Chloroform → 21-Bromo-3alpha-hydroxy-5alpha-pregnane-11,20-dione

HRID 918051Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 918051
[OH:1][C@@H:2]1[CH2:21][CH2:20][C@@:19]2([CH3:22])[C@@H:4]([CH2:5][CH2:6][C@@H:7]3[C@@H:18]2[C:17](=[O:23])[CH2:16][C@@:15]2([CH3:24])[C@H:8]3[CH2:9][CH2:10][C@@H:11]2[C:12](=[O:14])[CH3:13])[CH2:3]1.[Br:25]Br.C(Cl)(Cl)Cl>CO.C(Cl)(=O)C>[Br:25][CH2:13][C:12](=[O:14])[C@@H:11]1[C@:15]2([CH3:24])[C@H:8]([C@H:7]3[C@H:18]([C:17](=[O:23])[CH2:16]2)[C@:19]2([CH3:22])[C@H:4]([CH2:3][C@H:2]([OH:1])[CH2:21][CH2:20]2)[CH2:5][CH2:6]3)[CH2:9][CH2:10]1

Komponenten

6

Edukt 3

HCID 6212ChloroformHCID 24408BromineHCID 104845Alphaxalone

Produkt 1

HCID 8673346721-Bromo-3alpha-hydroxy-5alpha-pregnane-11,20-dione

Reagenzien, Katalysatoren, Lösungsmittel 2

HCID 6367Acetyl chlorideKatalysatorHCID 887MethanolLösungsmittel2×

Versuchsvorschrift

3α-Hydroxy-5α-pregnane-11,20-dione (1 g.) in stirred methanol (7 ml.) at 30° was treated with acetyl chloride (1 drop). After two minutes bromine (0.19 ml.) in methanol (4.5 ml.) was added dropwise. The solution being allowed to decolourise between the addition of each drop. The resulting clear solution was poured into chloroform (100 ml.), washed with water (3 × 50 ml.) dried (Na2SO4) and evaporated to a white froth (1.40 g.). Preparative t.l.c. afforded title compound (715 mg.) which crystallised from chloroform/ether as clusters of colourless needles, m.p. 160°-163°; [α]D + 109° (c 0.82).

Aufarbeitung

  1. additionto decolourise between the addition of each drop
  2. washwashed with water (3 × 50 ml.)
  3. dry with materialdried (Na2SO4)
  4. customevaporated to a white froth (1.40 g.)

Quellen und Nachweise

ORD-Eintrag
ord-0d76cb9859d64f4faf26ecdc095a8cd9
Quelldatensatz
uspto-grants-1976_07
Patentnummer
US03969345

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