1,1'-Carbonyldiimidazole → 4-[(4-Bromo-2-furyl)methyl]-3-{4-[(2-methoxyethyl)amino]-1,2,5-oxadiazol-3-yl}-1,2,4-oxadiazol-5(4H)-one
Reaction equation
[Br:1][C:2]1[CH:3]=[C:4]([CH2:7][NH:8][C:9]([C:12]2[C:16]([NH:17][CH2:18][CH2:19][O:20][CH3:21])=[N:15][O:14][N:13]=2)=[N:10][OH:11])[O:5][CH:6]=1.[C:22](N1C=CN=C1)(N1C=CN=C1)=[O:23]>C(OCC)(=O)C>[Br:1][C:2]1[CH:3]=[C:4]([CH2:7][N:8]2[C:22](=[O:23])[O:11][N:10]=[C:9]2[C:12]2[C:16]([NH:17][CH2:18][CH2:19][O:20][CH3:21])=[N:15][O:14][N:13]=2)[O:5][CH:6]=1Participants
Conditions
- Temperature
- 65 °C
Procedure
N-[(4-Bromo-2-furyl)methyl]-N′-hydroxy-4-[(2-methoxyethyl)amino]-1,2,5-oxadiazole-3-carboximidamide (7.3 g, 20.4 mmol) and 1,1′-carbonyldiimidazole (5.0 g, 30.5 mmol) were dissolved in ethyl acetate (72 mL). The reaction mixture was heated at 65° C. for 15 minutes. Ethyl acetate (70 mL) was added and the crude reaction was washed with 0.1 N hydrogen chloride in water (2×70 mL). The organic layer was dried over sodium sulfate and concentrated in vacuo. Purification by flash chromatography on silica gel with an eluent of ethyl acetate in hexanes gave the desired product (4.1 g, 90%). LCMS calculated for C12H13BrN5O5 (M+H)+: m/z=386.0, 388.0. 1H NMR (400 MHz, CD3OD): δ 7.88 (s, 1H), 6.67 (s, 1H), 6.39 (t, J=5.7 Hz, 1H), 5.07 (s, 2H), 3.50 (m, 2H), 3.41 (q, J=5.7 Hz, 2H), 3.25 (s, 3H).
Workup
- customthe crude reaction
- washwas washed with 0.1 N hydrogen chloride in water (2×70 mL)
- dry with materialThe organic layer was dried over sodium sulfate
- concentrationconcentrated in vacuo
- customPurification by flash chromatography on silica gel with an eluent of ethyl acetate in hexanes
Sources & evidence
- ORD record
- ord-5dce4c498e1145f680fe1a50ab8edd1e
- Source dataset
- uspto-grants-2012_01
- Patent number
- US08088803B2
Reaction notes
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