Reaktion #45671
ord-d25f7f671b524bef9b839edaa7c4f18c
Reaktionsgleichung
Edukte
Reagenzien
Lösungsmittel
Reaktionsbedingungen
Aufarbeitung
- 1Temperaturwith cooling in a water bath
- 2workup.STIRRINGstirred for 30 hours
- 3workup.ADDITIONwas added to the reaction liquid
- 4Temperaturwith cooling with ice
- 5workup.STIRRINGby stirring at room temperature
- 6Sonstigethe reaction liquid
- 7Extraktionwas extracted with chloroform
- 8Trocknendried over anhydrous magnesium sulfate
- 9Filtrationfiltered
- 10Einengenthe filtrate was concentrated under reduced pressure
Vorschrift
Under nitrogen atmosphere, trimethylaluminium (1.03 M n-hexane solution, 57.9 ml, 59.6 mmol) was dropwise added to a dichloromethane (100 ml) solution of dimethylamine hydrochloride (4.86 g, 59.6 mmol) with cooling in a water bath, taking 30 minutes, and stirred for 65 minutes at room temperature. Subsequently, a dichloromethane (30 ml) solution of ethyl 6-bromo-4-cyano-7-fluoro-5-methyl-1,3-benzoxazole-2-carboxylate (I-126) (6.50 g, 19.9 mmol) was dropwise added and stirred for 30 hours. After the reaction, aqueous 1 N hydrochloric acid solution was added to the reaction liquid with cooling with ice, followed by stirring at room temperature, and the reaction liquid was extracted with chloroform. Next, the obtained organic layers were combined, dried over anhydrous magnesium sulfate, filtered, and the filtrate was concentrated under reduced pressure. The resulting residue was subjected to silica gel column chromatography, and the eluate with dichloromethane/methanol (100:1, v/v) gave the entitled compound (3.10 g, 48%) as a pale yellow solid. The fraction containing impurities was recovered and purified twice in the same manner to obtain the entitled compound (362 mg, 591 mg), and 4.05 g (62%) of the entitled compound was obtained in total.