Methyl iodide → 5-[2-Isobutoxy-5-(methylsulfanyl)-3-pyridinyl]-2-methyl-3-propyl-2,6-dihydro-7h-pyrazolo[4,3-d]pyrimidin-7-one

Beteiligte Stoffe

Reaktionsschritte

The title compound of example 141 (500 mg, 1.07 mmol) and thiourea (90 mg, 1.18 mmol) were suspended in N,N-dimethylformamide (3 ml), degassed at 70° C., and treated with bis(triethylphosphine)nickel(II) chloride (20 mg, 0.05 mmol). Sodium cyanoborohydride (80 μl of 1M solution in THF, 0.08 mmol) was added, and the resultant black reaction mixture heated for ¾ h before further bis(triethylphosphine)nickel(II) chloride (60 mg, 0.16 mmol) and sodium cyanoborohydride (160 μl of 1M solution in THF, 0.16 mmol) were added and the reaction mixture heated for a further 6 h. The green reaction mixture was allowed to cool to room temperature and calcium oxide (90 mg, 1.6 mmol) added. After 1 h, methyl iodide (150 ?l, 2.4 mmol) was added and the mixture stirred for a further 1 h. The reaction mixture was diluted with ethyl acetate (20 ml) and citric acid (10% aq, 20 ml), the organic phase separated and washed with further citric acid (2×20 ml), brine (20 ml) and dried (MgSO4) to afford crude 5-[2-isobutoxy-5-(methylsulfanyl)-3-pyridinyl]-2-methyl-3-propyl-2,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one.

Herkunft & Nachweise