Sodium Bicarbonate → N5-(1-Cyclopropylpiperidin-4-yl)-2-[1-(2-fluorobenzyl)-1H-pyrazolo[3,4-b]pyridin-3-yl]pyrimidine-4,5-diamine

Participants

Reaction Steps

200 mg (0.596 mmol) of 2-[1-(2-fluorobenzyl)-1H-pyrazolo[3,4-b]pyridin-3-yl]pyrimidine-4,5-diamine (synthesis described in US2004/67937; Example V) were initially charged in methanol (16 ml) and admixed with 75 μl (1.312 mmol) of acetic acid, and then 182 mg (1.312 mmol) of 1-cyclopropyl-4-piperidinone were added. After stirring at RT for 15 min, 104 mg (1.67 mmol) of sodium cyanoborohydride were added and the mixture was stirred at RT for 2.5 h. Subsequently, within 2 days, the above-stated amounts of reagents (1-cyclopropyl-4-piperidinone, acetic acid, sodium cyanoborohydride) were added three times, in order to achieve substantially full conversion. Thereafter, saturated aqueous sodium hydrogencarbonate solution (5 ml) was added and the mixture was stirred vigorously for 10 min. Subsequently, the mixture was extracted with water and ethyl acetate. The phases were separated and the aqueous phase was extracted twice with ethyl acetate. The combined organic phases were washed with saturated aqueous sodium chloride solution, dried over sodium sulfate, filtered, concentrated and then purified by means of preparative HPLC (acetonitrile:water (+0.05% formic acid) gradient). 165 mg of the title compound were obtained (60% of theory).

Provenance & Evidence