Pentenoate ester cpds. prodn. by hydroesterification of butadiene - in medium contg. at least two solvents of pyridine, quinoline and isoquinoline type

摘要

In the prodn. of 3-pentenoate esters (I) by reacting butadiene (II), CO and an alcohol (III) in the presence of a Co carbonyl catalyst (IV), the reaction is carried out in a medium contg. at least 2 solvents from the gp. (substd.) pyridine and (substd.) (iso)quinoline, the substit(s). being 1-6C alk(en)yl or 7-10C alkylaryl or aralkyl. Pref. one of the solvents is pref. present in an amt. of min. 2 mole-% w.r.t. the total molar amt. of solvents, whilst the combined amt. of the solvents is 0.05-10 (wt.) pts./pt. (II). Pref. (IV) is Co2(CO)8 (IVA) and is used in an amt. of 0.001-0.05 mole/mole (II). (III) is pref. used in an amt. of over 1 mole/mole (II). Reaction is pref. carried out at 80-200 deg.C and a CO partial pressure of over 50 bar, pref. in the presence of a polymerisation inhibitor, i.e. an aromatic amine or OH cpd. (except hydroquinone) or quinone cpd. in an amt. of over 0.0001 mole/mole (II). Less (IV) is needed, since its activity is higher than usual, the (I) yield and selectivity are increased and the process is suitable for continuous or batch operation.