Formaldehyde → 4-Boc-1-methyl-2-phenylpiperazine

HRID 530623Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 530623
[C:1]1([CH:7]2[NH:12][CH2:11][CH2:10][N:9]([C:13]([O:15][C:16]([CH3:19])([CH3:18])[CH3:17])=[O:14])[CH2:8]2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.C=O.[C:22](O[BH-](OC(=O)C)OC(=O)C)(=O)C.[Na+]>CO.C(=O)(O)[O-].[Na+].C(OCC)(=O)C>[C:16]([O:15][C:13]([N:9]1[CH2:10][CH2:11][N:12]([CH3:22])[CH:7]([C:1]2[CH:2]=[CH:3][CH:4]=[CH:5][CH:6]=2)[CH2:8]1)=[O:14])([CH3:19])([CH3:18])[CH3:17]

Komponenten

7

Edukt 3

HCID 712FormaldehydeHCID 2735358Tert-butyl 3-phenylpiperazine-1-carboxylateHCID 5049666Sodium triacetoxyborohydride

Produkt 1

HCID 771800394-Boc-1-methyl-2-phenylpiperazineAusbeute 101 %

Reagenzien, Katalysatoren, Lösungsmittel 3

HCID 887MethanolLösungsmittelHCID 8857Ethyl AcetateLösungsmittelHCID 516892Sodium BicarbonateLösungsmittel

Versuchsvorschrift

To a mixture of tert-butyl 3-phenylpiperazine-1-carboxylate (288 mg, 1.1 mmol), and formaldehyde (185 mg, 6.16 mmol) in methanol (7 mL) was added sodium triacetoxyborohydride (949 mg, 4.48 mmol) at 0° C. After stirring for 3 h at room temperature, the reaction mixture was diluted with 10% sodium bicarbonate solution and ethyl acetate. The aqueous part was extracted with ethyl acetate and the combined organic part was dried over sodium sulfate, filtered, concentrated in vacuo. The residue was purified by flash chromatography (20/1 dichloromethane/methanol) to provide 4-methyl-3-phenyl-piperazine-1-carboxylic acid tert-butyl ester (307 mg, 101%). (M+H)+=277 m/e. To a solution of 4-methyl-3-phenyl-piperazine-1-carboxylic acid tert-butyl ester (307 mg, 1.11 mmol) in THF (3 mL) at 0° C. was added 4M HCl in dioxane (0.9 mL). The reaction mixture was stirred overnight and concentrated in vacuo. The residue was triturated with dichloromethane and filtered to provide 1-methyl-2-phenyl-piperazine dihydrochloride (290 mg), which was used as is for the next step.

Aufarbeitung

  1. extractionThe aqueous part was extracted with ethyl acetate
  2. dry with materialthe combined organic part was dried over sodium sulfate
  3. filtrationfiltered
  4. concentrationconcentrated in vacuo
  5. customThe residue was purified by flash chromatography (20/1 dichloromethane/methanol)

Quellen und Nachweise

ORD-Eintrag
ord-83653501d9f14647b6cac6428c8e8740
Quelldatensatz
uspto-grants-2016_05
Patentnummer
US09353096B2

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