Water → 2-Chloro-N4-methylpyridine-3,4-diamine

A solution of methyl-(3-nitro-pyridin-4-yl)amine (7.00 g) in concentrated hydrochloric acid (150 mL) was heated to 90° C. Tin(II) chloride dihydrate (52.2 g) was then added, and this was heated at 90° C. for 30 minutes. The reaction solution was cooled to 0° C., iced water (700 mL) was added, and this was stirred for 30 minutes. The solution was concentrated under reduced pressure, and then ammonia-saturated methanol solution (700 mL) was added to the residue, and this was stirred at 5° C. for 15 hours. The solvent was removed by concentration under reduced pressure. The residue was suspended in ethyl acetate (500 mL), and this was filtered through celite. The celite and the suspended material were washed five times with 250 mL of ethyl acetate, then the organic layers were combined, and this was concentrated under reduced pressure to give the title compound (7.22 g).