Methanesulfonic Acid → (3R)-3-(2,6-Dichloro-4-hydroxy-benzyl)-1-(4,5,6,7-tetrahydro-1H-indazol-7-yl)-pyrrolidin-2-one

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Reaction Steps

To a solution of (R)-3-(4-benzyloxy-2,6-dichloro-benzyl)-1-(4,5,6,7-tetrahydro-1H-indazol-7-yl)-pyrrolidin-2-one (2.46 g, 5.23 mmol) in dimethylsulfide (28 mL), add methane sulfonic acid (8.23 g, 85.7 mmol) and stir the mixture vigorously under at room temperature for 18 hours. Remove the solvent in vacuo and dilute the residue with water, adjust the pH to pH=7 with 5 N NaOH, and extract the mixture several times with ethyl acetate and THF. After drying the combined organic layer (Na2SO4), filter and concentrate under vacuum to afford 2.20 g (100%) of the title compound. MS (m/z): 381 (M+).

Provenance & Evidence