Diisobutylaluminum hydride → 2-(3,4-Dichlorophenyl)piperazine

HRID 443065Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 443065
[Cl:1][C:2]1[CH:3]=[C:4]([C:9]2[CH:14]=[N:13][CH:12]=[CH:11][N:10]=2)[CH:5]=[CH:6][C:7]=1[Cl:8].CC(C[AlH]CC(C)C)C>C1COCC1>[Cl:1][C:2]1[CH:3]=[C:4]([CH:9]2[CH2:14][NH:13][CH2:12][CH2:11][NH:10]2)[CH:5]=[CH:6][C:7]=1[Cl:8]

Komponenten

4

Edukt 2

HCID 14487Diisobutylaluminum hydrideHCID 155946712-(3,4-Dichlorophenyl)pyrazine

Produkt 1

HCID 42313562-(3,4-Dichlorophenyl)piperazineAusbeute 40 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 8028TetrahydrofuranLösungsmittel

Versuchsvorschrift

To a solution of 2-(3,4-dichlorophenyl)pyrazine (10 g, 44.43 mmol) in dry THF (150 mL) was added slowly a solution of DIBAL-H (1M in THF, 444.3 mL) through a dropping funnel at 10° C. under N2. The color of solution turned into red wine at the end of addition. The solution was gradually warmed up to room temperature overnight. After completion (checked by TLC) the reaction was quenched slowly by the addition of saturated Na2SO4 solution until no more H2 evolved. White precipitate was formed after stirring for 1.0 h. The precipitate was filtered off, rinsed with THF, dried over MgSO4 and evaporated to dryness. The crude material (10 g) was purified by flash chromatography on 300 g of flash grade silica gel in 7.5% NH3 -MeOH/CH2Cl2 to give 4.11 g (17.77 mmol, 40%) of 2-(3,4-dichloro-phenyl)piperazine. m.p. 74°-76° C.; FAB MS [M+1]+ 231.

Aufarbeitung

  1. additionThe color of solution turned into red wine at the end of addition
  2. customAfter completion (checked by TLC) the reaction was quenched slowly by the addition of saturated Na2SO4 solution until no more H2
  3. customWhite precipitate was formed
  4. filtrationThe precipitate was filtered off
  5. washrinsed with THF
  6. dry with materialdried over MgSO4
  7. customevaporated to dryness
  8. customThe crude material (10 g) was purified by flash chromatography on 300 g of flash grade silica gel in 7.5% NH3 -MeOH/CH2Cl2

Quellen und Nachweise

ORD-Eintrag
ord-762164f52bf94919a7144e44abf99b03
Quelldatensatz
uspto-grants-1999_04
Patentnummer
US05892039

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