Hydrazino alcohols (1 - 4) were converted with phenyl or 4-chlorophenyl isothiocyanate into their thiourea derivatives (5a,b, 6a,b, 9a,b and 10a,b) which then were cyclized by treatment with methyl iodide and alkali to furnish 2-[arylamino(imino)]perhydropyrido[1,2-rf][1,3,4]oxadiazines (7a,b) and perhydropyrrolo[1,2-d][1,3,4]oxadiazines (12a,b) and their 2-arylimino-3N-methyl derivatives (8a,b and 13b). The nmr spectra and X-ray crystallographic analysis indicated that the 1,3,4-oxadiazines adopt rigid cis- or trans-fused ring conformations, depending on the parent ring size and the 3N-substituent. It was found that in the unsubstituted 1,3,4-oxadiazines (7a,b and 12a,b) involving a potential tautomeric equilibrium, the amino form is most likely to predominate.
|Number of pages||16|
|Publication status||Published - dec. 1 1997|
ASJC Scopus subject areas
- Analytical Chemistry
- Organic Chemistry