Abstract Hetero-Diels-Alder reactions of N-phosphoryltrihaloacetimidoyl chlorides with 1, 3- butadienes led to new 2-chloro-2-trihalomethyl substituted tetrahydropyridine adducts. Cycloadducts with CF3 group undergo thermal or acid catalyzed dehydrochlorination affording respective dihydropyridines and subsequent aromatization to form 2- trifluoromethylpyridines. Trichloromethyl analogs under similar conditions undergo ...
