Hydrazine hydrate (1:1) → HCID 178434172, compound

Participants

Reaction Steps

To a 20 mL scintillation vial was charged ethyl 4-((6-acetyl-7-amino-3-(6-phenylpyridin-3-yl)pyrazolo[1,5-a]pyrimidin-5-yl)methyl)cyclohexanecarboxylate (Int-4o, 72 mg, 0.144 mmol). To this vial was added NMP (2 mL) followed by hydrazine monohydrate (1 mL). The reaction was stirred at room temperature for 18 hours. At 18 hours, the hydrazine monohydrate was removed in vacuo and the crude 4-((7-amino-6-(1-hydrazonoethyl)-3-(6-phenylpyridin-3-yl)pyrazolo[1,5-a]pyrimidin-5-yl)methyl)cyclohexanecarbohydrazide (Int-4p) was transferred into 2-5 mL microwave vessel. The vial was sealed and heated to 200° C. for 45 minutes in microwave. After 45 minutes, the NMP was removed in vacuo using chlorobenzene as a cosolvent. The residue was dried on high vacuum over night. The crude 4-((3-methyl-6-(6-phenylpyridin-3-yl)-1H-dipyrazolo[1,5-a:4′,3′-e]pyrimidin-4-yl)methyl)cyclohexanecarbohydrazide (Int-4q) was taken up in 4 N HCl in 1,4-dioxane (2 mL). To this was added H2O (1 mL). This solution was stirred at 70° C. for 2 hours. After 2 hours, the solvent was removed in vacuo. The residue was purified via reverse-phase preparatory HPLC to yield 4-((3-methyl-6-(6-phenylpyridin-3-yl)-1H-dipyrazolo[1,5-a:4′,3′-e]pyrimidin-4-yl)methyl)cyclohexanecarboxylic acid (5) (m+H=467.23, retention time=3.66 min).

Provenance & Evidence