2-(Bromomethyl)-1,3-dichloro-5-methoxybenzene → 1-[4-(tert-Butyl-dimethyl-silanyloxy)-cyclohexyl]-3-(2,6-dichloro-4-methoxy-benzyl)-pyrrolidin-2-one

Participants

Reaction Steps

Using the procedure to synthesize Example 202 and using the reagents of cis-1-[4-(tert-butyl-dimethyl-silanoxy)-cyclohexyl]-pyrrolidin-2-one (Preparation 17) and 2-Bromomethyl-1,3-dichloro-5-methoxy-benzene (Preparation 62). Warm reaction to room temperature, quench with NH4Cl (sat), dilute with diethyl ether, wash with brine, dry over sodium sulfate, filter and evaporate to an oil. Chromatography (silica, 100% hexanes to 75:25 hexanes/EtoAc) yields 1-[4-(tert-Butyl-dimethyl-silanyloxy)-cyclohexyl]-3-(2,6-dichloro-4-methoxy-benzyl)-pyrrolidin-2-one in 49% yield. The silylether is dissolved in THF, treated with 10.0 equivalents of HCl (conc) and allowed to stir at room temperature for 3 h, quench reaction with water, dilute with EtOAc, adjust pH to 7.0, separate, dry over sodium sulfate, filter and evaporate provides the titled compound in 84% yield: Mass spectrum (API-ES positive) m/z=372 (M+H).

Provenance & Evidence