Boron tribromide → HCID 53847727, Verbindung

HRID 1440861Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 1440861
B(Br)(Br)Br.Cl.[F:6][C:7]1[CH:8]=[CH:9][C:10]([O:26]C)=[C:11]2[C:16]=1[O:15][CH2:14][C@H:13]([N:17]([CH:21]([CH2:24][CH3:25])[CH2:22][CH3:23])[CH2:18][CH2:19][CH3:20])[CH2:12]2>C(Cl)Cl>[F:6][C:7]1[CH:8]=[CH:9][C:10]([OH:26])=[C:11]2[C:16]=1[O:15][CH2:14][C@H:13]([N:17]([CH:21]([CH2:22][CH3:23])[CH2:24][CH3:25])[CH2:18][CH2:19][CH3:20])[CH2:12]2

Komponenten

4

Edukt 2

HCID 25134Boron tribromideHCID 67703428HCID 67703428, Verbindung

Produkt 1

HCID 53847727HCID 53847727, VerbindungAusbeute 98,4 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 6344DichloromethaneLösungsmittel2×

Reaktionsbedingungen

Temperatur
0 °C

Versuchsvorschrift

Demethylation was done by addition of BBr3 (2.6 ml, 27.5 mmol) in 10 ml dry CH2Cl2 during 20 min., to a stirred, cooled solution (-70° C.) of (R)-8-fluoro-5-methoxy-3-(N-3-pentyl-N-n-propylamino)chroman hydrochloride (4.44 g, 12.8 mmol) in 100 ml dry CH2Cl2 under N2 atmosphere and dry conditions. The solution was stirred for 1 hour at -70° C., 1 hour at 0° C. and 1 hour at room temp. and was thereafter poured into 80 ml saturated NaHCO3 aq. under vigirous stirring. After 0.5 hour the layers where separated and the aqueous phase was extracted with 2×150 ml CH2Cl2. The combined organic layers where dried (Na2SO4) and evaporated. The crude product was purified by flash chromatography on silica with a gradient of petroleumether-petroleumether: EtOAc, 4:1 to give 3.72 g of (R)- 8-fluoro-5-hydroxy-3-(N-3-pentyl-N-n-propylamino)chroman (NAG 134) as an yellow-brown oil. [α]D22 -85° (c 1.02 in MeOH).

Aufarbeitung

  1. customdry conditions
  2. additionwas thereafter poured into 80 ml saturated NaHCO3 aq. under vigirous stirring
  3. customAfter 0.5 hour the layers where separated
  4. extractionthe aqueous phase was extracted with 2×150 ml CH2Cl2
  5. dry with materialThe combined organic layers where dried (Na2SO4)
  6. customevaporated
  7. customThe crude product was purified by flash chromatography on silica with a gradient of petroleumether-petroleumether

Quellen und Nachweise

ORD-Eintrag
ord-4f433ea60b3048cea99381059c3a42b5
Quelldatensatz
uspto-grants-1996_03
Patentnummer
US05500425

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