Sodium hydride → 2,2-dimethyl-propionic acid 6-(4-fluorophenyl)-7-(2-methylsulfanyl-pyrimidin-4-yl)-5-oxo-2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-2-yl ester

Participants

Reaction Conditions

Reaction Steps

2,2-Dimethyl-propionic acid 1-[2-(4-fluorophenyl)acetyl]-2-(methylsulfanyl-pyrimidine-4-carbonyl)-pyrazolidin-4-yl ester, 33, (300 mg, 0.651 mmol) is dissolved in THF (6 mL). This solution is then added dropwise via cannula to a suspension of NaH (29 mg of a 60% dispersion in mineral oil, 0.716 mmol) at −30° C. The reaction is allowed to gradually warm to 0° C. over 3 hours. The reaction is quenched with NH4Cl (sat. aq.) (1 mL). The mixture is stirred at room temperature, then concentrated in vacuo. The residue is diluted with tetrahydrofuran (50 mL) and the mixture filtered through Celite. The filtrate is concentrated in vacuo to give an orange oil. The crude product is purified over silica (100% ethyl acetate to 5% to 10% to 20% methyl alcohol/ethyl acetate) to afford 87 mg (30% yield) of the desired product as a yellow solid.

Provenance & Evidence