Réaction #53842

Équation de réaction

NaOH

trans-4-Hydroxy-cyclohexylcarbamic acid benzyl ester

1,6-Dibromohexane

→

trans-[4-(6-Bromo-hexyloxy)-cyclohexyl]-carbamic acid benzyl ester

Rendement 14.0%

Solvants

CH2Cl2

Conditions de réaction

Traitement

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

Mode opératoire

To 15.0 g (60 mmol) trans-4-Hydroxy-cyclohexylcarbamic acid benzyl ester suspended in 183 ml (1.2 mol, 20 eq) 1,6-Dibromohexane, 6.1 g (18 mmol, 0.3 eq) tetrabutyl-ammoniumhydrogensulfate and 183 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 were 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 1:1 as eluent yielding 3.4 g (14%) trans-[4-(6-Bromo-hexyloxy)-cyclohexyl]-carbamic acid benzyl ester as white solid, MS: 412 (MH30, 1Br) and 11.2 g (32%) trans-(6-Bromo-hexyl)-[4-(6-bromo-hexyloxy)-cyclohexyl]-carbamic acid benzyl ester as yellow oil, MS: 574 (MH+, 2Br).

Source