반응 #53842

반응 방정식

NaOH

trans-4-Hydroxy-cyclohexylcarbamic acid benzyl ester

1,6-Dibromohexane

→

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

수율 14.0%

용매

CH2Cl2

반응 조건

후처리

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

실험 절차

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).

출처