Naphthalene → 2,6-Diisopropylnaphthalene

Participants

Reaction Steps

Substantially pure 2,6-diisopropylnaphthalene can be recovered from the diisopropylnaphthalene products in a multi-stage separation scheme. In one embodiment, the diisopropylnaphthalene product is first fractionally distilled to obtain a low boiling fraction which contains unreacted naphthalene and monoisopropylnaphthalene, a middle fraction containing the diisopropylnaphthalenes, and a high boiling fraction containing triisopropylnaphthalene and tetraisopropylnaphthalenes. 2,6-diisopropylnaphthalene is obtained from the middle fraction by cooling the liquid to a temperature between 0° C. and -20° C. to fractionally crystallize the 2,6-isomer from the other diisopropylnaphthalenes. The mother liquor from the crystallization can be subjected to a second crystallization step, or it can then be combined with the low boiling and high boiling fractions, and subjected to transalkylation before recycle to the alkylation reactor, along with fresh naphthalene.

Provenance & Evidence