1-Butanol → Dibutyl carbonate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A 160 cc Parr autoclave was charged with 2.22 g (0.03 mol) butanol, 6.9 g (0.035 mol) N-cyclohexyl-N',N',N",N"-tetramethylguanidine and 30 mL CH3CN. The autoclave was attached to a pressure head and at room temperature with stirring was added 160 psig carbon dioxide. Addition of CO2 resulted in an exothermic reaction with a rise in temperature to ca. 40° C. Into a Fischer-Porter bottle was added 8.33 g (0.09 mol) butyl chloride in 10 mL CH3CN. This mixture was attached to a pressure head and 80 psig carbon dioxide was added above the solution. After 1 h the butyl chloride solution was added all at once under 80 psig CO2 to the pre-formed carbamate anion solution generated in the autoclave. After addition the pressure was raised to 160 psig with carbon dioxide and the reaction mixture was warmed to 85° C. for 16 h. After this time the reaction mixture was allowed to cool to room temperature and then the pressure was released. An aliquot was taken, diluted with diethyl ether, Cl-+HCyTMG filtered off and by G.C. analysis a 73% yield of dibutyl carbonate was calculated. Oil 1H NMR (CDCl3) 4.14(t, J=6.6 Hz, 4H), 1.66 (m, 4H), 1.41 (m, 4H), 0.94 (t, J=7.3 Hz, 6H). 13C{1H} NMR (CDCl3) 155.9, 68.2, 31.2, 19.4, 14.1. IR (film) 1746, 1260; MS (FAB) m/z=175 (MH+).

Herkunft & Nachweise