Adipic Acid → epsilon-CAPROLACTONE

Participants

Reaction Steps

To prepare hexane-1,6-diol, for example, it is known to hydrogenate adipic acid or its salts directly, in aqueous solution or in an organic solvent, by a batchwise (DE-A-26 05 107; GB 1,300,889) or continuous (DE-A-23 21 101) procedure in which, alongside hexane-1,6-diol, relatively large proportions of caprolactone, ω-hydroxy-caproic acid and monoalcohols with carbon numbers from 1 to 6 are always formed. For the same purpose, it is also known to esterify adipic acid with monoalcohols, to give a di-n-alkyl adipate which is hydrogenated in the gas phase to give hexane-1,6-diol (WO 82/03854). It is also known to esterify adipic acid with diols, such as hexane-1,6-diol, by a batchwise procedure to give a mixture of higher esters, which is hydrogenated in a batchwise autoclave process to give hexane-1,6-diol and ω-hydroxy-caproic esters, the hydrogenation catalyst employed being a pulverulent copper chromite catalyst (DE-B-10 23 750).

Provenance & Evidence