Methyl iodide → HCID 15586328, compound

Participants

Reaction Conditions

Reaction Steps

A solution consisting of 1.02 gm. (0.010 mole) diisopropylamine in 20 ml. tetrahydrofuran was chilled in an ice:methanol bath before 6 ml. of 1.68 N butyllithium in pentane is added. To this mixture is then added a solution consisting of 2.31 gm. (0.010 mole) of 4-dimethylamino-4-(p-tolyl)cyclohexanone (prepared in Example 14) and 40 ml. tetrahydrofuran. Five minutes later, 2.82 gm. methyl iodide is added, and the mixture is stirred for 45 min. in the cold. It is allowed to warm to 25° C. and stirring is continued for 5 hours, when the reaction mixture is diluted with a mixture of water and benzene. The organic layer is separated and washed first with water and then with brine. The organic solvents are removed by evaporation under reduced pressure, and the residual waxy solid thus obtained is transferred to a column of the grade silica gel 1" by 48". The chromatogram is developed with a solvent medium consisting of 7.5% methanol in chloroform and 20-ml. fractions are collected. The fractions which contain product (as determined by TLC) are combined. The solvent is removed by evaporation under reduced pressure, and the residue thus obtained is recrystallized from diethyl ether. There is thus obtained 1.01 gm. (39% yield) of the object compound 2-ethyl-4-dimethylamino-4-(p-tolyl)cyclohexanone having a melting point at 102° to 104.5° C. NMR suggests assignment of cis relationship of 2-methyl to 4-N(CH3)2.

Provenance & Evidence