Pyrazolidine → 2-(4-fluorophenyl)-3-(2-methylsulfanyl-pyrimidin-4-yl)-6,7-dihydro-5H-pyrazolo[1,2-a]pyrazol-1-one

Participants

Reaction Conditions

Reaction Steps

To a solution of pyrazolidine (7.8 g, 54.16 mmol) in pyridine (100 mL) is added 2-(4-fluorophenyl)-3-(2-methylsulfanyl-pyrimidin-4-yl)-3-oxo-propionic acid methyl ester, 3, (11.5 g, 36.1 mmol). The reaction mixture is heated to 90° C. for 16 hours. The solvent is removed in vacuo and the resulting residue purified over silica (100% EtOAc, followed by 10% MeOH/EtOAc) to afford 3.9 g (37% yield) of the desired product as a yellow solid.

Provenance & Evidence