Water → 5-[2-Ethoxy-5-(4-ethylpiperazine-1-sulfonyl)pyridin-3-yl]-3-ethyl-2-(2-methoxyethyl)-2,4-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one

Participants

Reaction Steps

10 g (0.019 mol) of the compound of Example 8 and Example 102, 1-{6-ethoxy-5-[3-ethyl-6,7-dihydro-2-(2-methoxyethyl)-7-oxo-2H-pyrazolo[4,3-d]pyrimidin-5-yl]-3-pyridylsulfonyl}-4-ethylpiperazine ethyl acetate solvate, was charged followed by 12 ml/g (120 mls) of 16% water in ethyl alcohol. The slurry was heated to reflux to yield a solution and 6 ml/g (60 mls) distilled off at atmospheric pressure. The solution was then cooled to room temperature with crystallisation occurring at 40° C. The slurry was then cooled to 5-10° C. and granulated for 30 minutes following which it was filtered and washed with 2 ml/g ethyl alcohol (20 mls). The damp solid was dried in vacuo overnight at 55-60° C. to yield a white crystalline solid. (Yield 7.6 g, 76%).Melting Point 162-165° C.

Provenance & Evidence