Lithium diisopropylamide → Ethyl 2-(2-chloro-6-fluorophenyl)-3-(4-methylcyclohexyl)-3-oxopropionate

Participants

Reaction Conditions

Reaction Steps

Lithium diisopropylamide (0.18 mol) in tetrahydrofuran (270 ml) is added to a mixture of ethyl (2-chloro-6-fluorophenyl)acetate (38.1 g, 0.175 mol) and THF (200 ml) at -70° C. The reaction mixture is stirred for 2 hours at about -70° C. 4-Methylcyclohexanecarboxylic acid chloride (28.25 g, 0.175 mol) is added and the reaction mixture is allowed to warm up to room temperature over night. The reaction mixture is then quenched with hydrochloric acid (5N, 60 ml) and most of the organic solvent is distilled off under reduced pressure. From the remainder the product is extracted with light petroleum (200 ml). The organic layer is separated, washed with water, dried with magnesium sulphate and concentrated in vacuo to yield a yellow oil (63.5 g). This is filtered through silica (light petroleum, 3% ethyl acetate) to yield a pale yellow oil (27.2 g). The product is used in the next step without further purification.

Provenance & Evidence