2-Chloro-6-(hydroxymethyl)-4-[2-(trimethylsilyl)ethynyl]pyridin-3-ol → [7-Chloro-2-(trimethylsilyl)furo[2,3-c]pyridin-5-yl]methanol
反応式
[Cl:1][C:2]1[C:7]([OH:8])=[C:6]([C:9]#[C:10][Si:11]([CH3:14])([CH3:13])[CH3:12])[CH:5]=[C:4]([CH2:15][OH:16])[N:3]=1>CCO>[Cl:1][C:2]1[N:3]=[C:4]([CH2:15][OH:16])[CH:5]=[C:6]2[CH:9]=[C:10]([Si:11]([CH3:12])([CH3:14])[CH3:13])[O:8][C:7]=12参加物
3
実験手順
C3 (7.9 g, 31.2 mmol) and cuprous iodide (297 mg, 1.6 mmol) in 60 mL EtOH/60 mL TEA are added to a flask. The reaction is placed in an oil bath at 70° C. for 3.5 h, is cooled to rt, and concentrated in vacuo. The residue is partitioned between 100 mL 5% HCl and CH2Cl2 (4×50 mL). The combined organic layer is dried over MgSO4, filtered, and concentrated in vacuo to give 6.5 g of a crude amber solid. The crude material is chromatographed over 300 g silica gel (230-400 mesh) eluting with 30-40% EtOAc/hexane. Two sets of fractions with two different desired compounds are identified by TLC/UV. The two compounds eluted separately. The early-eluting pool of fractions is combined and concentrated to afford [7-chloro-2-(trimethylsilyl)furo[2,3-c]pyridin-5-yl]methanol (C5) as a white solid (46% yield). The later-eluting pool of fractions is combined and concentrated to provide (7-chlorofuro[2,3-c]pyridin-5-yl)methanol (C4) as a white solid (27% yield). MS (EI) for C8H6ClNO2, m/z: 183 (M)+ for C4. HRMS (FAB) calculated for C11H14ClNO2Si m/z: 255.0482, found 255.0481 for C5.