Hydroformylation process for producing 1,6-disubstituted hexane derivatives

A process for the production of a compound of the formula (I)

• wherein
• X are both CH2NH2, CH2OH or COOH,
• R1 and R2 are independently from each other hydrogen or linear or branched C1-C4-alkyl,
• comprising the following steps:
• i) subjecting at least one compound of the formula (II)
• wherein R1 and R2 have the same meaning as in formula (I),
• to a hydroformylation with carbon monoxide and hydrogen in the presence of at least one transition metal catalyst,
• wherein the hydroformylation is performed in the presence of at least one alkanol of the formula (III)
• HO—Z—OH (III)
• wherein
• Z is a hydrocarbon chain having 2 or 3 carbon atoms which is unsubstituted or substituted and which may be part of a carbocycle, a heterocycle or an aromatic or heteroaromatic ring,
• wherein during the hydroformylation the temperature is increased for at least 10° C. from a temperature T1 to a temperature T2,
• to obtain a reaction mixture comprising at least one compound selected from the compounds of the formula (IV.a) and (IV.b),
• wherein
• Z has the same meaning as in formula (III), and
• R1 and R2 have the same meaning as in formula (I),
• ii) subjecting the reaction mixture obtained in step i) to a separation to obtain a fraction enriched with at least one compound selected from the compounds of the formula (IV.a) and (IV.b) and a fraction depleted with at least one compound selected from the compounds of the formula (IV.a) and (IV.b),
• iii) optionally recycling at least partially the fraction depleted with at least one compound selected from the compounds of the formula (IV.a) and (IV.b) obtained in step ii) to step i), and
• iv) subjecting the fraction enriched with at least one compound selected from the compounds of the formula (IV.a) and (IV.b) obtained in step ii) to a reaction in which the acetal groups in the compounds of the formula (IV.a) and (IV.b) are reacted to obtain the compound of the formula (I).