Potassium Carbonate → 1-(3,4-Dihydro-2H-1-benzopyran-6-yl)piperazine

HRID 2270933Notes

Reaction equation

HRID 2270933 reaction equation
[NH2:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[O:8][CH2:7][CH2:6][CH2:5]2.Cl.Cl[CH2:14][CH2:15][NH:16][CH2:17][CH2:18]Cl.C(=O)([O-])[O-].[K+].[K+]>ClC1C=CC=CC=1>[O:8]1[C:9]2[C:4](=[CH:3][C:2]([N:1]3[CH2:18][CH2:17][NH:16][CH2:15][CH2:14]3)=[CH:11][CH:10]=2)[CH2:5][CH2:6][CH2:7]1

Participants

5

Reactant 3

HCID 11430Potassium CarbonateHCID 522769Bis(2-chloroethyl)amine hydrochlorideHCID 132978913,4-Dihydro-2H-1-benzopyran-6-amine

Product 1

HCID 154850101-(3,4-Dihydro-2H-1-benzopyran-6-yl)piperazine

Reagents, catalysts & solvents 1

HCID 7964ChlorobenzeneSolvent

Procedure

A solution of 6-aminochroman from part 2 of this example (0.300 g, 2.013 mmol), bis-(2-choroethyl)amine hydrochloride (0.539 g, 3.020 mmol) and potassium carbonate (0.278 g, 2.013 mmol) in 10 mL chlorobenzene is heated at reflux for 24 h . The dark brown reaction mixture is then partitioned between 3N NaOH and methylene chloride. The organic layer is separated, dried over Mg2SO4, filtered and concentrated. Purification by flash column chromatography (5% methanol-methylene chloride) affords 0.157 g (36%) of 1-(chroman-6-yl)piperazine as a white solid, TLC Rf 0.35 (elution with 10% hanol-methylene chloride).

Workup

  1. temperatureat reflux for 24 h
  2. customThe dark brown reaction mixture is then partitioned between 3N NaOH and methylene chloride
  3. customThe organic layer is separated
  4. dry with materialdried over Mg2SO4
  5. filtrationfiltered
  6. concentrationconcentrated
  7. customPurification by flash column chromatography (5% methanol-methylene chloride)
  8. customaffords
  9. wash0.157 g (36%) of 1-(chroman-6-yl)piperazine as a white solid, TLC Rf 0.35 (elution with 10% hanol-methylene chloride)

Sources & evidence

ORD record
ord-68c91c1c109f4f22a994bf65d09519d5
Source dataset
uspto-grants-2001_12
Patent number
US06333329B2

Reaction notes

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