1,4-Dibromobutane → cis-(2-Pyrrolidin-1-yl-cyclohexyl)-carbamic acid tert-butyl ester

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Reaction Steps

1-N-Boc-1,2-cis-cyclohexyldiamine 5 (CAS 184954-75-4) (1.65 g, 7.7 mmol) was dissolved in 100 mL acetonitrile. Potassium carbonate (5.3 g, 39 mmol) and 1,4-dibromobutane (2.8 g, 13 mmol) were added and the reaction mixture was refluxed overnight. The solvent was evaporated off. The residue was taken up in water and ethyl acetate and was extracted three times with ethyl acetate. The combined organic phases were dried on sodium sulfate, filtered and evaporated. Purification of the residue by flash chromatography on silica gel (dichloromethane/methanol/ammonia 100:0:0→140:10:1) yielded cis-(2-pyrrolidin-1-yl-cyclohexyl)-carbamic acid tert-butyl ester as a yellow liquid (1.82 g, 88%), MS: m/e=269.4 [(M+H)+].

Provenance & Evidence