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.

Abstract: Process for the recovery of phthalic anhydride in which gases as obtained in the catalytic atmospheric oxidation of o-xylene or naphthalene are treated with a hydrocarbon containing C.sub.26.sub.- paraffins, cooling, if necessary, the hydrocarbon laden with phthalic anhydride, separating the solid phthalic anhydride followed by melting and distillation thereof.