| 摘要 |
Pyridine or methylpyridines or mixtures thereof are recovered from methyl butanedicarboxylate containing reaction mixtures obtained by reaction of methyl pentenoate with carbon monoxide and methanol in the presence of pyridine, methylpyridines or mixtures thereof and also cobalt catalysts at elevated temperatures and under superatmospheric pressure and subsequent treatment with molecular oxygen containing gases in aqueous acetic acid by (a) separating the reaction mixture on the one hand into an aqueous phase containing cobalt acetate, pyridine, methylpyridines or mixtures thereof, acetic acid and methanol and on the other an organic phase containing methyl butanedicarboxylate, by-products, unconverted methyl pentenoate, acetic acid and also pyridine, methylpyridines or mixtures thereof, (b) extracting the organic phase obtained in step (a) with aqueous acetic acid to obtain an aqueous extract containing pyridine or methylpyridines or mixtures thereof as well as acetic acid, (c) combining the aqueous extract obtained in step (b) with the aqueous phase from step (a) and (d) isolating pyridine, methylpyridines or mixtures thereof by distillation from the aqueous solution produced in step (c) and obtaining a solution of cobalt acetate in aqueous acetic acid. |
