Synthesis
General procedure: 4-nitroisophthalic acid (98 g, 0.457 mol) was dissolved in methanol (5 L) and 20% Pd/C catalyst was added. The hydrogenation reaction was carried out at room temperature for 4 hours. Upon completion of the reaction, the mixture was filtered through diatomaceous earth to remove the catalyst. The filtrate was concentrated in vacuum to afford 4-aminoisophthalic acid (72 g, 87% yield) as a white solid. The product was detected by thin layer chromatography (TLC) with chloroform/methanol (7:3) as the unfolding agent and an Rf value of 0.4.
References
[1] Patent: WO2005/11686, 2005, A1. Location in patent: Page 38
[2] Patent: WO2004/7491, 2004, A1. Location in patent: Page 57
[3] Farmaco, Edizione Scientifica, 1984, vol. 39, # 11, p. 968 - 978
[4] Patent: US2008/280900, 2008, A1
[5] Patent: US6635657, 2003, B1
