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

4,5-Diphenylbenzene-1,2-diamine (230 mg, 883 μmol, 1.00 equiv) and ammonium chloride (23.6 mg, 442 μmol, 0.500 equiv) were dissolved in methanol (5.00 mL). Then butane-2,3-dione (83.7 mg, 83.7 μL, 972 μmol, 1.10 equiv) was added dropwise and the mixture was stirred at 21 °C for 12 h. Methylene chloride (20 mL) and distilled water (20 mL) were added, the aquoues layer was extracted with methylene chloride x3 (20 mL). The combined organic phases were dried over Na2SO4, filtered and concentrated under reduced pressure