Thionyl Chloride → N-(5-Cyanopyrimidin-4-yl)-1-(2-fluorobenzyl)-1H-pyrazolo[3,4-b]pyridine-3-carboxamide

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Reaction Steps

At RT, 39.4 g (145 mmol) of 1-(2-fluorobenzyl)-1H-pyrazolo[3,4-b]pyridine-3-carboxylic acid (preparation described in US2010/004235, page 27) were initially charged, and then thionyl chloride (370 ml) was added. The suspension was heated to reflux for 2 h and the now clear solution was concentrated under reduced pressure. 100 mg (0.345 mmol) of the acid chloride thus prepared were initially charged in pyridine (1.0 ml) and then 41.5 mg (0.345 mmol) of 4-amino-5-cyanopyrimidine were added in portions. The mixture was stirred at RT for 7 h and then left to stand overnight. Subsequently, volatile constituents were removed under high vacuum, the residue was separated by means of preparative HPLC (eluent: acetonitrile/water with 0.1% formic acid gradient) and the product fractions were concentrated. This gave 30 mg (23% of theory) of the title compound in solid form.

Provenance & Evidence