Réaction #53813

Équation de réaction

trans-(4-Hydroxy-cyclohexyl)-methyl-carbamic acid tert-butyl ester

1,4-Dibromobutane

NaOH

→

trans-[4-(4-Bromo-butoxy)-cyclohexyl]-methyl-carbamic acid tert-butyl ester

Rendement 76.0%

Solvants

CH2Cl2

Conditions de réaction

Traitement

1. 1
   workup.ADDITIONwere added
2. 2
   Autrethe layers were separated
3. 3
   ExtractionThe inorganic layer was extracted with CH2Cl2
4. 4
   Lavagethe combined organic layers washed with brine
5. 5
   Séchagedried over Na2SO4
6. 6
   AutreThe excess of dibromide was removed in vacuo
7. 7
   Autrethe residue was purified by column chromatography on silica gel with hexane:EtOAc 4:1 as eluent

Mode opératoire

To a suspension of 2.0 g (8.7 mmol) trans-(4-Hydroxy-cyclohexyl)-methyl-carbamic acid tert-butyl ester in 56.5 ml (261 mmol, 30 eq) 1,4-Dibromobutane, 0.89 g (2.6 mmol, 0.3 eq) tetrabutylammoniumhydrogensulfate and 56 ml 50% aqueous NaOH were added. The mixture was stirred at RT for 4 days, CH2Cl2 was added and the layers were separated. The inorganic layer was extracted with CH2Cl2, the combined organic layers washed with brine and dried over Na2SO4. The excess of dibromide was removed in vacuo and the residue was purified by column chromatography on silica gel with hexane:EtOAc 4:1 as eluent yielding 2.4 g (76%) trans-[4-(4-Bromo-butoxy)-cyclohexyl]-methyl-carbamic acid tert-butyl ester as light yellow oil, MS: 364 (MH+, 1Br).

Source