反应详情

温度

125 °C

A 300-mL autoclave was charged with 40 mL (0.50 mol) of 3,4-epoxy-1-butene, 67.3 g (0.66 mol) acetic anhydride, 5.82 g (0.097 mol) of acetic acid and 4.2 mL of diglyme. The autoclave was purged with nitrogen twice, then the vessel was pressurized to 8 bars (100 psig) with nitrogen. The agitator was started and an initial sample was taken. The mixture was heated to 125° C. During the course of 2.5 hrs, samples were taken every 15 min for analysis by GC. GC analysis of the crude mixture after 2.5 hrs revealed 11% yield of 3,4-diacetoxy-1-butene with a 13% selectivity, 21% 3,4-epoxy-1-butene and numerous high boiling components. The reaction was observed to be first order in 3,4-epoxy-1-butene with a first order rate constant (Kfirst) of 0.0025 min-1 (Table A). This example illustrates low yield and selectivity in the absence of a tertiary amine and the inefficient catalysis of the reaction in the presence of the carboxylic acid alone.

1. customThe autoclave was purged with nitrogen twice
2. waitGC analysis of the crude mixture after 2.5 hrs revealed