Acetyl chloride → ethyl 4-acetyl-3,4-dihydro-2H-1,4-benzoxazine-2-carboxylate

HRID 253117

Reaction equation

[C:1](Cl)(=[O:3])[CH3:2].[O:5]1[CH:10]([C:11]([O:13][CH2:14][CH3:15])=[O:12])[CH2:9][NH:8][C:7]2[CH:16]=[CH:17][CH:18]=[CH:19][C:6]1=2.CCN(C(C)C)C(C)C>CN(C1C=CN=CC=1)C.ClCCl>[C:1]([N:8]1[CH2:9][CH:10]([C:11]([O:13][CH2:14][CH3:15])=[O:12])[O:5][C:6]2[CH:19]=[CH:18][CH:17]=[CH:16][C:7]1=2)(=[O:3])[CH3:2]

Participants

Conditions

Temperature: 25 °C

Procedure

Acetyl chloride (23 □L, 0.33 mmol) was added to a solution of (±)-ethyl 3,4-dihydro-2H-benzo[b][1,4]oxazine-2-carboxylate (Example 3a, 55 mg, 0.27 mmol), DMAP (1.6 mg, 0.013 mmol), and Hunig's base (63 □L, 0.36 mmol) in dichloromethane (2 mL). The solution was stirred at 25° C. for 24 h, then the reaction mixture was diluted with dichloromethane (60 mL) and the mixture was extracted with 0.1 M sodium carbonate (7 mL) and half-saturated brine (7 mL). The organic layer was dried over sodium sulfate and concentrated. Purification of the product by flash column chromatography (40% EtOAc/hexane) afforded the title compound (46 mg, 0.18 mmol). MS m/z: 250 (M+1).

Workup

extractionthe mixture was extracted with 0.1 M sodium carbonate (7 mL) and half-saturated brine (7 mL)
dry with materialThe organic layer was dried over sodium sulfate
concentrationconcentrated
customPurification of the product by flash column chromatography (40% EtOAc/hexane)

Sources & evidence

ORD record: ord-2483ed169b4746809d8061324c564d00
Source dataset: uspto-grants-2011_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07872009B2

Linked notes

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