Journal: |
synthetic communications
Taylor & Francis
|
Volume: |
|
Abstract: |
An efficient and facile protocol for the synthesis of azine and azole
ring systems was reported. Whereas, reaction of cinnamoyl
isothiocyanate with N-nucleophile containing compounds (namely,
p-aminophenol (2), N1-phenylbenzene-1,4-diamine (5) and
p-aminoacetophenone (8)) tolerated thiourea derivatives 3, 6, and 9,
respectively. The later compounds underwent intramolecular cyclization
upon treatment with EtONa to give pyrimidinethiones 4, 7, and
10, respectively, in moderate yield (74–79%). Compound 9 underwent
intramolecular cyclization and condensation upon reaction with NaOH
and benzaldehyde to give pyrimidinethione 12. Thiosemicarbazides
14 and 19 were obtained through reaction of heteroallen 1 with
2,4-dinitrophenylhydrazine 13 and hydrazone 18, respectively.
Compound 14 was cyclized to pyrimidinethione 15 and triazine
derivatives 17 through its reaction with EtONa at room temperature
and refluxing temperature, respectively. Finally, base mediated and
oxidative cyclization of thiourea derivative 19 with EtONa, Br2/AcOH,
and Pb(OAc)2 afforded thiadiazole 20, benzothiazolotriazole 21, and
triazolethione 22 derivatives, respectively.
|
|
|