Diisopropylethylamine → N-[(3-bromo-4-methylphenyl)methyl]-N'-{[1,6-diethyl-4-(tetrahydro-2H-pyran-4-ylamino)-1H-pyrazolo[3,4-b]pyridin-5-yl]methyl}-2,6-pyridinedicarboxamide

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Reaction Steps

To a suspension of 6-[({[1,6-diethyl-4-(tetrahydro-2H-pyran-4-ylamino)-1H-pyrazolo[3,4-b]pyridin-5-yl]methyl}amino)carbonyl]-2-pyridinecarboxylic acid (50.8 g, 112 mmol) in a 2 L 3-neck flask was added dichloromethane (DCM) (600 mL) followed by DIPEA (98 ml, 561 mmol), giving a solution. To it was added TBTU (39.7 g, 123 mmol) and the mixture was then stirred at room temperature for 2 min whereupon 1-(3-bromo-4-methylphenyl)methanamine hydrochloride (29.2 g, 123 mmol) was added. The mixture was stirred under nitrogen at room temperature. After 2.5 h the mixture was partitioned between dichloromethane and water and the aqueous layer extracted well with dichloromethane. The combined organics were washed with water, saturated sodium bicarbonate, brine, dried (MgSO4), filtered and evaporated to give 95.5 g of a pale golden foam that was purified on a 750 g Companion XL silica cartridge, eluting with 0-100% ethyl acetate in dichloromethane over 8 column volumes. However, halfway through loading, the material started to crystallise on the column, blocking the loading so this material already on the column was eluted as above to give 30.01 gm, (26%) of a white solid (combined theoretical yield of the two preparations was 116.6 g). The lab HPLC showed 99.4% purity (retention time 2.22 min). LC-MS m/z 634, 636 (M+H)+, 1.06 min (ret time).

Provenance & Evidence