Carbon Dioxide → 4-Methoxy-1H-pyrrolo[2,3-b]pyridine

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Reaction Conditions

Reaction Steps

To 4-chloro-1H-pyrrolo[2,3-b]pyridine [2,3 g, Reference Example 64] in a stainless steel pressure vessel was added sodium hydroxide (2 g), and methanol (40 mL). The pressure vessel was sealed and heated at 170° C. for 4 hours. After cooling, water (100 mL) was added and the mixture was neutralised by addition of excess solid carbon dioxide pellets (30 g). After concentration to a slurry and filtration, the residue was washed twice with water (5 mL) to afford 4-methoxy-1H-pyrrolo[2,3-b]pyridine as a solid. To a mixture of 4-methoxy-1H-pyrrolo[2,3-b]pyridine (5.85 g) in toluene (150 mL) and water (150 mL) was added potassium hydroxide pellets (2.5 g), 4-methylbenzene sulfonyl chloride (7.53 g) and tetra-n-butyl ammonium hydrogen sulfate (0.02 g). This mixture was stirred at room temperature for 20 hours then extracted four times with ethyl acetate (100 mL). The combined organic extracts were concentrated and then subjected to flash column chromatography on silica eluting with a mixture of ethyl acetate and heptane (35:65, v/v) to afford the title compound as a white solid.

Provenance & Evidence