Abstract: A process for the continuous preparation of alkyl pentenoates comprises the following steps:a) reaction of a butadiene-containing C.sub.4 cut with an alkanol and carbon monoxide in the presence of a cobalt carbonyl catalyst and heterocyclic aromatic tertiary nitrogen base at from 100.degree. to 160.degree. C. and under from 100 to 1,200 bar andb) treatment of the resulting reaction mixture, at the rate at which it is obtained, in a treatment zone, at from 100.degree. to 160.degree. C. under from 250 to 1,200 bar with a residence time of from 5 to 60 minutes, substantially without back-mixing.

Abstract: Alkyl pentenoates are prepared by reacting butadiene with carbon monoxide and an alkanol in the presence of a cobalt carbonyl complex and a tertiary, aromatic heterocyclic nitrogen base at from 80.degree. to 160.degree. C. under from 100 to 1,000 bar in the presence of from 0.1 to 10% by volume of hydrogen, based on the amount of carbon monoxide used.

Abstract: 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 obt

Abstract: Carbalkoxy-containing aliphatic compounds are prepared continuously by reacting an olefinically unsaturated aliphatic compound with carbon monoxide and an alkanol in the presence of a cobalt carbonyl catalyst and a tertiary nitrogen base at from 80.degree. to 200.degree. C. and under from 100 to 1,200 bar by an improved process in which carbon monoxide is circulated, and a carbon dioxide content of from 0.1 to 2% by volume is maintained in the carbon monoxide fed to the reaction.

Abstract: C.sub.1 -C.sub.4 -alkyl pentenoates are obtained from reaction mixtures which contain this and which are obtained by reacting butadiene, or a butadiene-containing hydrocarbon mixture, with carbon monoxide and a C.sub.1 -C.sub.4 -alkanol, in the presence of a cobalt carbonyl catalyst and a tertiary nitrogen base at elevated temperatures and under superatmospheric pressure by a process in which(a) the liquid reaction mixture freed from excess carbon monoxide is treated with hydrogen at elevated temperatures and under from 5 to 80 bar,(b) hydrocarbons are distilled off from the resulting liquid reaction mixture,(c) the C.sub.1 -C.sub.4 -alkyl pentenoate, the alkanol and the nitrogen base are then distilled off under reduced pressure, and(d) the C.sub.1 -C.sub.4 -alkyl pentenoate is obtained by fractional distillation from the distillate containing this compound, the alkanol and the tertiary nitrogen base.