Hydrochloric Acid → 6-chloro-5-fluoro-1H-pyrrolo[2,3-b]pyridine

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Reaction Conditions

Reaction Steps

To a stirred solution of 5-fluoro-1H-pyrrolo[2,3-b]pyridine 7-oxide (4.317 g, 28.38 mmol) in THF (150 mL) is added hexamethyldisilazane (6.54 mL, 31.22 mmol). The reaction mixture is cooled to 5° C. and methyl chloroformate (5.49 mL, 70.94 mmol) added dropwise. After stirring at 5° C. for 3 h, 2M sodium hydroxide (80 mL, 0.16 mol) is added dropwise, keeping temperature below 10° C. After 2 h, 2M hydrochloric acid solution is added until the mixture is at pH7. The reaction is poured onto brine (ca. 500 mL) and product extracted with CHCl3 (ca. 4×300 mL). The combined organic extracts are dried over magnesium sulphate, filtered, and concentrated in vacuo to give the title compound as a light brown solid (4.15 g, 24.33 mmol). MS (m/z): 171/173 (M+1). The following compounds are prepared essentially by the method of Preparation 31.

Provenance & Evidence