Bromine → tert-butyl 7-bromo-2H,3H,4H-pyrido[3,2-b][1,4]oxazine-4-carboxylate
Reaction equation
[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][O:11][C:10]2[CH:14]=[CH:15][CH:16]=[N:17][C:9]1=2)=[O:7])([CH3:4])([CH3:3])[CH3:2].[Br:18]Br>CO>[C:1]([O:5][C:6]([N:8]1[CH2:13][CH2:12][O:11][C:10]2[CH:14]=[C:15]([Br:18])[CH:16]=[N:17][C:9]1=2)=[O:7])([CH3:4])([CH3:2])[CH3:3]Participants
4
Procedure
To a solution of 4-(tert-butoxycarbonyl)-3,4-dihydro-2H-pyrido[3,2-b]-1,4-oxazine (2.0 g, 8.46 mmole) in MeOH (40 mL) was added Br2 (0.53 mL, 10.2 mmole) dropwise at 0° C. After 1 hr the mixture was concentrated. The residue was taken up in 1:1 Et2O/hexanes and filtered. The filtrate was concentrated under reduced pressure to give the title compound (1.27 g, 48%) as an oil which solidified under vacuum: 1H NMR (400 MHz, CDCl3) δ 8.10 (s, 1H), 7.33 (s, 1H), 4.25 (m, 2H), 3.92 (m, 2H), 1.54 (s, 9H).
Workup
- concentrationAfter 1 hr the mixture was concentrated
- filtrationfiltered
- concentrationThe filtrate was concentrated under reduced pressure
Sources & evidence
- ORD record
- ord-ef4076f883f84b41866b988c04c5d51e
- Source dataset
- uspto-grants-2007_07
- Patent number
- US07250424B2
Reaction notes
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