4,6-Diphenylpyran-2-imines (9) are rearranged by sodium ethoxide to the isomeric 2-pyridones (10), but the corresponding thiopyran-2-imines (21) do not rearrange to pyridine-2-thiones (25). The conversion (10)→(25) is effected by phosphorus pentasulphide. Certain pyridine-2-thiones (25) rearrange to 2-arylthiopyridines (27) on heating. The isomeric compounds are readily distinguished by their mass
4,6-二苯基
吡喃-2-
亚胺(9)被
乙醇钠重排为异构体2-
吡啶酮(10),但相应的
噻喃-2-
亚胺(21)没有重排为
吡啶-2-
硫酮(25) 。五
硫化二
磷实现了(10)→(25)的转化。某些
吡啶-2-
硫酮(25)在加热时重排为2-芳基
硫代
吡啶(27)。异构化合物的质谱很容易区分。讨论了nmr,uv和ir光谱。