2-Methylindole → HCID 9947106, compound

Participants

Reaction Conditions

Reaction Steps

A solution of 2-methylindole (500 mg, 3.81 mmol) in dry THF (20 ml) is cooled to −5° C. under a stream of argon. Thereafter, tert-butyllithium (4.19 mmol, 2.47 ml of a 1.7 M pentane solution) is cautiously added dropwise such that a reaction temperature of 0° C. is not thereby exceeded. When the addition has ended, the reaction mixture is stirred at 0° C. for 2 h. Thereafter, a solution of 4-benzyl-4-dimethylaminocyclohexanone (Ket-3, 880 mg, 3.81 mmol) in dry THF (7 ml) is added dropwise at 0° C. The mixture is stirred at 0° C. for 15 min and then at room temperature for 4 h. The reaction mixture is quenched with saturated ammonium chloride solution (20 ml), the organic phase is separated off and the aqueous phase is extracted four times with methylene chloride (20 ml). The combined organic phases are dried over sodium sulfate and thereafter the solvent is removed in vacuo. Purification is carried out by means of flash chromatography (silica gel, cyclohexane/EtOAc 8:2). 456 mg (33%) of the desired cyclohexanol with a melting point of m.p.=105-107° C. are obtained. Only 1 of 2 possible diastereoisomers is formed.

Provenance & Evidence