Reaktion #330931

Reaktionsgleichung

ammonium chloride

methyl (4-oxo-4,10-dihydro-9-oxa-3-thiabenzo[f]azulen-6-yl)acetate

bromocyclopropane

magnesium

→

captioned compound

Ausbeute 79.0%

Methyl (4-Cyclopropyl-4-hydroxy-4,10-dihydro-9-oxa-3-thiabenzo[f]azulen-6-yl)acetate

Ausbeute 79.0%

Lösungsmittel

THF

THF

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturwhile heating
2. 2
   workup.ADDITIONAfter the termination of dropwise addition
3. 3
   Temperaturthe mixture was refluxed
4. 4
   Temperaturunder heating for an additional 2 hours
5. 5
   Temperaturto air-cool
6. 6
   Temperaturpreviously chilled in an ice bath
7. 7
   Extraktionthe mixture was extracted with ethyl acetate
8. 8
   WaschenThe organic layer was washed with an aqueous saturated sodium chloride solution
9. 9
   Trocknendried over anhydrous sodium sulfate
10. 10
    workup.DISTILLATIONThe solvents were distilled off under a reduced pressure
11. 11
    Sonstigethe residue obtained
12. 12
    Sonstigewas purified by silica gel column chromatography (hexane-ethyl acetate=5:1)

Vorschrift

An anhydrous THF (50 mL) solution of bromocyclopropane (8.3 mL) was added dropwise to a metal magnesium (2.5 g), while heating. After the termination of dropwise addition, an anhydrous THF (20 mL) was added thereto, and the mixture was refluxed under heating for an additional 2 hours. Thereafter, the reaction mixture was allowed to air-cool, and this solution was added dropwise to an anhydrous THF (30 mL) solution of methyl (4-oxo-4,10-dihydro-9-oxa-3-thiabenzo[f]azulen-6-yl)acetate (10.0 g) previously chilled in an ice bath. After stirring the mixture for 30 minutes, an aqueous saturated ammonium chloride solution was added to the reaction mixture, and the mixture was extracted with ethyl acetate. The organic layer was washed with an aqueous saturated sodium chloride solution, and thereafter dried over anhydrous sodium sulfate. The solvents were distilled off under a reduced pressure, and the residue obtained was purified by silica gel column chromatography (hexane-ethyl acetate=5:1), to give 9.0 g (79%) of the captioned compound as an oily product.

Quelle