Reaktion #638992

Reaktionsgleichung

sodium hydrogencarbonate

methyl 3,4-dihydro-2H-1,4-benzoxazine-6-carboxylate

diisopropylethylamine

diisopropylethylamine

3-(pyrrolidin-3-yl)pyridine

triphosgene

→

methyl 4-[(3-(pyridin-3-yl)pyrrolidin-1-yl)carbonyl]-3,4-dihydro-2H-1,4-benzoxazine-6-carboxylate

Ausbeute 139.9%

Lösungsmittel

dichloromethane

dichloromethane

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.WAITthe reaction mixture is left
2. 2
   workup.STIRRINGthe reaction mixture is stirred for eighteen hours
3. 3
   ExtraktionThe aqueous phase is extracted three times with dichloromethane
4. 4
   Waschenwashed with water and with a saturated aqueous sodium chloride solution
5. 5
   Trocknendried over sodium sulfate
6. 6
   Sonstigethe solvent is evaporated under reduced pressure

Vorschrift

1.8 g of methyl 3,4-dihydro-2H-1,4-benzoxazine-6-carboxylate, 93.2 ml of dichloromethane and 4.62 ml of diisopropylethylamine are placed in a 250 ml round-bottomed flask under a nitrogen atmosphere. 1.38 g of triphosgene are added at 0° C. and then the reaction mixture is left stirring at ambient temperature for three hours. 1.62 ml of diisopropylethylamine and 1.45 g of 3-(pyrrolidin-3-yl)pyridine are subsequently added and the reaction mixture is stirred for eighteen hours. A saturated aqueous sodium hydrogencarbonate solution and dichloromethane are added. The aqueous phase is extracted three times with dichloromethane. The organic phases are combined, washed with water and with a saturated aqueous sodium chloride solution and dried over sodium sulfate and then the solvent is evaporated under reduced pressure. The residue is chroratographed on silica gel with a dichloromethane/methanol 95/5 mixture. 2.39 g of methyl 4-[(3-(pyridin-3-yl)pyrrolidin-1-yl)carbonyl]-3,4-dihydro-2H-1,4-benzoxazine-6-carboxylate are obtained.

Quelle