Hydrochloric Acid → 2'-tert-butyl-1-(7-m ethoxy-1H-indazole-5-carbonyl)-4',6'-dihydrospiro[piperidine-4,5'-pyrazolo[3,4-c]pyridin]-7'(2'H)-one

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Reaction Steps

To a mixture of 2′-tert-butyl-4′,6′-dihydrospiro[piperidine-4,5′-pyrazolo[3,4-c]pyridin]-7′(2′H)-one hydrochloride salt (Intermediate 4, 25 mg, 0.075 mmol) and 7-methoxy-1-(tetrahydro-2H-pyran-2-yl)-1H-indazole-5-carboxylic acid (Intermediate 18, 25 mg, 0.090 mmol) in N,N-dimethylformamide (0.4 mL) was added triethylamine (0.05 mL, 0.37 mmol). The mixture was stirred for 5 minutes. Then 1-propanephosphonic acid cyclic anhydride (0.09 mL, 0.1 mmol, 50% solution in ethyl acetate) was added and the reaction was stirred at room temperature overnight. The reaction was diluted with water and extracted with ethyl acetate (3×). The combined organic layers were washed with brine, dried over sodium sulfate, filtered, and concentrated to a yellow gum. To this crude material was added hydrochloric acid (0.19 mL, 0.75 mmol, 4 M in dioxane). The mixture was stirred at room temperature overnight. The reaction was concentrated. Purification by reversed-phase HPLC gave the title compound (3.4 mg, 10%). +ESI (M+H) 437.3; HPLC retention time 2.12 minutes (Method A).

Provenance & Evidence