Short-RInChIKey=SA-FUHFF-UHFFFADPSC-FHUKKBCWNJ-UHFFFADPSC-NUHFF-NUHFF-NUHFF-ZZZ

Dimethyl 4',5'-diamino-[1,1':2',1''-terphenyl]-4,4''-dicarboxylate (2.30 g, 6.11 mmol, 1.00 equiv) and ammonium chloride (163 mg, 3.06 mmol, 0.500 equiv) were dissolved in methanol (60.00 mL). Then butane-2,3-dione (579 mg, 579 μL, 6.72 mmol, 1.10 equiv) was added dropwise and the mixture was stirred at 21 °C for 12 h. Methylene chloride (200 mL) was added and the organic layer was washed with brine (200 mL). Then the aqueous layer was extracted 3x with methylene chloride (200 mL) each time. The combined organic layer were combined, dried over Na2SO4 and filtered. The solvent was removed under reduced pressure.