Citric Acid → (2S)-2-(1-(3-chloropyridin-2-yl)-1H-pyrazolo[3,4-d]pyrimidin-4-yloxy)-3-((R)-1-methoxypropan-2-yloxy)-N-(5-methylpyridin-2-yl)propanamide

Participants

Reaction Conditions

Reaction Steps

Trimethylaluminium (0.334 mL, 0.67 mmol) was added to 5-methylpyridin-2-amine (69.1 mg, 0.64 mmol) in toluene (8 mL) cooled to 0° C. under nitrogen. The resulting solution was stirred at 0° C. for 20 minutes. (2S)-Methyl 2-(1-(3-chloropyridin-2-yl)-1H-pyrazolo[3,4-d]pyrimidin-4-yloxy)-3-((R)-1-methoxypropan-2-yloxy)propanoate (Intermediate Y8) (245 mg, 0.58 mmol) in toluene (2 mL) was added and the reaction was allowed to warm to room temperature and then heated at reflux for 24 hours. The reaction mixture was allowed to cool and neutralised with citric acid (1M, aq) and then diluted with water (50 mL) and ethyl acetate (50 mL). The organic layer was separated and the aqueous layer re-extracted with ethyl acetate (50 mL). The combined organics were dried (MgSO4), filtered and evaporated. The crude product was purified by preparative HPLC (Phenomenex Gemini C 18 110A (axia) column, 5μ silica, 19 mm diameter, 100 mm length), using decreasingly polar mixtures of water (containing 0.1% formic acid) and MeCN as eluents to afford the product (137 mg, 47.4%). 1H NMR (400 MHz, DMSO) δ 1.10 (d, 3H), 2.26 (s, 3H), 3.23-3.42 (m, 5H), 3.76-3.85 (m, 1H), 4.10-4.16 (m, 2H), 5.95-6.00 (m, 1H), 7.55-7.60 (m, 1H), 7.68-7.73 (m, 1H), 7.86 (d, 1H), 8.14-8.18 (m, 1H), 8.24-8.29 (m, 1H), 8.54 (s, 2H), 8.62-8.67 (m, 1H), 10.21 (s, 1H) m/z (ESI+) (M+H)+=498.16; HPLC tR=1.84 min.

Provenance & Evidence