124293-43-2Relevant articles and documents
Synthesis and reactions of 2,3-dihydrocyclohepta[b][1,4]-thiazines and 2,3-dihydro-1H-cyclohepta[b]pyrazines
Nozoe, Tetsuo,Ishikawa, Sumio,Shindo, Kimio
, p. 733 - 744 (2007/10/02)
The reaction of 2-methoxytropone with ethylenediamine gave 2-(2-aminoethyl)aminotropone and 2,2′-(1,2-ethanediamino)-bis(tropone), and the former afforded 2,3-dihydro-1H-cyclohepta[b]pyrazine (13) on heating. N-Methyl compound 14 of 13 was also obtained by the similar method. 14 was led to the dimethyl cation 18b, which gave exclusively 7-bromo compound 24 with bromine in acetic acid. 18b and 24 rearranged to 1,2,3,4-tetrahydro-1, 4-dimethylquinoxaline-6-carbaldehyde with alkali, while 13 rearranged to 1-phenylimidazolin-2-one on treatment with H2O2. The reaction of 2-chlorotropone with 2-aminoethanethiol rapidly afforded 2-(2-aminoethylthio)tropone (35a), which gradually changed to 2-[2-(2-troponyl)thioethylamino]tropone (37a) and N,N′-bis(2-troponyl)-2-aminoethanedisulfide (39a) via unstable 2-(2-mercaptoethyl)-aminotropone (38a). Hydrochloride of 35a gave, upon heating, 2, 3-dihydrocyclohepta[b] [1,4]thiazine (15), which gave N-methyl cation 40 on treatment with magic methyl. 40 gradually changed with cold alkali to the disulfide 39b, via 35b, 37b, and 38b, in a manner similar to the case of their parent compounds (35a, 37a, and 38a). Possible pathways of these reactions, especially the facile exchange of the difunctionalized side-chains, are discussed.
