1-[(3-Bromophenyl)(4-chlorophenyl)methyl]-4-methylpiperazine → HCID 20132434, compound

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Reaction Steps

The intermediate from Example 1, 1-(3-bromo-4'-chlorobenzhydryl)-4-methylpiperazine (1.10 g, 2.90 mmol), was dissolved in 10 mL of dry tetrahydrofuran and dried further over 4A molecular sieves for 24 hours. The solution was transferred to a dry flask under nitrogen and cooled to -78°. n-Butyllithium in hexane (1.1M, 2.6 ml) was added dropwise and the solution was stirred for 10 minutes at -78°. Carbon dioxide gas was bubbled into the reaction until the red solution turned yellow. The reaction was warmed to room temperature and the solvent was evaporated. The residue was dissolved in 20 mL of water and made basic with several drops of 1M sodium hydroxide. The aqueous solution was extracted with two 50 mL portion of ether and the pH was adjusted to 7-8 with 1M hydrochloric acid. After chilling in an ice bath, the precipitate was collected by filtration to give 341 mg (33%) of 3-(4-chloro-α-(4-methyl-1-piperazinyl)benzyl)benzoic acid as a white powder, m.p. 225°-230° (dec.). Calc. for C19H21ClN2O2. 0.75 H2O: C, 63.68; H, 6.33; N, 7.82; Cl, 9.89. Found: C, 63.68; H, 6.34; N, 7.82; Cl, 9.89.

Provenance & Evidence