Condensed pyridines. 6. Synthesis and strucutre of adamantyl-, cyclopropyl- and alkyl-substituted 3-halomethyl-2,3-dihydro-8-cyanothiazolo[3,2-a]pyridinium salts and their oxazolo and selenazolo derivatives
The reaction of substituted 2-cyanopyridin-2(1H)-ones and their thione and selenone derivatives with allyl bromide gives the corresponding 2-allyloxy-, 2-allylmercapto-, and 2-allylseleno-3-pyridines, which upon treatment with halogens, form intramolecular quaternization products, namely, 3-halomethyl-2,3-dihydro-8-cyanooxazole[3,2-a]pyridinium salts and their thiazolo and selenazolo analogs. X-ray diffraction structural analysis was used to determine the structure of 3-bromomethyl-2,3-dihydro-5,7-dimethyl-8-cyanothiazolo[3,2-a]pyridinium perchlorate.