Sodium hydride → Methyl 3,5-dibromo-4-[(1Z)-3-tert-butoxy-3-oxoprop-1-enyl]benzoate

HRID 394207

Reaktionsgleichung

Reaktionsgleichung von HRID 394207
O(P([CH2:17][C:18]([O:20][C:21]([CH3:24])([CH3:23])[CH3:22])=[O:19])(OC1C=CC=CC=1)=O)C1C=CC=CC=1.[H-].[Na+].[Br:27][C:28]1[CH:29]=[C:30]([CH:35]=[C:36]([Br:40])[C:37]=1[CH:38]=O)[C:31]([O:33][CH3:34])=[O:32]>C1COCC1>[Br:27][C:28]1[CH:29]=[C:30]([CH:35]=[C:36]([Br:40])[C:37]=1/[CH:38]=[CH:17]\[C:18]([O:20][C:21]([CH3:24])([CH3:23])[CH3:22])=[O:19])[C:31]([O:33][CH3:34])=[O:32]

Komponenten

5

Edukt 3

HCID 24758Sodium hydrideHCID 10689048Tert-butyl (diphenoxyphosphoryl)acetateHCID 22647908Methyl 3,5-dibromo-4-formylbenzoate

Produkt 1

HCID 69919932Methyl 3,5-dibromo-4-[(1Z)-3-tert-butoxy-3-oxoprop-1-enyl]benzoate

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 8028TetrahydrofuranLösungsmittel2×

Reaktionsbedingungen

Temperatur
-78 °C

Versuchsvorschrift

To a solution of tert-butyl (diphenoxyphosphoryl)acetate (267 mg) in THF (7.5 mL) at 0° C. under nitrogen was added sodium hydride and the mixture stirred for 15 min until gas evolution ceased. This anion mixture was then cooled to −78° C. and a solution of methyl 3,5-dibromo-4-formylbenzoate (262 mg) in THF (7.5 mL) was added dropwise. The reaction mixture was stirred at −78° C. for an additional 40 min before being quenched with saturated ammonium chloride solution, extracted into ethyl acetate, dried over MgSO4 and concentrated. The residue was purified by column chromatography on silica gel eluting with 90% hexane:10% ethyl acetate to give the title compound which also contained 20% of the E double-bond isomer. No attempt was made to separate these isomers at this stage. 1H NMR (500 MHz, CDCl3): 88.23 (s, 1H, E isomer); 8.21 (s, 1H, Z isomer); 7.57 (d, J=16.3 Hz, 1H, E isomer); 6.76 (d, J=11.9 Hz, 1H, Z isomer); 6.38 (d, J=16.3 Hz, 1H E isomer); 6.12 (d, J=11.9 Hz, 1H Z isomer); 3.954 (s, 3H, E isomer); 3.948 (s, 3H, Z isomer); 1.28 (s, 9H, both isomers). Mass spectrum: m/z 365 (M+H-t-Bu).

Aufarbeitung

  1. stirringThe reaction mixture was stirred at −78° C. for an additional 40 min
  2. custombefore being quenched with saturated ammonium chloride solution
  3. extractionextracted into ethyl acetate
  4. dry with materialdried over MgSO4
  5. concentrationconcentrated
  6. customThe residue was purified by column chromatography on silica gel eluting with 90% hexane

Quellen und Nachweise

ORD-Eintrag
ord-0ba89197d0b34a4baaf4efa435e5d758
Quelldatensatz
uspto-grants-2004_10
Patentnummer
US06809199B2

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