Process for the preparation of formylvaleric acid and adipic acid

The invention relates to a process for the production of 5-formylvaleric acid and adipic acid or esters thereof from an isomeric mixture of pentenoic acid or esters thereof said mixture comprising at least 4-pentenoic acid or esters thereof, and further comprising 3-pentenoic acid and/or 2-pentenoic acid or esters thereof, theprocess comprising: (a) subjecting the isomeric mixture of pentenoic acid to a hydroformylation reaction comprising a hydroformylation catalyst which is non-isomerizing towards the pentenoic acid or esters thereof to obtain a mixture comprising 5-formylvaleric acid or esters thereof and further comprising 3-pentenoic acid and/or 2-pentenoic acid, or esters thereof; (b) separating the 3-pentenoic acid and/or 2-pentenoic acid, or esters thereof from the 5-formylvaleric acid or esters thereof; (c) subjecting the separated pentenoic acids or esters thereof to a carbonylation reaction comprising an isomerizing carbonylation catalyst to obtain adipic acid or esters thereof; (d) optionally isolating the adipic acid or ester thereof; and (e) optionally isolating the separated 5-formylvaleric acid or esters thereof. The process allows for efficient production of two different intermediates for producing polyamide using a single process, with good selectivity, little waste, in an economically efficient fashion. The process is very suitable to use an isomeric pentenoic acid mixture obtained from valerolactone, and can be used to produce renewable polyamide intermediates using a single process.