abstract |
The present invention is directed to a process for the preparation of l,3:2,4-bis (4- methylbenzylidene) sorbitol (MDBS) and 1,3:2,4-bis (4-dimethylbenzylidene) sorbitol (DMDBS) by dehydrocondensating an aldehyde and an alditol using a hydrophobic ionic liquid as an acid catalyst. The ionic liquid used in the accordance with the process of the present invention is a phosphonium ion based ionic liquid. |