Reaktion #478452

Reaktionsgleichung

dimethylcarbonate

sodiumhydride

7,8-Dichloro-3,4-dihydro-2H-benzo[b]oxepin-5-one

dimethylcarbonate

hydrochloric acid

→

7,8-Dichloro-5-oxo-2,3,4,5-tetrahydro-benzo[b]oxepine-4-carboxylic acid methyl ester

Ausbeute 40.0%

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwas added dropwise at room temperature
2. 2
   TemperaturThe mixture was refluxed for two hours
3. 3
   ExtraktionThe resulting solution was extracted by ethyl acetate
4. 4
   TrocknenThe organic phase was dried over sodiumsulfate
5. 5
   Sonstigethe solvent removed in vacuo
6. 6
   workup.DISSOLUTIONThe residue was dissolved in diethyl ether

Vorschrift

A suspension of sodiumhydride in parrafin (0.35 g, 60%) was added to 5 ml dimethylcarbonate. To this suspension 7,8-Dichloro-3,4-dihydro-2H-benzo[b]oxepin-5-one (4.3 mmol) dissolved in 2 ml dimethylcarbonate was added dropwise at room temperature. The mixture was refluxed for two hours, cooled to room temperature and stirred overnight. 25 ml of 2 mol/l hydrochloric acid were added to the mixture. The resulting solution was extracted by ethyl acetate. The organic phase was dried over sodiumsulfate and the solvent removed in vacuo. The residue was dissolved in diethyl ether. 7,8-Dichloro-5-oxo-2,3,4,5-tetrahydro-benzo[b]oxepine-4-carboxylic acid methyl ester was obtained by crystallization from this solution in a yield of 40%. LC-MS 2.3 min, 289.0 (MH+), 2.8 min, 289.0 (MH+)

Quelle