[NH2:1][C:2]1[C:11]([NH2:12])=[CH:10][C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[CH:3]=1.[H-].[Na+].[CH3:15]I>CN(C)C=O.C(OCC)(=O)C>[NH2:1][C:2]1[C:11]([NH:12][CH3:15])=[CH:10][C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[CH:3]=1A solution of 2,3-diaminonaphthalene (500 mg, 3.16 mmol) in anhydrous dimethylformamide (3 mL) was cooled in an ice bath and treated with sodium hydride (130 mg of a 61% dispersion in mineral oil, 3.31 mmol). The mixture was stirred at 0-5° C. for 7 minutes, then treated with methyl iodide (0.206 mL, 3.31 mmol) and stirred in the cold for an additional 15 minutes. After warming to room temperature, the mixture was diluted with ethyl acetate (30 mL), washed with water (5×30 mL) and brine (20 mL), dried over magnesium sulfate, filtered, and evaporated under vacuum to a dark solid (0.5 g). The crude product was purified by silica gel chromatography (2.75×24 cm column) using 5% ethyl acetate in dichloromethane as eluting solvent. The product fractions were combined and evaporated to afford 2-amino-3-methylamino-naphthalene (168 mg) as a solid.
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