Benzylamine → 2-Benzylamino-6-(t-butylamino)-3-chloro-5-fluoropyridine

To 10 ml of N-methylpyrrolidone was added 6.8 g of 2-(t-butylamino)-5-chloro-3,6-difluoropyridine together with 8.0 g of benzylamine, and the mixture was stirred at 150° C. for one day, and allowed to cool. After 80 ml of chloroform, the mixture was washed three times with 300 ml of distilled water. The chloroform layer was dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was subjected to column chromatography (silica gel, 100 g; eluent: chloroform:n-hexane, 1:1) to obtain about 7.0 g of the title compound as a pale brown crude oil.