Water → 6-Chloro-3-methyl-1-(tetrahydro-pyran-2-yl)-1H-pyrazolo[3,4-b]pyridine-4-carboxylic acid ethyl ester

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Reaction Steps

A mixture of 6-chloro-3-methyl-1H-pyrazolo[3,4-b]pyridine-4-carboxylic acid ethyl ester (28.5 g), 3,4-dihydro-2H-pyran (23.7 mL) and p-toluenesulfonic acid monohydrate (6.8 g) in THF (800 mL) was stirred at r.t. until the reaction was complete. The mixture was poured into water (1.5 l) and extracted with ethyle acetate (600 mL). The organic phase was dried over magnesium sulfate and concentrated in a vacuo. The crude product was purified by silica gel chromatography (heptane/ethyl acetate gradient). 37.8 g (98%) of the title compound were obtained.

Provenance & Evidence