Step 2: Synthesis of N1,N1-dimethylbenzene-1,3-diamine
N,N-dimethyl-3-nitroaniline (1.0 g, 6.08 mmol) prepared in Step 1 was dissolved in methanol (25 mL) and 10% palladium carbon (Pd/C, 100 mg) was added. The reaction mixture was hydrogenated in a hydrogen atmosphere for 15 hours at room temperature. Upon completion of the reaction, the palladium carbon catalyst was removed by diatomaceous earth filtration and the filtrate was concentrated to dryness under reduced pressure. The resulting residue was purified by fast column chromatography (eluent: hexane/ethyl acetate=1:1, v/v) to afford N1,N1-dimethylbenzene-1,3-diamine (700 mg, yield: 90%, colorless liquid).
1H NMR (400MHz, CDCl3) δ: 7.04 (t, J=7.6Hz, 1H), 6.2 (d, J=8.0Hz, 1H), 6.11-6.08 (m, 1H), 3.60 (br s, 2H), 2.92 (s, 6H).
