反应详情

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.

1. customFor the work-up, some of the acetonitrile is removed on a rotary evaporator
2. additionthe residue is diluted with ethyl acetate
3. washsubsequently washed twice with water and once with a saturated sodium chloride solution
4. extractionThe combined aqueous phases are extracted once with ethyl acetate
5. dry with materialthe combined organic phases are dried over sodium sulfate
6. customthe solvent is removed completely on a rotary evaporator
7. washafter 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
8. customare obtained