Triethylamine → 5-[2-Isobutoxy-5-(3-methyl-1,2,4-oxadiazol-5-yl)-3-pyridinyl]-2-methyl-3-propyl-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one

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Reaction Steps

5-(5-Iodo-2-isobutoxy-3-pyridinyl)-2-methyl-3-propyl-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one (Example 22) (200 mg, 0.42 mmol) and N′-hydroxyethanimidamide (EP 795 328) (95 mg, 1.28 mmol) were suspended in toluene (4 mL) and triethylamine (86 mg, 0.85 mmol) was added. Pd(PPh3)2Cl2 (15 mg, 0.02 mmol) was added and placed in a preheated oil bath at 95° C. under 1 atmosphere carbon monoxide. After 4 h a further portion of acetamidoxime (50 mg), triethylamine (43 mg) and Pd(PPh3)2Cl2 (15 mg) were added and stirring was continued at 95° C. for 14 h. The cooled reaction mixture was diluted with ethyl acetate and washed with water and brine, dried (MgSO4), filtered and evaporated. Purification by flash column chromatography (gradient elution from dichloromethane:1% methanol:dichloromethane) gave 70 mg product.

Provenance & Evidence