メチルピリジン誘導体の合成(第23報) : 2,6-Lutidine誘導体のクロル化反応

抄録

Treatment of 3-nitro-2, 6-dimethyl-4-pyridinol (I) with phosphoryl chloride gives 3-nitro-4-chloro-2, 6-dimethyl-pyridine (II) in 61% yield, and the use of phosphoryl chloride and excess of phosphorus pentachloride results in chlorination of the side chain to give 2-tri-chloromethyl-3-nitro-4-chloro-6-methylpyridine (III) in 45% yield. In a similar manner, use of excess phosphorus pentachloride on 2, 6-dimethylpyridine (V) gave a minute amount of 4-chloro-2, 6-dimethylpyridine (VI) and 2-chloromethyl-6-methylpyridine (VII), as well as 2, 6-bis (trichloromethyl) pyridine (VIII) in 3% yield, and 2-trichloromethyl-3-nitro-6-methylpyridine (X) in 38% yield from 3-nitro-2, 6-dimethylpyridine (IX). The same treatment of 2, 6-dime-thyl-4-pyridinol (XI) gave 4-chloro-2, 6-dimethylpyridine (VI) in 68% yield and a minute amount of 2-trichloromethyl-4-chloro-6-methylpyridine (XII).