Methyl iodide → HCID 15586325, compound

Participants

Reaction Conditions

Reaction Steps

A solution consisting of 0.51 gm. (0.005 mole) diisopropylamine in 10 ml. tetrahydrofuran is chilled in an ice: methanol bath and 3 ml. of 1.68 N butyllithium in pentane is added. To this mixture is then added a solution consisting of 1.25 gm. (0.005 mole) 4-(p-chlorophenyl)-4-dimethylaminocyclohexanone (prepared in Example 2) in 20 ml. tetrahydrofuran. After 5 min. stirring, 1.42 gm. methyl iodide is added. This reaction is stirred for another 30 min. in the cold, and then it is allowed to warm up to 25° C. Stirring is continued for 21/2 hours, when 20 ml. saturated aqueous ammonium chloride is added. Benzene is also added. The organic solvents are removed by evaporation under reduced pressure. The residue thus obtained is transferred to a chromatographic column containing 200 ml. silica gel. The chromatogram is developed with 2 liters of a mixture of 3% methanol in methylene chloride followed by 2 liters of a mixture of 5% methanol in methylene chloride. The appropriate fractions as determined by TLC are combined. The solvent is removed by evaporation under reduced pressure giving the desired 4-(p-chlorophenyl)-2-methyl-4-dimethylaminocyclohexanone. The compound is recrystallized from diethyl ether to give an analytical sample having a melting point at 110° to 111° C. This is recognized to be the cis isomer by NMR spectroscopy.

Provenance & Evidence