Acetic Acid → 1-Isobutyl-4-[2-(3,3,4,4-tetramethylcyclopent-1-enyl)phenyl]piperazine

HRID 32171Notes

Reaction equation

HRID 32171 reaction equation
[CH3:1][C:2]1([CH3:21])[C:6]([CH3:8])([CH3:7])[CH2:5][C:4]([C:9]2[CH:14]=[CH:13][CH:12]=[CH:11][C:10]=2[N:15]2[CH2:20][CH2:19][NH:18][CH2:17][CH2:16]2)=[CH:3]1.[CH:22](=O)[CH:23]([CH3:25])[CH3:24].C(O[BH-](OC(=O)C)OC(=O)C)(=O)C.[Na+].C(O)(=O)C.C(=O)([O-])O.[Na+]>O1CCCC1.C(OCC)(=O)C>[CH2:22]([N:18]1[CH2:17][CH2:16][N:15]([C:10]2[CH:11]=[CH:12][CH:13]=[CH:14][C:9]=2[C:4]2[CH2:5][C:6]([CH3:7])([CH3:8])[C:2]([CH3:21])([CH3:1])[CH:3]=2)[CH2:20][CH2:19]1)[CH:23]([CH3:25])[CH3:24]

Participants

8

Reactant 5

HCID 176Acetic Acid2×HCID 6561Isobutyraldehyde2×HCID 516892Sodium BicarbonateHCID 5049666Sodium triacetoxyborohydride2×HCID 231425251-[2-(3,3,4,4-Tetramethylcyclopent-1-enyl)phenyl]piperazine

Product 1

HCID 113597681-Isobutyl-4-[2-(3,3,4,4-tetramethylcyclopent-1-enyl)phenyl]piperazineYield 18%

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolventHCID 8857Ethyl AcetateSolvent

Procedure

To a solution of the 1-[2-(3,3,4,4-tetramethylcyclopent-1-enyl)phenyl]piperazine (20 mg, 0.0703 mmol) produced in Example (54d) in tetrahydrofuran (1 mL) were added isobutyraldehyde (6.6 mg, 0.0914 mmol), sodium triacetoxyborohydride (19.4 mg, 0.0914 mmol) and acetic acid (0.0076 mL, 0.134 mmol), followed by stirring for 4 hours at room temperature. After further adding isobutyraldehyde (6.6 mg, 0.0914 mmol), sodium triacetoxyborohydride (19.4 mg, 0.0914 mmol) and acetic acid (0.0076 mL, 0.134 mmol) to the mixture, stirring was continued for 3 hours at room temperature. Saturated aqueous solution of sodium hydrogencarbonate was added to the reaction mixture and extraction was performed three times with ethyl acetate. The obtained organic layers were concentrated and the resultant residue was purified by NH silica gel column chromatography (ethyl acetate/heptane) to give 4.3 mg of 1-isobutyl-4-[2-(3,3,4,4-tetramethylcyclopent-1-enyl)phenyl]piperazine as a colorless oil.

Workup

  1. stirringstirring
  2. waitwas continued for 3 hours at room temperature
  3. concentrationThe obtained organic layers were concentrated
  4. customthe resultant residue was purified by NH silica gel column chromatography (ethyl acetate/heptane)

Sources & evidence

ORD record
ord-2d67f4498dad4ad49053518bd1a7461a
Source dataset
uspto-grants-2008_09
Patent number
US07425554B2

Reaction notes

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