13][CH2:12][NH:11][CH2:10][CH2:9]1)=O)(C)(C)C.BrC1[CH:20]=[CH:19][C:18]([Br:21])=[CH:17][N:16]=1.C(N(C(C)C)CC)(C)C.Cl>CN1CCCC1=O.O>[Br:21][C:18]1[CH:19]=[CH:20][C:6]([N:8]2[CH2:9][CH2:10][NH:11][CH2:12][CH2:13]2)=[N:16][CH:17]=1

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 693532,5-DibromopyridineHCID 81531DiisopropylethylamineHCID 143452tert-Butyl piperazine-1-carboxylate

Product 1

HCID 164142271-(5-Bromopyridin-2-yl)piperazineYield 66.2%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 13387N-methyl-2-pyrrolidoneSolvent

Procedure

A mixture of 5.0 g of 1-t-butoxycarbonyl piperazine, 6.36 gm of 2,5-dibromopyridine and 10.4 gm diisopropylethylamine in 50 ml of 1-methyl-2-pyrolidinone is kept for 12 hours at 150° C. Upon cooling to ambient temperature and addition of 10 ml water, the mixture is acidified with concentrated hydrochloric acid heated for 15 minutes and upon cooling extracted 2×5 ml ethyl ether. The aqueous layer is then neutralized with aqueous ammonium hydroxide solution and extracted with ethyl acetate. The ethyl acetate extract is collected, washed with 20 ml water and dried over Na2SO4. The crude product (4.3 gm) obtained after removing the solvents solidifies upon standing. This material is used without further purification.

Workup

  1. temperatureheated for 15 minutes
  2. temperatureupon cooling
  3. extractionextracted 2×5 ml ethyl ether
  4. extractionextracted with ethyl acetate
  5. extractionThe ethyl acetate extract
  6. customis collected
  7. washwashed with 20 ml water
  8. dry with materialdried over Na2SO4

Sources & evidence

ORD record
ord-a50cc55431ff473fb09ccc9929b3c07b
Source dataset
uspto-grants-1999_03
Patent number
US05883094

Reaction notes

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