Ethyl orthoformate → 3-(1-diethoxymethyl-4,4-dimethyl-2-oxo-1,4-dihydro-2H-benzo[d][1,3]oxazin-6-yl)-5-fluoro-benzonitrile
Reaction equation
[CH3:1][C:2]1([CH3:22])[O:7][C:6](=[O:8])[NH:5][C:4]2[CH:9]=[CH:10][C:11]([C:13]3[CH:14]=[C:15]([CH:18]=[C:19]([F:21])[CH:20]=3)[C:16]#[N:17])=[CH:12][C:3]1=2.[CH2:23]([O:25][CH:26](OCC)[O:27][CH2:28][CH3:29])[CH3:24]>>[CH2:23]([O:25][CH:26]([O:27][CH2:28][CH3:29])[N:5]1[C:4]2[CH:9]=[CH:10][C:11]([C:13]3[CH:14]=[C:15]([CH:18]=[C:19]([F:21])[CH:20]=3)[C:16]#[N:17])=[CH:12][C:3]=2[C:2]([CH3:22])([CH3:1])[O:7][C:6]1=[O:8])[CH3:24]Participants
Conditions
- Temperature
- 160 °C
Procedure
A mixture of 3-(4,4-Dimethyl-2-oxo-1,4-dihydro-2H-benzo[d][1,3]oxazin-6yl)-5-fluoro-benzonitrile (0.25 g, 0.84 mmol) and triethylorthoformate (50 mL) was heated at 160° C. for 12 hours. The excess triethylorthoformate was removed in vacuo and purification via chromatography (silica gel, 20% ethyl acetate/hexane) gave 3-(1-diethoxymethyl-4,4-dimethyl-2-oxo-1,4-dihydro-2H-benzo[d][1,3]oxazin-6-yl)-5-fluoro-benzonitrile (0.116 g, 33%) as a white solid: mp 123-124° C.; 1H-NMR (DMSO-d6) δ7.97 (d, 1H, J=8.68 Hz), 7.66 (bs, 1H), 7.53-7.44 (m, 2H), 7.35-7.32 (m, 2H), 6.65 (s, 1H), 3.88-3.78 (m, 2H), 3.73-3.61 (m, 2H), 1.77 (s, 6H), 1.27 (t, 6H, J=7.05 Hz); MS (ESI) m/z 295 ([M−H]−, 100%, lower MW ion consistent with loss of diethyl acetal); Anal. Calc. For C22H23FN2O4: C, 66.32, H, 5.82, N, 7.03. Found: C, 65.89, H, 5.92, N, 6.66.
Workup
- customThe excess triethylorthoformate was removed in vacuo and purification via chromatography (silica gel, 20% ethyl acetate/hexane)
Sources & evidence
- ORD record
- ord-ba832817a6944eb4bbe26080a65d3638
- Source dataset
- uspto-grants-2003_05
- Patent number
- US06566358B2
Reaction notes
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