反应详情

22.5 g (0.18 mol) of o-aminothiophenol, 25 g (0.18 mol) of 5-methylpicolic acid and 100 g of polyphosphoric acid were admixed and stirred in nitrogen gas streams at 170°-200° C. and the mixture was poured in 1 l of water. The mixture was adjusted to pH 5 with an aqueous solution of sodium hydroxide and the resulting crystals were recovered by filtration, whereupon 40 g of 2-(benzothiazol-2-yl)-5methylpyridine was obtained as crude crystals. This crude product was recrystallized from ligroine. By the above procedure was obtained 36 g of the same compound as colorless flakes melting at 169.5°-170.0° C.

1. filtrationthe resulting crystals were recovered by filtration, whereupon 40 g of 2-(benzothiazol-2-yl)-5methylpyridine
2. customwas obtained as crude crystals
3. customThis crude product was recrystallized from ligroine