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 1.68N 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 Preparation I, above) in 20 ml. tetrahydrofuran. After 5 min. stirring, 1.42 gm. methyl iodide is added. The reaction mixture 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 solvent phase is separated, washed initially with water and then with brine. 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. Fractions which are shown by TLC to contain product are collected and combined. The solvents are 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 with respect to the 4-amino substitutient, by NMR spectroscopy.

Provenance & Evidence