Process for preparing heterocycles

A process for preparing a heterocycle of the following formula (I) by catalytic reaction of an aromatic dinitrile of the following formula (II) with an amino alcohol of the following formula (III):

• wherein R1, R2, R3, R4, R5 and R6, may be the same or different, and are each independently selected from the group consisting of a hydrogen atom, an alkyl group, an aryl group, a —COOH group and an —NH2 group, and n is an integer of from 0 to 4,
• wherein said process comprises:
• initially charging into a reaction vessel the amino alcohol of formula (III) and a catalyst to produce a reaction mixture;
• adding the aromatic dinitrile of formula (II) into the reaction mixture, which is maintained at a reaction temperature, wherein no solvent other than the amino alcohol of formula (III) is added to the reaction mixture prior to and/or during the catalytic reaction;
• and
• after completion of the catalytic reaction, completely replacing, or substantially completely replacing, unreacted amino alcohol of formula (III) with a nonpolar solvent to obtain the heterocycle of formula (I), wherein the unreacted amino alcohol of formula (III) is present in an amount of not more than 20 wt. %, based on a total weight of the heterocycle of formula (I).