Potassium Iodide → tert-Butyl (3RS,5SR)-4-(2-ethoxy-2-oxoethyl)-3,5-dimethylpiperazine-1-carboxylate

Participants

Reaction Steps

2.0 g (9.33 mmol) of tert-butyl (3RS,5SR)-3,5-dimethylpiperazine-1-carboxylate (preparation: Helvetica Chimica Acta 1990, 73 (4), 839-855), 2.3 g (18.67 mmol) of ethyl chloroacetate, 3.9 g (28.00 mmol) of potassium carbonate and 0.5 g (2.80 mmol) of potassium iodide are stirred under reflux overnight in 80 ml of acetonitrile. For the work-up, some of the acetonitrile is removed on a rotary evaporator, and the residue is diluted with ethyl acetate, subsequently washed twice with water and once with a saturated sodium chloride solution. The combined aqueous phases are extracted once with ethyl acetate, the combined organic phases are dried over sodium sulfate, and the solvent is removed completely on a rotary evaporator. The residue is taken up in cyclohexane and after subsequent elution over silica gel 60 using subatmospheric pressure (cyclohexane/ethyl acetate 100/10→80/10→40/10) 2.5 g (88% of theory) of product are obtained.

Provenance & Evidence