Cyclohexylisopropylamine → Lithium cyclohexylisopropylamide

Participants

Reaction Conditions

Reaction Steps

In a 250 mL round bottomed flask a solution of lithiumisopropylcyclohexylamide was prepared from isopropylcyclohexylamine (6.21 g, 7.23 mL, 44 mmol) in THF (50 mL) and butyllithium (2.5M in hexane, 17.6 mL, 44 mmol). The solution was cooled to -78° C. under nitrogen and N,N-diethyl-3,3-dimethylacrylamide [109] (3.10 g, 20 mmol) in THF (20 mL) was added. After stirring for 30 min at -78° C., the solution was warmed to room temperature and stirred for 5 h. The reaction mixture was then cooled to -78° C., and 1,4-dibromoanisole [112] (5.852 g, 22 mmol) in THF (30 mL) was added via syringe. The solution was stirred at 0° C. for 24 h and then quenched with saturated aqueous ammonium chloride (100 mL) and diluted with ether (30 mL). The organic layer was separated and the aqueous layer was extracted with ether (3×40 mL). The combined organic layers were washed with brine (40 mL), dried with sodium sulfate and concentrated in vacuo to give 4.60 g of crude material. Flash chromatography of the crude material (hexane/ethyl acetate; 9:1) yielded product 113 (1.17 g, 22%) as a light yellow oil.

Provenance & Evidence