2-Chloro-6-(hydroxymethyl)-4-[2-(trimethylsilyl)ethynyl]pyridin-3-ol → [7-Chloro-2-(trimethylsilyl)furo[2,3-c]pyridin-5-yl]methanol

Participants

Reaction Steps

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.

Provenance & Evidence