Method for making a di(aminoaryl)fluorene compound

A method for making a di(aminoaryl) fluorene compound, consisting essentially of:

• (a) reacting a fluorenone compound according structure (I):
• with excess aminobenzene according to structure (II):
• wherein:
• each R1, R2, R3, R4, R12, and R13 is independently a group that is inert in the polymerization of epoxy compounds, and
• R11 is H or (C1-C6)alkyl,
• in the presence of an acid catalyst,
• in a liquid medium comprising an aromatic or substituted aromatic solvent, that is non-reactive with the fluorenone compound of structure (I), having a boiling point of greater than or equal to 150° C. and from which the di(aminoaryl) fluorene compound is crystallizable, to form a crude product mixture comprising the di(aminoaryl) fluorene compound, wherein the acid catalyst is soluble in the liquid medium and is selected from the group consisting of:
• (i) Lewis acids having an affinity for oxygen, and (ii) Brønsted acids,
• (b) crystallizing di(aminoaryl) fluorene compound from the crude product mixture,
• (c) separating the product mixture into crystallized di(aminoaryl) fluorene compound and a filtrate, and, optionally, recycling at least a portion of the filtrate to step (a), wherein the filtrate comprises aromatic or substituted aromatic solvent having a boiling point of greater than or equal to 150° C., unreacted aminobenzene, di(aminoaryl) fluorene compound, and acid catalyst
• (d) washing, in one or more iterations, the di(aminoaryl) fluorene compound with aromatic or substituted aromatic solvent,
• (e) washing, in one or more iterations, the di(aminoaryl) fluorene compound produced in step (d) with water, a (C1-C4)alkanol, or a mixture thereof, and
• (f) drying the di(aminoaryl) fluorene compound produced in step (e).