2-(Dimethylamino)ethanol → 2-(4-(8-oxa-3-azabicyclo[3.2.1]octan-3-yl)-6-chloro-1H-pyrazolo[3,4-d]pyrimidin-1-yl)-N,N-dimethylethanamine

Participants

Reaction Steps

To 6-chloro-4-(8-oxa-3-aza-bicyclo[3.2.1]oct-3-yl)-1H-pyrazolo[3,4-d]pyrimidine (1 g, 3.8 mmol), 2-(dimethylamino)ethanol (0.57 mL, 5.7 mmol) triphenylphosphine (1.5 g, 5.7 mmol) in THF (25 mL) is added DIAD (1.1 mL, 5.7 mmol) in drops over 5 min. After 2 h the mixture is concentrated in vacuo, diluted with ether and extracted with 1N aq HCl (2×). The aqueous layers are neutralized with NaOH and extracted with CH2Cl2. The organic layers are treated with 4N HCl in dioxane and concentrated in vacuo. The resulting solid was triturated with ether. Material from a reaction conducted with 0.37 g of pyrazolopyrimidine was combined with this material to give 1.29 g of 2-(4-(8-oxa-3-azabicyclo[3.2.1]octan-3-yl)-6-chloro-1H-pyrazolo[3,4-d]pyrimidin-1-yl)-N,N-dimethylethanamine as a solid. This material (0.5 g, 1.34 mmol) was treated with 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)aniline (0.44 g, 2.0 mmol), aq. Na2CO3 (1.84 mL, 2M), and tetrakis triphenylphosphine palladium (50 mg) in 1:1 toluene:ethanol (10 mL). The reaction mixture was heated in a microwave at 12° C. for 60 min. The reaction was repeated. The combined reaction mixtures were diluted with EtOAc and filtered to give a solid (0.51 g). The aq. Phase was washed with EtOAc and the combined organic layers concentrated in vacuo. Trituration of the residue gave a solid (0.28 g). The precipitates were combined to give 4-(4-(8-oxa-3-azabicyclo[3.2.1]octan-3-yl)-1-(2-(dimethylamino)ethyl)-1H-pyrazolo[3,4-d]pyrimidin-6-yl)aniline as a solid (0.79 g). A solution of this material (550 mg, 1.4 mmol) and triethylamine (1.05 mL) in dichloromethane was treated with triphosgene (208 mg, 0.7 mmol). After 30 min one eleventh of the solution was treated with excess methylamine (2N in THF). Reverse phase HPLC gave the title compound (39 mg) MS m/s=451.2 (M+H).

Provenance & Evidence