Tetrahydrofuran → Dicyclohexyl ketone

Participants

Reaction Conditions

Reaction Steps

To an ice-cooled solution of 1-(3-cyanobenzyl)-4-(2-methoxyphenyl)piperazine (5.60 g, 18.2 mmol) in 250 mL of tetrahydrofuran was added a solution of cyclohexylmagnesium chloride in ethyl ether (27.3 mL, 2.0M) under nitrogen. The solution was slowly warmed to 25° C. and then brought to reflux. After 48 h of reflux, thin layer chromatography indicated that the reaction was complete. The reaction mixture was then cooled to 0° C., ice cold 6N HCl solution (200 mL) was added, and the reaction mixture was stirred at ambient temperature for 3 h. The reaction mixture was then poured into a separatory funnel and washed with ether. The aqueous layer was then basified with K2CO3 and then extracted with chloroform. The organic extracts were combined, dried (Na2SO4), and concentrated to provide a dark green-brown oil. This material was purified on flash silica gel (1% methanol-chloroform) to afford 7.88 g (quantitative yield) of expected cyclohexyl ketone as a brown oil whose 1H NMR in CDCl3 was consistent with the desired structure.

Provenance & Evidence