Acetic Acid → Ethyl 2-cyano-3-(7,8-dimethoxy-2H-1-benzopyran-5-yl)propanoate

HRID 280032

Reaktionsgleichung

Reaktionsgleichung von HRID 280032
[C:1]([C:3](=[CH:9][C:10]1[C:15]2[CH:16]=[CH:17][CH2:18][O:19][C:14]=2[C:13]([O:20][CH3:21])=[C:12]([O:22][CH3:23])[CH:11]=1)[C:4]([O:6][CH2:7][CH3:8])=[O:5])#[N:2].CC1C(Br)=C(O)C(Br)=CC=1C1(C2C=C(Br)C(O)=C(Br)C=2C)OS(=O)(=O)C2C=CC=CC1=2.C([BH3-])#N.[Na+].C(O)(=O)C>C(O)C>[C:1]([CH:3]([CH2:9][C:10]1[C:15]2[CH:16]=[CH:17][CH2:18][O:19][C:14]=2[C:13]([O:20][CH3:21])=[C:12]([O:22][CH3:23])[CH:11]=1)[C:4]([O:6][CH2:7][CH3:8])=[O:5])#[N:2]

Komponenten

6

Edukt 4

HCID 176Acetic Acid2×HCID 6451Bromocresol GreenHCID 5003444Sodium cyanoborohydrideHCID 54507081Ethyl 2-cyano-3-(7,8-dimethoxy-2H-1-benzopyran-5-yl)propenoate

Produkt 1

HCID 20129780Ethyl 2-cyano-3-(7,8-dimethoxy-2H-1-benzopyran-5-yl)propanoate

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 702EthanolLösungsmittel2×

Versuchsvorschrift

A mixture of ethyl 2-cyano-3-(7,8-dimethoxy-2H-1-benzopyran-5-yl)-propenoate (19.8 g, 0.63 mole) in ethanol (500 mL) under nitrogen was treated with acidic acid (4 mL) and a trace of bromocresol green and heated to reflux. Heating was discontinued and sodium cyanoborohydride (4.4 g, 0.07 mole) in ethanol (100 mL) was co-added with additional acetic acid (11 mL). The mixture was stirred under nitrogen for 2 hr, acetic acid (10 mL) added and the ethanol removed under reduced pressure. The resultant yellow solid was taken up in ethyl acetate (250 mL) and successively extracted with water (125 mL), saturated sodium bicarbonate (3×100 mL) and water (100 mL), then dried over magnesium sulfate. The volatiles were removed under reduced pressure to leave an amber oil, 18.22 g (91.4%) which was used without further purification.

Aufarbeitung

  1. temperatureHeating
  2. customthe ethanol removed under reduced pressure
  3. extractionsuccessively extracted with water (125 mL), saturated sodium bicarbonate (3×100 mL) and water (100 mL)
  4. dry with materialdried over magnesium sulfate
  5. customThe volatiles were removed under reduced pressure
  6. customto leave an amber oil, 18.22 g (91.4%) which
  7. customwas used without further purification

Quellen und Nachweise

ORD-Eintrag
ord-5465ba6dfefa4988b66fa1857a9e3d92
Quelldatensatz
uspto-grants-1986_05
Patentnummer
US04587342

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