A novel efficient method for the synthesis of diaminotriphenylmethanes (DTMs) in high yield through one-step condensation of arylaldehydes and N,N-dimethylaniline catalyzed by polymer-supported sulfonic acid (NKC-9) is described. This method offers the advantages of mild reaction condition, simplicity and reuse of the catalyst. © 2007 Elsevier Ltd. All rights reserved.
An, L. T., Ding, F. Q., & Zou, J. P. (2008). The polymer-supported sulfonic acid catalyzed one-step synthesis of diaminotriphenylmethanes. Dyes and Pigments, 77(2), 478–480. https://doi.org/10.1016/j.dyepig.2007.06.004