6-Ethenylpyrido[2,3-b]pyrazine → Pyrido[2,3-b]pyrazine-6-carbaldehyde
反応式
[CH:1]([C:3]1[CH:4]=[CH:5][C:6]2[C:7]([N:12]=1)=[N:8][CH:9]=[CH:10][N:11]=2)=C.O=O.[O:15]=[O+][O-]>CO>[N:11]1[CH:10]=[CH:9][N:8]=[C:7]2[N:12]=[C:3]([CH:1]=[O:15])[CH:4]=[CH:5][C:6]=12参加物
4
反応条件
- 温度
- -70 °C
実験手順
6-vinylpyrido[2,3-b]pyrazine (Intermediate 4.3) (1 g, 6.37 mmol, 1 eq.) was dissolved in methanol (20 mL) and cooled down to −70° C. A gentle flux of a mixture of oxygen/ozone was then bubbled through for 20 minutes. The reaction was monitored by TLC using cyclohexane/ethyl acetate (8/2). When the reaction was finished, dimethylsulfide (0.1 mL) was added and reaction was left at rt for 30 minutes. Methanol was evaporated under vacuum and 600 mg of pyrido[2,3-b]pyrazine-6-carbaldehyde was recovered. Crude material was analyzed without further purification (Intermediate 4.4). Amount: 0.60 g; Yield: 60%; Formula: C8H5N3O; HPLC Purity: 90%; HPLC (H2O TFA 0.1%-ACN TFA 0.05%): Rt (min); Area %=0.90 min; 90%; 1H NMR (DMSO-d6) δ 10.1 (l, 1H), 9.05 (s, 1H), 8.95 (s, 1H), 8.70 (d, 1H, J=8 Hz), 8.20 (d, 1H, J=8 Hz); LC-MS: M/Z ESI: Rt (min) 0.76 min, 158.13 (M+1).