Potassium Hydroxide → HCID 18549727, compound

Participants

Reaction Steps

A mixture of 1.90 g (3.69 mmol) of the preceding ester and 4.05 ml (4.06 mmol) of 1 N KOH in 15 ml of tetrahydrofuran was stirred at room temperature for 2 days and then 0.75 ml of 1 N KOH was added and the mixture was refluxed overnight. The solvent was removed under vacuum and the toluene (25 ml) added to the residue and removed under vacuum. The residue was triturated with ethyl acetate and the solid filtered and dried under vacuum to give 1.6 g of 4-{[4-(4-chlorophenyloxy) benzenesulfonyl]methylamino}-1,3-dimethyl-1H-pyrazolo[3,4-b]pyridine-5-carboxylic acid, potassium salt. Following the procedure of Example 52, 1.60 g of the preceding potassium salt was converted to the title compound to obtain 1.82 g of solid. This solid was purified on thick layer silica gel plates with 4% CH3OH in ethyl acetate as solvent to give 0.59 g of light yellow solid, m.p. 120° C. dec.

Provenance & Evidence